jtx Board support (see bitfireAT/davx5#38)

Initial support for jtx Board

79 files changed, 5048 insertions, 243 deletions

diff --git a/src/androidTest/java/at/bitfire/ical4android/AbstractTasksTest.kt b/src/androidTest/java/at/bitfire/ical4android/AbstractTasksTest.kt
index fe5425f..16431eb 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AbstractTasksTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AbstractTasksTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import androidx.test.platform.app.InstrumentationRegistry
@@ -16,7 +20,7 @@ abstract class AbstractTasksTest(
     companion object {
         @Parameterized.Parameters(name="{0}")
         @JvmStatic
-        fun taskProviders() = TaskProvider.ProviderName.values()
+        fun taskProviders() = listOf(TaskProvider.ProviderName.OpenTasks,TaskProvider.ProviderName.TasksOrg)
     }
 
     private val providerOrNull: TaskProvider? by lazy {
diff --git a/src/androidTest/java/at/bitfire/ical4android/AndroidCalendarTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidCalendarTest.kt
index 09c587f..d754f9d 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AndroidCalendarTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidCalendarTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/AndroidEventTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidEventTest.kt
index a4bba3b..00ac8ce 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AndroidEventTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidEventTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 package at.bitfire.ical4android
 
 import android.Manifest
diff --git a/src/androidTest/java/at/bitfire/ical4android/AndroidTaskListTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidTaskListTest.kt
index 8d6afa3..f7e9398 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AndroidTaskListTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidTaskListTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/AndroidTaskTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidTaskTest.kt
index 7b6f945..c907439 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AndroidTaskTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidTaskTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/AndroidTimeZonesTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidTimeZonesTest.kt
index 974910b..d51c1ad 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AndroidTimeZonesTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidTimeZonesTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import org.junit.Assert
diff --git a/src/androidTest/java/at/bitfire/ical4android/AttendeeMappingsTest.kt b/src/androidTest/java/at/bitfire/ical4android/AttendeeMappingsTest.kt
index df507e8..69e0842 100644
--- a/src/androidTest/java/at/bitfire/ical4android/AttendeeMappingsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AttendeeMappingsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import android.content.ContentValues
diff --git a/src/androidTest/java/at/bitfire/ical4android/Ical4jSettingsTest.kt b/src/androidTest/java/at/bitfire/ical4android/Ical4jSettingsTest.kt
index 7f43b8a..7386ef4 100644
--- a/src/androidTest/java/at/bitfire/ical4android/Ical4jSettingsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/Ical4jSettingsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.util.TimeZones
diff --git a/src/androidTest/java/at/bitfire/ical4android/JtxCollectionTest.kt b/src/androidTest/java/at/bitfire/ical4android/JtxCollectionTest.kt
new file mode 100644
index 0000000..e1478fe
--- /dev/null
+++ b/src/androidTest/java/at/bitfire/ical4android/JtxCollectionTest.kt
@@ -0,0 +1,96 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentResolver
+import android.content.ContentValues
+import android.content.Context
+import androidx.test.platform.app.InstrumentationRegistry
+import at.bitfire.ical4android.MiscUtils.ContentProviderClientHelper.closeCompat
+import at.bitfire.ical4android.impl.TestJtxCollection
+import at.techbee.jtx.JtxContract
+import at.techbee.jtx.JtxContract.asSyncAdapter
+import junit.framework.TestCase.assertEquals
+import junit.framework.TestCase.assertNotNull
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+
+class JtxCollectionTest {
+
+    private val testAccount = Account("TEST", JtxContract.JtxCollection.TEST_ACCOUNT_TYPE)
+    private lateinit var contentResolver: ContentResolver
+    private lateinit var client: ContentProviderClient
+    var collection: JtxCollection<JtxICalObject>? = null
+    lateinit var context: Context
+
+    private val url = "https://jtx.techbee.at"
+    private val displayname = "jtx"
+    private val syncversion = JtxContract.VERSION
+
+    private val cv = ContentValues().apply {
+        put(JtxContract.JtxCollection.ACCOUNT_TYPE, testAccount.type)
+        put(JtxContract.JtxCollection.ACCOUNT_NAME, testAccount.name)
+        put(JtxContract.JtxCollection.URL, url)
+        put(JtxContract.JtxCollection.DISPLAYNAME, displayname)
+        put(JtxContract.JtxCollection.SYNC_VERSION, syncversion)
+    }
+
+    @Before
+    fun setUp() {
+        context = InstrumentationRegistry.getInstrumentation().targetContext
+        contentResolver = context.contentResolver
+        TestUtils.requestPermissions(TaskProvider.ProviderName.JtxBoard.permissions)
+        client = contentResolver.acquireContentProviderClient(JtxContract.AUTHORITY)!!
+    }
+
+    @After
+    fun tearDown() {
+        var collections = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)
+        collections.forEach { collection ->
+            collection.delete()
+        }
+        collections = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)
+        assertEquals(0, collections.size)
+        client.closeCompat()
+    }
+
+
+    @Test
+    fun create_populate_find() {
+        val collectionUri = JtxCollection.create(testAccount, client, cv)
+        assertNotNull(collectionUri)
+        val collections = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)
+
+        assertEquals(1, collections.size)
+        assertEquals(testAccount.type, collections[0].account.type)
+        assertEquals(testAccount.name, collections[0].account.name)
+        assertEquals(url, collections[0].url)
+        assertEquals(displayname, collections[0].displayname)
+        assertEquals(syncversion.toString(), collections[0].syncstate)
+    }
+
+    @Test
+    fun queryICalObjects() {
+        val collectionUri = JtxCollection.create(testAccount, client, cv)
+        assertNotNull(collectionUri)
+
+        val collections = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)
+        val items = collections[0].queryICalObjects(null, null)
+        assertEquals(0, items.size)
+
+        val cv = ContentValues().apply {
+            put(JtxContract.JtxICalObject.SUMMARY, "summary")
+            put(JtxContract.JtxICalObject.COMPONENT, JtxContract.JtxICalObject.Component.VJOURNAL.name)
+            put(JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID, collections[0].id)
+        }
+        client.insert(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)
+        val icalobjects = collections[0].queryICalObjects(null, null)
+
+        assertEquals(1, icalobjects.size)
+    }
+}
diff --git a/src/androidTest/java/at/bitfire/ical4android/JtxICalObjectTest.kt b/src/androidTest/java/at/bitfire/ical4android/JtxICalObjectTest.kt
new file mode 100644
index 0000000..9527dba
--- /dev/null
+++ b/src/androidTest/java/at/bitfire/ical4android/JtxICalObjectTest.kt
@@ -0,0 +1,866 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentResolver
+import android.content.ContentValues
+import android.content.Context
+import android.database.DatabaseUtils
+import android.os.ParcelFileDescriptor
+import androidx.test.platform.app.InstrumentationRegistry
+import at.bitfire.ical4android.impl.TestJtxCollection
+import at.techbee.jtx.JtxContract
+import at.techbee.jtx.JtxContract.JtxICalObject
+import at.techbee.jtx.JtxContract.JtxICalObject.Component
+import at.techbee.jtx.JtxContract.asSyncAdapter
+import junit.framework.TestCase.*
+import net.fortuna.ical4j.model.Calendar
+import net.fortuna.ical4j.model.Property
+import org.junit.After
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Test
+import java.io.ByteArrayOutputStream
+import java.io.InputStreamReader
+
+class JtxICalObjectTest {
+
+    private val testAccount = Account("TEST", JtxContract.JtxCollection.TEST_ACCOUNT_TYPE)
+    private lateinit var contentResolver: ContentResolver
+    private lateinit var client: ContentProviderClient
+    var collection: JtxCollection<at.bitfire.ical4android.JtxICalObject>? = null
+    var sample: at.bitfire.ical4android.JtxICalObject? = null
+    lateinit var context: Context
+
+    private val url = "https://jtx.techbee.at"
+    private val displayname = "jtxTest"
+    private val syncversion = JtxContract.VERSION
+
+    private val cvCollection = ContentValues().apply {
+        put(JtxContract.JtxCollection.ACCOUNT_TYPE, testAccount.type)
+        put(JtxContract.JtxCollection.ACCOUNT_NAME, testAccount.name)
+        put(JtxContract.JtxCollection.URL, url)
+        put(JtxContract.JtxCollection.DISPLAYNAME, displayname)
+        put(JtxContract.JtxCollection.SYNC_VERSION, syncversion)
+    }
+
+    @Before
+    fun setUp() {
+        context = InstrumentationRegistry.getInstrumentation().targetContext
+        contentResolver = context.contentResolver
+        TestUtils.requestPermissions(TaskProvider.ProviderName.JtxBoard.permissions)
+        client = contentResolver.acquireContentProviderClient(JtxContract.AUTHORITY)!!
+
+        val collectionUri = JtxCollection.create(testAccount, client, cvCollection)
+        assertNotNull(collectionUri)
+        collection = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)[0]
+        assertNotNull(collection)
+
+        sample = JtxICalObject(collection!!).apply {
+            this.summary = "summ"
+            this.description = "desc"
+            this.dtstart = System.currentTimeMillis()
+            this.dtstartTimezone = "Europe/Vienna"
+            this.dtend = System.currentTimeMillis()
+            this.dtendTimezone = "Europe/Paris"
+            this.status = JtxICalObject.StatusJournal.FINAL.name
+            this.classification = JtxICalObject.Classification.PUBLIC.name
+            this.url = "https://jtx.techbee.at"
+            this.contact = "jtx@techbee.at"
+            this.geoLat = 48.2082
+            this.geoLong = 16.3738
+            this.location = "Vienna"
+            this.locationAltrep = "Wien"
+            this.percent = 99
+            this.priority = 1
+            this.due = System.currentTimeMillis()
+            this.dueTimezone = "Europe/Berlin"
+            this.completed = System.currentTimeMillis()
+            this.completedTimezone = "Europe/Budapest"
+            this.duration = "P15DT5H0M20S"
+            this.rrule = "FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9;BYMINUTE=30"
+            this.exdate = System.currentTimeMillis().toString()
+            this.rdate = System.currentTimeMillis().toString()
+            this.recurid = "1635796608864-b228364a-e633-449a-aeb2-d1a96941377c@at.techbee.jtx"
+            this.uid = "1635796608864-b228364a-e633-449a-aeb2-d1a96941377c@at.techbee.jtx"
+            this.created = System.currentTimeMillis()
+            this.lastModified = System.currentTimeMillis()
+            this.dtstamp = System.currentTimeMillis()
+            this.sequence = 1
+            this.color = -2298423
+            this.dirty = false
+            this.deleted = false
+            this.fileName = "test.ics"
+            this.eTag = "0"
+            this.scheduleTag = "0"
+            this.flags = 0
+        }
+
+    }
+
+    @After
+    fun tearDown() {
+
+        collection?.delete()
+        val collections = JtxCollection.find(testAccount, client, context, TestJtxCollection.Factory, null, null)
+        assertEquals(0, collections.size)
+    }
+
+
+    @Test fun check_SUMMARY() = insertRetrieveAssertString(JtxICalObject.SUMMARY, sample?.summary, Component.VJOURNAL.name)
+    @Test fun check_DESCRIPTION() = insertRetrieveAssertString(JtxICalObject.DESCRIPTION, sample?.description, Component.VJOURNAL.name)
+    @Test fun check_DTSTART() = insertRetrieveAssertLong(JtxICalObject.DTSTART, sample?.dtstart, Component.VJOURNAL.name)
+    @Test fun check_DTSTART_TIMEZONE() = insertRetrieveAssertString(JtxICalObject.DTSTART_TIMEZONE, sample?.dtstartTimezone, Component.VJOURNAL.name)
+    @Test fun check_DTEND() = insertRetrieveAssertLong(JtxICalObject.DTEND, sample?.dtend, Component.VJOURNAL.name)
+    @Test fun check_DTEND_TIMEZONE() = insertRetrieveAssertString(JtxICalObject.DTEND_TIMEZONE, sample?.dtendTimezone, Component.VJOURNAL.name)
+    @Test fun check_STATUS() = insertRetrieveAssertString(JtxICalObject.STATUS, sample?.status, Component.VJOURNAL.name)
+    @Test fun check_CLASSIFICATION() = insertRetrieveAssertString(JtxICalObject.CLASSIFICATION, sample?.classification, Component.VJOURNAL.name)
+    @Test fun check_URL() = insertRetrieveAssertString(JtxICalObject.URL, sample?.url, Component.VJOURNAL.name)
+    @Test fun check_CONTACT() = insertRetrieveAssertString(JtxICalObject.CONTACT, sample?.contact, Component.VJOURNAL.name)
+    @Test fun check_GEO_LAT() = insertRetrieveAssertDouble(JtxICalObject.GEO_LAT, sample?.geoLat, Component.VJOURNAL.name)
+    @Test fun check_GEO_LONG() = insertRetrieveAssertDouble(JtxICalObject.GEO_LONG, sample?.geoLong, Component.VJOURNAL.name)
+    @Test fun check_LOCATION() = insertRetrieveAssertString(JtxICalObject.LOCATION, sample?.location, Component.VJOURNAL.name)
+    @Test fun check_LOCATION_ALTREP() = insertRetrieveAssertString(JtxICalObject.LOCATION_ALTREP, sample?.locationAltrep, Component.VJOURNAL.name)
+    @Test fun check_PERCENT() = insertRetrieveAssertInt(JtxICalObject.PERCENT, sample?.percent, Component.VJOURNAL.name)
+    @Test fun check_PRIORITY() = insertRetrieveAssertInt(JtxICalObject.PRIORITY, sample?.priority, Component.VJOURNAL.name)
+    @Test fun check_DUE() = insertRetrieveAssertLong(JtxICalObject.DUE, sample?.due, Component.VJOURNAL.name)
+    @Test fun check_DUE_TIMEZONE() = insertRetrieveAssertString(JtxICalObject.DUE_TIMEZONE, sample?.dueTimezone, Component.VJOURNAL.name)
+    @Test fun check_COMPLETED() = insertRetrieveAssertLong(JtxICalObject.COMPLETED, sample?.completed, Component.VJOURNAL.name)
+    @Test fun check_COMPLETED_TIMEZONE() = insertRetrieveAssertString(JtxICalObject.COMPLETED_TIMEZONE, sample?.completedTimezone, Component.VJOURNAL.name)
+    @Test fun check_DURATION() = insertRetrieveAssertString(JtxICalObject.DURATION, sample?.duration, Component.VJOURNAL.name)
+    @Test fun check_RRULE() = insertRetrieveAssertString(JtxICalObject.RRULE, sample?.rrule, Component.VJOURNAL.name)
+    @Test fun check_RDATE() = insertRetrieveAssertString(JtxICalObject.RDATE, sample?.rdate, Component.VJOURNAL.name)
+    @Test fun check_EXDATE() = insertRetrieveAssertString(JtxICalObject.EXDATE, sample?.exdate, Component.VJOURNAL.name)
+    @Test fun check_RECURID() = insertRetrieveAssertString(JtxICalObject.RECURID, sample?.recurid, Component.VJOURNAL.name)
+    @Test fun check_UID() = insertRetrieveAssertString(JtxICalObject.UID, sample?.uid, Component.VJOURNAL.name)
+    @Test fun check_CREATED() = insertRetrieveAssertLong(JtxICalObject.CREATED, sample?.created, Component.VJOURNAL.name)
+    @Test fun check_DTSTAMP() = insertRetrieveAssertLong(JtxICalObject.DTSTAMP, sample?.dtstamp, Component.VJOURNAL.name)
+    @Test fun check_LAST_MODIFIED() = insertRetrieveAssertLong(JtxICalObject.LAST_MODIFIED, sample?.lastModified, Component.VJOURNAL.name)
+    @Test fun check_SEQUENCE() = insertRetrieveAssertLong(JtxICalObject.SEQUENCE, sample?.sequence, Component.VJOURNAL.name)
+    @Test fun check_COLOR() = insertRetrieveAssertInt(JtxICalObject.COLOR, sample?.color, Component.VJOURNAL.name)
+    @Test fun check_DIRTY() = insertRetrieveAssertBoolean(JtxICalObject.DIRTY, sample?.dirty, Component.VJOURNAL.name)
+    @Test fun check_DELETED() = insertRetrieveAssertBoolean(JtxICalObject.DELETED,sample?.deleted, Component.VJOURNAL.name)
+    @Test fun check_FILENAME() = insertRetrieveAssertString(JtxICalObject.FILENAME, sample?.fileName, Component.VJOURNAL.name)
+    @Test fun check_ETAG() = insertRetrieveAssertString(JtxICalObject.ETAG, sample?.eTag, Component.VJOURNAL.name)
+    @Test fun check_SCHEDULETAG() = insertRetrieveAssertString(JtxICalObject.SCHEDULETAG, sample?.scheduleTag, Component.VJOURNAL.name)
+    @Test fun check_FLAGS() = insertRetrieveAssertInt(JtxICalObject.FLAGS, sample?.flags, Component.VJOURNAL.name)
+
+
+    private fun insertRetrieveAssertString(field: String, fieldContent: String?, component: String) {
+
+        assertNotNull(fieldContent)    // fieldContent should not be null, check if the testcase was built correctly
+
+        val cv = ContentValues().apply {
+            put(field, fieldContent)
+            put(JtxICalObject.COMPONENT, component)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        client.query(uri, null, null, null, null)?.use {
+            val itemCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, itemCV)
+            assertEquals(fieldContent, itemCV.getAsString(field))
+        }
+    }
+
+    private fun insertRetrieveAssertBoolean(field: String, fieldContent: Boolean?, component: String) {
+
+        assertNotNull(fieldContent)    // fieldContent should not be null, check if the testcase was built correctly
+
+        val cv = ContentValues().apply {
+            put(field, fieldContent)
+            put(JtxICalObject.COMPONENT, component)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        client.query(uri, null, null, null, null)?.use {
+            val itemCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, itemCV)
+            assertEquals(fieldContent, itemCV.getAsBoolean(field))
+        }
+    }
+
+    private fun insertRetrieveAssertLong(field: String, fieldContent: Long?, component: String) {
+
+        assertNotNull(fieldContent)    // fieldContent should not be null, check if the testcase was built correctly
+
+        val cv = ContentValues().apply {
+            put(field, fieldContent)
+            put(JtxICalObject.COMPONENT, component)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        client.query(uri, null, null, null, null)?.use {
+            val itemCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, itemCV)
+            assertEquals(fieldContent, itemCV.getAsLong(field))
+        }
+    }
+
+    private fun insertRetrieveAssertInt(field: String, fieldContent: Int?, component: String) {
+
+        assertNotNull(fieldContent)    // fieldContent should not be null, check if the testcase was built correctly
+
+        val cv = ContentValues().apply {
+            put(field, fieldContent)
+            put(JtxICalObject.COMPONENT, component)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        client.query(uri, null, null, null, null)?.use {
+            val itemCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, itemCV)
+            assertEquals(fieldContent, itemCV.getAsInteger(field))
+        }
+    }
+
+    private fun insertRetrieveAssertDouble(field: String, fieldContent: Double?, component: String) {
+
+        assertNotNull(fieldContent)    // fieldContent should not be null, check if the testcase was built correctly
+
+        val cv = ContentValues().apply {
+            put(field, fieldContent)
+            put(JtxICalObject.COMPONENT, component)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        client.query(uri, null, null, null, null)?.use {
+            val itemCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, itemCV)
+            assertEquals(fieldContent, itemCV.getAsDouble(field))
+        }
+    }
+
+    @Test
+    fun assertComment() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val comment = at.bitfire.ical4android.JtxICalObject.Comment(
+            text = "comment",
+            altrep = "Kommentar",
+            language = "de",
+            other = "X-OTHER:Test"
+        )
+
+        val commentCV = ContentValues().apply {
+            put(JtxContract.JtxComment.TEXT, comment.text)
+            put(JtxContract.JtxComment.ALTREP, comment.altrep)
+            put(JtxContract.JtxComment.LANGUAGE, comment.language)
+            put(JtxContract.JtxComment.OTHER, comment.other)
+            put(JtxContract.JtxComment.ICALOBJECT_ID, id)
+        }
+
+        val commentUri = client.insert(JtxContract.JtxComment.CONTENT_URI.asSyncAdapter(testAccount), commentCV)!!
+        client.query(commentUri, null, null, null, null)?.use {
+            val retrievedCommentCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedCommentCV)
+            assertEquals(comment.text, retrievedCommentCV.getAsString(JtxContract.JtxComment.TEXT))
+            assertEquals(comment.altrep, retrievedCommentCV.getAsString(JtxContract.JtxComment.ALTREP))
+            assertEquals(comment.language, retrievedCommentCV.getAsString(JtxContract.JtxComment.LANGUAGE))
+            assertEquals(comment.other, retrievedCommentCV.getAsString(JtxContract.JtxComment.OTHER))
+        }
+    }
+
+    @Test
+    fun assertResource() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val resource = at.bitfire.ical4android.JtxICalObject.Resource(
+            text = "projector",
+            altrep = "Projektor",
+            language = "de",
+            other = "X-OTHER:Test"
+        )
+
+        val resourceCV = ContentValues().apply {
+            put(JtxContract.JtxResource.TEXT, resource.text)
+            put(JtxContract.JtxResource.LANGUAGE, resource.language)
+            put(JtxContract.JtxResource.OTHER, resource.other)
+            put(JtxContract.JtxResource.ICALOBJECT_ID, id)
+        }
+
+        val resourceUri = client.insert(JtxContract.JtxResource.CONTENT_URI.asSyncAdapter(testAccount), resourceCV)!!
+        client.query(resourceUri, null, null, null, null)?.use {
+            val retrievedResourceCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedResourceCV)
+            assertEquals(resource.text, retrievedResourceCV.getAsString(JtxContract.JtxResource.TEXT))
+            assertEquals(resource.language, retrievedResourceCV.getAsString(JtxContract.JtxResource.LANGUAGE))
+            assertEquals(resource.other, retrievedResourceCV.getAsString(JtxContract.JtxResource.OTHER))
+        }
+    }
+
+    @Test
+    fun assertAttendee() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val attendee = at.bitfire.ical4android.JtxICalObject.Attendee(
+            caladdress = "jtx@techbee.at",
+            cutype = JtxContract.JtxAttendee.Cutype.INDIVIDUAL.name,
+            member = "group",
+            partstat = "0",
+            role = JtxContract.JtxAttendee.Role.`REQ-PARTICIPANT`.name,
+            rsvp = false,
+            delegatedfrom = "jtx@techbee.at",
+            delegatedto = "jtx@techbee.at",
+            sentby = "jtx@techbee.at",
+            cn = "jtx Board",
+            dir = "dir",
+            language = "de",
+            other = "X-OTHER:Test"
+        )
+
+        val attendeeCV = ContentValues().apply {
+            put(JtxContract.JtxAttendee.CALADDRESS, attendee.caladdress)
+            put(JtxContract.JtxAttendee.CUTYPE, attendee.cutype)
+            put(JtxContract.JtxAttendee.MEMBER, attendee.member)
+            put(JtxContract.JtxAttendee.PARTSTAT, attendee.partstat)
+            put(JtxContract.JtxAttendee.ROLE, attendee.role)
+            put(JtxContract.JtxAttendee.RSVP, attendee.rsvp)
+            put(JtxContract.JtxAttendee.DELEGATEDFROM, attendee.delegatedfrom)
+            put(JtxContract.JtxAttendee.DELEGATEDTO, attendee.delegatedto)
+            put(JtxContract.JtxAttendee.SENTBY, attendee.sentby)
+            put(JtxContract.JtxAttendee.CN, attendee.cn)
+            put(JtxContract.JtxAttendee.DIR, attendee.dir)
+            put(JtxContract.JtxAttendee.LANGUAGE, attendee.language)
+            put(JtxContract.JtxAttendee.OTHER, attendee.other)
+            put(JtxContract.JtxAttendee.ICALOBJECT_ID, id)
+        }
+
+        val attendeeUri = client.insert(JtxContract.JtxAttendee.CONTENT_URI.asSyncAdapter(testAccount), attendeeCV)!!
+        client.query(attendeeUri, null, null, null, null)?.use {
+            val retrievedAttendeeCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAttendeeCV)
+            assertEquals(attendee.caladdress, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.CALADDRESS))
+            assertEquals(attendee.cutype, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.CUTYPE))
+            assertEquals(attendee.member, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.MEMBER))
+            assertEquals(attendee.partstat, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.PARTSTAT))
+            assertEquals(attendee.role, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.ROLE))
+            assertEquals(attendee.rsvp, retrievedAttendeeCV.getAsBoolean(JtxContract.JtxAttendee.RSVP))
+            assertEquals(attendee.delegatedfrom, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.DELEGATEDFROM))
+            assertEquals(attendee.delegatedto, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.DELEGATEDTO))
+            assertEquals(attendee.sentby, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.SENTBY))
+            assertEquals(attendee.cn, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.CN))
+            assertEquals(attendee.dir, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.DIR))
+            assertEquals(attendee.language, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.LANGUAGE))
+            assertEquals(attendee.other, retrievedAttendeeCV.getAsString(JtxContract.JtxAttendee.OTHER))
+        }
+    }
+
+    @Test
+    fun assertCategory() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val category = at.bitfire.ical4android.JtxICalObject.Category(
+            text = "projector",
+        )
+
+        val categoryCV = ContentValues().apply {
+            put(JtxContract.JtxCategory.TEXT, category.text)
+            put(JtxContract.JtxCategory.ICALOBJECT_ID, id)
+        }
+
+        val categoryUri = client.insert(JtxContract.JtxCategory.CONTENT_URI.asSyncAdapter(testAccount), categoryCV)!!
+        client.query(categoryUri, null, null, null, null)?.use {
+            val retrievedCategoryCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedCategoryCV)
+            assertEquals(category.text, retrievedCategoryCV.getAsString(JtxContract.JtxCategory.TEXT))
+        }
+    }
+
+    @Test
+    fun assertAttachment_without_binary() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val attachment = at.bitfire.ical4android.JtxICalObject.Attachment(
+            uri = "https://jtx.techbee.at/sample.pdf",
+            fmttype = "application/pdf",
+            other = "X-OTHER:other",
+        )
+
+        val attachmentCV = ContentValues().apply {
+            put(JtxContract.JtxAttachment.URI, attachment.uri)
+            put(JtxContract.JtxAttachment.FMTTYPE, attachment.fmttype)
+            put(JtxContract.JtxAttachment.OTHER, attachment.other)
+            put(JtxContract.JtxAttachment.ICALOBJECT_ID, id)
+        }
+
+        val attachmentUri = client.insert(JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(testAccount), attachmentCV)!!
+        client.query(attachmentUri, null, null, null, null)?.use {
+            val retrievedAttachmentCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAttachmentCV)
+            assertEquals(attachment.uri, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.URI))
+            assertEquals(attachment.fmttype, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.FMTTYPE))
+            assertEquals(attachment.other, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.OTHER))
+        }
+    }
+
+
+    @Test
+    fun assertAttachment_without_binary_and_uri() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val attachment = at.bitfire.ical4android.JtxICalObject.Attachment(
+            fmttype = "application/pdf"
+        )
+
+        val attachmentCV = ContentValues().apply {
+            put(JtxContract.JtxAttachment.FMTTYPE, attachment.fmttype)
+            put(JtxContract.JtxAttachment.ICALOBJECT_ID, id)
+        }
+
+        val attachmentUri = client.insert(JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(testAccount), attachmentCV)!!
+        client.query(attachmentUri, null, null, null, null)?.use {
+            val retrievedAttachmentCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAttachmentCV)
+            assertEquals(attachment.fmttype, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.FMTTYPE))
+            assertNotNull(retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.URI))
+        }
+
+        val textIn = "jtx Board rulz"
+        val pfd = client.openFile(attachmentUri, "w", null)
+        ParcelFileDescriptor.AutoCloseOutputStream(pfd).write(textIn.toByteArray())
+
+        val pfd2 = client.openFile(attachmentUri, "r", null)
+        val textCompare = String(ParcelFileDescriptor.AutoCloseInputStream(pfd2).readBytes())
+
+        Assert.assertEquals(textIn, textCompare)
+
+    }
+
+    @Test
+    fun assertAttachment_with_binary() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val attachment = at.bitfire.ical4android.JtxICalObject.Attachment(
+            //uri = "https://jtx.techbee.at/sample.pdf",
+            binary = "anR4IEJvYXJk",
+            fmttype = "application/pdf",
+            other = "X-OTHER:other",
+        )
+
+        val attachmentCV = ContentValues().apply {
+            //put(JtxContract.JtxAttachment.URI, attachment.uri)
+            put(JtxContract.JtxAttachment.BINARY, attachment.binary)
+            put(JtxContract.JtxAttachment.FMTTYPE, attachment.fmttype)
+            put(JtxContract.JtxAttachment.OTHER, attachment.other)
+            put(JtxContract.JtxAttachment.ICALOBJECT_ID, id)
+        }
+
+        val attachmentUri = client.insert(JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(testAccount), attachmentCV)!!
+        client.query(attachmentUri, null, null, null, null)?.use {
+            val retrievedAttachmentCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAttachmentCV)
+            assertTrue(retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.URI).startsWith("content://"))   // binary was replaced by content uri
+            assertNull(retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.BINARY))
+            assertEquals(attachment.fmttype, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.FMTTYPE))
+            assertEquals(attachment.other, retrievedAttachmentCV.getAsString(JtxContract.JtxAttachment.OTHER))
+        }
+    }
+
+    @Test
+    fun assertRelatedto() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val relatedto = at.bitfire.ical4android.JtxICalObject.RelatedTo(
+            text = "1635164243187-3fd0f89e-d017-471e-a046-71ff1844d58e@at.techbee.jtx",
+            reltype = JtxContract.JtxRelatedto.Reltype.CHILD.name,
+            other = "X-OTHER: other"
+        )
+
+        val relatedtoCV = ContentValues().apply {
+            put(JtxContract.JtxRelatedto.TEXT, relatedto.text)
+            put(JtxContract.JtxRelatedto.RELTYPE, relatedto.reltype)
+            put(JtxContract.JtxRelatedto.OTHER, relatedto.other)
+            put(JtxContract.JtxRelatedto.ICALOBJECT_ID, id)
+        }
+
+        val relatedtoUri = client.insert(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(testAccount), relatedtoCV)!!
+        client.query(relatedtoUri, null, null, null, null)?.use {
+            val retrievedRelatedtoCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedRelatedtoCV)
+            assertEquals(relatedto.text, retrievedRelatedtoCV.getAsString(JtxContract.JtxRelatedto.TEXT))
+            assertEquals(relatedto.reltype, retrievedRelatedtoCV.getAsString(JtxContract.JtxRelatedto.RELTYPE))
+            assertEquals(relatedto.other, retrievedRelatedtoCV.getAsString(JtxContract.JtxRelatedto.OTHER))
+        }
+    }
+
+    @Test
+    fun assertAlarm_basic() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val alarm = at.bitfire.ical4android.JtxICalObject.Alarm(
+            action = JtxContract.JtxAlarm.AlarmAction.AUDIO.name,
+            description = "desc",
+            summary = "summary",
+            duration = "PT15M",
+            triggerTime = 1641557428506L,
+            repeat = "4",
+            attach = "ftp://example.com/pub/sounds/bell-01.aud",
+            other = "X-OTHER: other",
+            )
+
+        val alarmCV = ContentValues().apply {
+            put(JtxContract.JtxAlarm.ACTION, alarm.action)
+            put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+            put(JtxContract.JtxAlarm.SUMMARY, alarm.summary)
+            put(JtxContract.JtxAlarm.DURATION, alarm.duration)
+            put(JtxContract.JtxAlarm.TRIGGER_TIME, alarm.triggerTime)
+            put(JtxContract.JtxAlarm.REPEAT, alarm.repeat)
+            put(JtxContract.JtxAlarm.ATTACH, alarm.attach)
+            put(JtxContract.JtxAlarm.OTHER, alarm.other)
+            put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+        }
+
+        val alarmUri = client.insert(JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(testAccount), alarmCV)!!
+        client.query(alarmUri, null, null, null, null)?.use {
+            val retrievedAlarmCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAlarmCV)
+            assertEquals(alarm.action, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ACTION))
+            assertEquals(alarm.description, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DESCRIPTION))
+            assertEquals(alarm.summary, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.SUMMARY))
+            assertEquals(alarm.duration, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DURATION))
+            assertEquals(alarm.repeat, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.REPEAT))
+            assertEquals(alarm.attach, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ATTACH))
+            assertEquals(alarm.other, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.OTHER))
+        }
+    }
+
+
+    @Test
+    fun assertAlarm_trigger_duration() {
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VTODO.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val alarm = at.bitfire.ical4android.JtxICalObject.Alarm(
+            action = JtxContract.JtxAlarm.AlarmAction.DISPLAY.name,
+            description = "desc",
+            triggerRelativeDuration = "-PT5M",
+            triggerRelativeTo = JtxContract.JtxAlarm.AlarmRelativeTo.START.name
+        )
+
+        val alarmCV = ContentValues().apply {
+            put(JtxContract.JtxAlarm.ACTION, alarm.action)
+            put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+            put(JtxContract.JtxAlarm.TRIGGER_RELATIVE_DURATION, alarm.triggerRelativeDuration)
+            put(JtxContract.JtxAlarm.TRIGGER_RELATIVE_TO, alarm.triggerRelativeTo)
+            put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+        }
+
+        val alarmUri = client.insert(JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(testAccount), alarmCV)!!
+        client.query(alarmUri, null, null, null, null)?.use {
+            val retrievedAlarmCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAlarmCV)
+            assertEquals(alarm.action, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ACTION))
+            assertEquals(alarm.description, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DESCRIPTION))
+            assertEquals(alarm.triggerRelativeTo, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.TRIGGER_RELATIVE_TO))
+            assertEquals(alarm.triggerRelativeDuration, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.TRIGGER_RELATIVE_DURATION))
+        }
+    }
+
+    @Test
+    fun assertAlarm_trigger_time_withoutTZ() {
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VTODO.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val alarm = at.bitfire.ical4android.JtxICalObject.Alarm(
+            action = JtxContract.JtxAlarm.AlarmAction.DISPLAY.name,
+            description = "desc",
+            triggerTime = 1641557428506L
+        )
+
+        val alarmCV = ContentValues().apply {
+            put(JtxContract.JtxAlarm.ACTION, alarm.action)
+            put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+            put(JtxContract.JtxAlarm.TRIGGER_TIME, alarm.triggerTime)
+            put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+        }
+
+        val alarmUri = client.insert(JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(testAccount), alarmCV)!!
+        client.query(alarmUri, null, null, null, null)?.use {
+            val retrievedAlarmCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAlarmCV)
+            assertEquals(alarm.action, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ACTION))
+            assertEquals(alarm.description, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DESCRIPTION))
+            assertEquals(alarm.triggerTime, retrievedAlarmCV.getAsLong(JtxContract.JtxAlarm.TRIGGER_TIME))
+        }
+    }
+
+    @Test
+    fun assertAlarm_trigger_time_UTC() {
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VTODO.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val alarm = at.bitfire.ical4android.JtxICalObject.Alarm(
+            action = JtxContract.JtxAlarm.AlarmAction.DISPLAY.name,
+            description = "desc",
+            triggerTime = 1641557428506L,
+            triggerTimezone = "UTC"
+        )
+
+        val alarmCV = ContentValues().apply {
+            put(JtxContract.JtxAlarm.ACTION, alarm.action)
+            put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+            put(JtxContract.JtxAlarm.TRIGGER_TIME, alarm.triggerTime)
+            put(JtxContract.JtxAlarm.TRIGGER_TIMEZONE, alarm.triggerTimezone)
+            put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+        }
+
+        val alarmUri = client.insert(JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(testAccount), alarmCV)!!
+        client.query(alarmUri, null, null, null, null)?.use {
+            val retrievedAlarmCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAlarmCV)
+            assertEquals(alarm.action, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ACTION))
+            assertEquals(alarm.description, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DESCRIPTION))
+            assertEquals(alarm.triggerTime, retrievedAlarmCV.getAsLong(JtxContract.JtxAlarm.TRIGGER_TIME))
+            assertEquals(alarm.triggerTimezone, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.TRIGGER_TIMEZONE))
+        }
+    }
+
+
+    @Test
+    fun assertAlarm_trigger_time_Vienna() {
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VTODO.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val alarm = at.bitfire.ical4android.JtxICalObject.Alarm(
+            action = "DISPLAY",
+            description = "desc",
+            triggerTime = 1641557428506L,
+            triggerTimezone = "Europe/Vienna"
+        )
+
+        val alarmCV = ContentValues().apply {
+            put(JtxContract.JtxAlarm.ACTION, alarm.action)
+            put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+            put(JtxContract.JtxAlarm.TRIGGER_TIME, alarm.triggerTime)
+            put(JtxContract.JtxAlarm.TRIGGER_TIMEZONE, alarm.triggerTimezone)
+            put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+        }
+
+        val alarmUri = client.insert(JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(testAccount), alarmCV)!!
+        client.query(alarmUri, null, null, null, null)?.use {
+            val retrievedAlarmCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedAlarmCV)
+            assertEquals(alarm.action, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.ACTION))
+            assertEquals(alarm.description, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.DESCRIPTION))
+            assertEquals(alarm.triggerTime, retrievedAlarmCV.getAsLong(JtxContract.JtxAlarm.TRIGGER_TIME))
+            assertEquals(alarm.triggerTimezone, retrievedAlarmCV.getAsString(JtxContract.JtxAlarm.TRIGGER_TIMEZONE))
+        }
+    }
+
+
+    @Test
+    fun assertUnknown() {
+
+        val cv = ContentValues().apply {
+            put(JtxICalObject.COMPONENT, Component.VJOURNAL.name)
+            put(JtxICalObject.ICALOBJECT_COLLECTIONID, collection?.id)
+        }
+        val uri = client.insert(JtxICalObject.CONTENT_URI.asSyncAdapter(testAccount), cv)!!
+        val id = uri.lastPathSegment
+
+        val unknown = at.bitfire.ical4android.JtxICalObject.Unknown(
+            value = "X-PROP:my value"
+        )
+
+        val unknownCV = ContentValues().apply {
+            put(JtxContract.JtxUnknown.UNKNOWN_VALUE, unknown.value)
+            put(JtxContract.JtxUnknown.ICALOBJECT_ID, id)
+        }
+
+        val unknownUri = client.insert(JtxContract.JtxUnknown.CONTENT_URI.asSyncAdapter(testAccount), unknownCV)!!
+        client.query(unknownUri, null, null, null, null)?.use {
+            val retrievedUnknownCV = ContentValues()
+            it.moveToFirst()
+            DatabaseUtils.cursorRowToContentValues(it, retrievedUnknownCV)
+            assertEquals(unknown.value, retrievedUnknownCV.getAsString(JtxContract.JtxUnknown.UNKNOWN_VALUE))
+        }
+    }
+
+
+
+
+    /** TESTS TO READ A FILE; INSERT IT IN THE CONTENT PROVIDER; READ THE CONTENT PROVIDER AND THEN COMPARE IF THE CONTENT OF THE GENERATED ICAL IS STILL THE SAME AS FROM THE SERVER */
+
+    // VTODO
+    @Test fun check_input_equals_output_vtodo_most_fields1() = compare_properties("jtx/vtodo/most-fields1.ics", listOf("EXDATE", "RDATE"))
+    @Test fun check_input_equals_output_vtodo_most_fields2() = compare_properties("jtx/vtodo/most-fields2.ics", null)
+    @Test fun check_input_equals_output_vtodo_utf8() = compare_properties("jtx/vtodo/utf8.ics", null)
+    @Test fun check_input_equals_output_vtodo_rfc5545_sample() = compare_properties("jtx/vtodo/rfc5545-sample1.ics", null)
+    @Test fun check_input_equals_output_vtodo_empty_priority() = compare_properties("jtx/vtodo/empty-priority.ics", null)
+    @Test fun check_input_equals_output_vtodo_latin1() = compare_properties("jtx/vtodo/latin1.ics", null)
+
+    // VJOURNAL
+    @Test fun check_input_equals_output_vjournal_default_example() = compare_properties("jtx/vjournal/default-example.ics", null)
+    @Test fun check_input_equals_output_vjournal_default_example_note() = compare_properties("jtx/vjournal/default-example-note.ics", null)
+    @Test fun check_input_equals_output_vjournal_utf8() = compare_properties("jtx/vjournal/utf8.ics", null)
+    @Test fun check_input_equals_output_vjournal_two_line() = compare_properties("jtx/vjournal/two-line-description-without-crlf.ics", listOf("CREATED", "LAST-MODIFIED", "DTSTART"))   // expected:<CREATED;VALUE=DATE-TIME:20131008T205713Z > but was:<CREATED:20131008T205713Z  is ignored here; expected:<LAST-MODIFIED;VALUE=DATE-TIME:20131008T205740> but was:<LAST-MODIFIED:20131008T205740Z  is ignored here as the actual is the correct result
+    //@Test fun check_input_equals_output_vjournal_two_journals() = compare_properties("jtx/vjournal/two-events-without-exceptions.ics", null) // this file contains two events, the direct comparison through the given method would not work
+    @Test fun check_input_equals_output_vjournal_recurring() = compare_properties("jtx/vjournal/recurring.ics", null)
+    //@Test fun check_input_equals_output_vjournal_outlook_theoretical() = compare_properties("jtx/vjournal/outlook-theoretical.ics", null)    // includes custom timezones, ignored for now
+    @Test fun check_input_equals_output_vjournal_outlook_theoretical2() = compare_properties("jtx/vjournal/outlook-theoretical2.ics", null)
+    @Test fun check_input_equals_output_vjournal_latin1() = compare_properties("jtx/vjournal/latin1.ics", null)
+    @Test fun check_input_equals_output_vjournal_journalonthatday() = compare_properties("jtx/vjournal/journal-on-that-day.ics", null)
+    //@Test fun check_input_equals_output_vjournal_dst_only_vtimezone() = compare_properties("jtx/vjournal/dst-only-vtimezone.ics", null)    // includes custom timezones, ignored for now
+    @Test fun check_input_equals_output_vjournal_all_day() = compare_properties("jtx/vjournal/all-day.ics", null)
+
+    /**
+     * This function takes a file asserts if the ICalendar is the same before and after processing with getIncomingIcal and getOutgoingIcal
+     * @param filename the filename to be processed
+     * @param exceptions a list of property names that should not cause the assertion to fail (DTSTAMP is taken in any case)
+     */
+    private fun compare_properties(filename: String, exceptions: List<String>?) {
+
+        val iCalIn = getIncomingIcal(filename)
+        val iCalOut = getOutgoingIcal(filename)
+
+        //assertEquals(iCalIn.components[0].getProperty(Component.VTODO), iCalOut.components[0].getProperty(Component.VTODO))
+
+        // there should only be one component for VJOURNAL and VTODO!
+        for(i in 0 until iCalIn.components.size)  {
+
+            iCalIn.components[i].properties.forEach { inProp ->
+
+                if(inProp.name == "DTSTAMP" || exceptions?.contains(inProp.name) == true)
+                    return@forEach
+                val outProp = iCalOut.components[i].properties.getProperty<Property>(inProp.name)
+                assertEquals(inProp, outProp)
+            }
+        }
+    }
+
+
+    /**
+     * This function takes a file and returns the parsed ical4j Calendar object
+     * @param filename: The filename of the ics-file
+     * @return the ICalendar with the parsed information from the file
+     */
+    private fun getIncomingIcal(filename: String): Calendar {
+
+        val stream = javaClass.classLoader!!.getResourceAsStream(filename)
+        val reader = InputStreamReader(stream, Charsets.UTF_8)
+
+        val iCalIn = ICalendar.fromReader(reader)
+
+        stream.close()
+        reader.close()
+
+        return iCalIn
+    }
+
+    /**
+     * This function takes a filename and creates a JtxICalObject.
+     * Then it uses the object to create an ical4j Calendar again.
+     * @param filename: The filename of the ics-file
+     * @return The ICalendar after applying all functionalities of JtxICalObject.fromReader(...)
+     */
+    private fun getOutgoingIcal(filename: String): Calendar {
+
+        val stream = javaClass.classLoader!!.getResourceAsStream(filename)
+        val reader = InputStreamReader(stream, Charsets.UTF_8)
+        val iCalObject = at.bitfire.ical4android.JtxICalObject.fromReader(reader, collection!!)
+
+        val os = ByteArrayOutputStream()
+
+        iCalObject[0].write(os)
+
+        val iCalOut = ICalendar.fromReader(os.toByteArray().inputStream().reader())
+
+        stream.close()
+        reader.close()
+
+        return iCalOut
+    }
+}
diff --git a/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt b/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
index a8c33b4..81f0783 100644
--- a/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.model.property.TzOffsetFrom
diff --git a/src/androidTest/java/at/bitfire/ical4android/MiscUtilsAndroidTest.kt b/src/androidTest/java/at/bitfire/ical4android/MiscUtilsAndroidTest.kt
index 5c51c94..67016e1 100644
--- a/src/androidTest/java/at/bitfire/ical4android/MiscUtilsAndroidTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/MiscUtilsAndroidTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/TestUtils.kt b/src/androidTest/java/at/bitfire/ical4android/TestUtils.kt
index 57bbd94..3387920 100644
--- a/src/androidTest/java/at/bitfire/ical4android/TestUtils.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/TestUtils.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/UnknownPropertyTest.kt b/src/androidTest/java/at/bitfire/ical4android/UnknownPropertyTest.kt
index 6ba223c..b4a8be5 100644
--- a/src/androidTest/java/at/bitfire/ical4android/UnknownPropertyTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/UnknownPropertyTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import androidx.test.filters.SmallTest
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestCalendar.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestCalendar.kt
index e127ec6..19d37cb 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestCalendar.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestCalendar.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android.impl
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
index 3fd19c9..f9c9571 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android.impl
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxCollection.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxCollection.kt
new file mode 100644
index 0000000..5a69060
--- /dev/null
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxCollection.kt
@@ -0,0 +1,51 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android.impl
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import at.bitfire.ical4android.JtxCollection
+import at.bitfire.ical4android.JtxCollectionFactory
+import at.bitfire.ical4android.JtxICalObject
+import at.bitfire.ical4android.MiscUtils.CursorHelper.toValues
+import at.techbee.jtx.JtxContract
+import java.util.*
+
+class TestJtxCollection(
+        account: Account,
+        provider: ContentProviderClient,
+        id: Long
+): JtxCollection<JtxICalObject>(account, provider, TestJtxIcalObject.Factory, id) {
+
+    /**
+     * Queries [JtxContract.JtxICalObject] from this collection. Adds a WHERE clause that restricts the
+     * query to [JtxContract.JtxCollection.ID] = [id].
+     * @param _where selection
+     * @param _whereArgs arguments for selection
+     * @return events from this calendar which match the selection
+     */
+    fun queryICalObjects(_where: String? = null, _whereArgs: Array<String>? = null): List<JtxICalObject> {
+        val where = "(${_where ?: "1"}) AND ${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ?"
+        val whereArgs = (_whereArgs ?: arrayOf()) + id.toString()
+
+        val iCalObjects = LinkedList<JtxICalObject>()
+        client.query(jtxSyncURI(), null, where, whereArgs, null)?.use { cursor ->
+            while (cursor.moveToNext())
+                iCalObjects += TestJtxIcalObject.Factory.fromProvider(this, cursor.toValues())
+        }
+        return iCalObjects
+    }
+
+
+    object Factory: JtxCollectionFactory<TestJtxCollection> {
+
+        override fun newInstance(
+            account: Account,
+            client: ContentProviderClient,
+            id: Long
+        ): TestJtxCollection = TestJtxCollection(account, client, id)
+    }
+
+}
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt
new file mode 100644
index 0000000..57615fb
--- /dev/null
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt
@@ -0,0 +1,19 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android.impl
+
+import android.content.ContentValues
+import at.bitfire.ical4android.*
+
+class TestJtxIcalObject(testCollection: JtxCollection<JtxICalObject>): JtxICalObject(testCollection) {
+
+    object Factory: JtxICalObjectFactory<JtxICalObject> {
+
+        override fun fromProvider(
+            collection: JtxCollection<JtxICalObject>,
+            values: ContentValues
+        ): JtxICalObject = TestJtxIcalObject(collection)
+    }
+}
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestTask.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestTask.kt
index ddb2d66..6c03dab 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestTask.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestTask.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android.impl
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestTaskList.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestTaskList.kt
index 6ae8479..0f4ef1e 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestTaskList.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestTaskList.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android.impl
 
diff --git a/src/androidTest/resources/jtx/vjournal/all-day.ics b/src/androidTest/resources/jtx/vjournal/all-day.ics
new file mode 100644
index 0000000..1300862
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/all-day.ics
@@ -0,0 +1,10 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//hacksw/handcal//NONSGML v1.0//EN
+BEGIN:VJOURNAL
+UID:all-day-1day@example.com
+DTSTAMP:20140101T000000Z
+DTSTART;VALUE=DATE:19970714
+SUMMARY:All-Day 1 Day
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/default-example-note.ics b/src/androidTest/resources/jtx/vjournal/default-example-note.ics
new file mode 100644
index 0000000..054cf68
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/default-example-note.ics
@@ -0,0 +1,18 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//hacksw/handcal//NONSGML v1.0//EN
+BEGIN:VJOURNAL
+UID:19970901T130000Z-123405@example.com
+DTSTAMP:19970901T130000Z
+SUMMARY:Staff meeting minutes
+DESCRIPTION:1. Staff meeting: Participants include Joe\,
+  Lisa\, and Bob. Aurora project plans were reviewed.
+  There is currently no budget reserves for this project.
+  Lisa will escalate to management. Next meeting on Tuesday.\n
+ 2. Telephone Conference: ABC Corp. sales representative
+  called to discuss new printer. Promised to get us a demo by
+  Friday.\n3. Henry Miller (Handsoff Insurance): Car was
+  totaled by tree. Is looking into a loaner car. 555-2323
+  (tel).
+END:VJOURNAL
+END:VCALENDAR
\ No newline at end of file
diff --git a/src/androidTest/resources/jtx/vjournal/default-example.ics b/src/androidTest/resources/jtx/vjournal/default-example.ics
new file mode 100644
index 0000000..0a88565
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/default-example.ics
@@ -0,0 +1,19 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//hacksw/handcal//NONSGML v1.0//EN
+BEGIN:VJOURNAL
+UID:19970901T130000Z-123405@example.com
+DTSTAMP:19970901T130000Z
+DTSTART;VALUE=DATE:19970317
+SUMMARY:Staff meeting minutes
+DESCRIPTION:1. Staff meeting: Participants include Joe\,
+  Lisa\, and Bob. Aurora project plans were reviewed.
+  There is currently no budget reserves for this project.
+  Lisa will escalate to management. Next meeting on Tuesday.\n
+ 2. Telephone Conference: ABC Corp. sales representative
+  called to discuss new printer. Promised to get us a demo by
+  Friday.\n3. Henry Miller (Handsoff Insurance): Car was
+  totaled by tree. Is looking into a loaner car. 555-2323
+  (tel).
+END:VJOURNAL
+END:VCALENDAR
\ No newline at end of file
diff --git a/src/androidTest/resources/jtx/vjournal/dst-only-vtimezone.ics b/src/androidTest/resources/jtx/vjournal/dst-only-vtimezone.ics
new file mode 100644
index 0000000..e798232
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/dst-only-vtimezone.ics
@@ -0,0 +1,21 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+DTSTART:20180325T030000
+TZNAME:CEST
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VJOURNAL
+UID:only-dst@example.com
+DTSTAMP:20180329T084939Z
+DTSTART;TZID=Europe/Berlin:20180403T090000
+DTEND;TZID=Europe/Berlin:20180403T101500
+SUMMARY:Sample Event
+CREATED:20180329T084939Z
+LAST-MODIFIED:20180329T084939Z
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/journal-on-that-day.ics b/src/androidTest/resources/jtx/vjournal/journal-on-that-day.ics
new file mode 100644
index 0000000..20d8889
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/journal-on-that-day.ics
@@ -0,0 +1,11 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//hacksw/handcal//NONSGML v1.0//EN
+BEGIN:VJOURNAL
+UID:event-on-that-day@example.com
+DTSTAMP:19970714T170000Z
+ORGANIZER;CN=John Doe:MAILTO:john.doe@example.com
+DTSTART;VALUE=DATE:19970714
+SUMMARY:Bastille Day Party
+END:VJOURNAL
+END:VCALENDAR
\ No newline at end of file
diff --git a/src/androidTest/resources/jtx/vjournal/latin1.ics b/src/androidTest/resources/jtx/vjournal/latin1.ics
new file mode 100644
index 0000000..969b2bf
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/latin1.ics
@@ -0,0 +1,9 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VJOURNAL
+UID:latin1@ical4android.EventTest
+DTSTAMP:20150826T132300Z
+SUMMARY:����
+DTSTART:20131009T170000T
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/outlook-theoretical.ics b/src/androidTest/resources/jtx/vjournal/outlook-theoretical.ics
new file mode 100644
index 0000000..1f372bb
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/outlook-theoretical.ics
@@ -0,0 +1,71 @@
+BEGIN:VCALENDAR
+METHOD:PUBLISH
+PRODID:Microsoft Exchange Server 2010
+VERSION:2.0
+X-WR-CALNAME:Calendar
+BEGIN:VTIMEZONE
+TZID:China Standard Time
+BEGIN:STANDARD
+DTSTART:16010101T000000
+TZOFFSETFROM:+0800
+TZOFFSETTO:+0800
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:16010101T000000
+TZOFFSETFROM:+0800
+TZOFFSETTO:+0800
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VTIMEZONE
+TZID:W. Europe Standard Time
+BEGIN:STANDARD
+DTSTART:16010101T030000
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:16010101T020000
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VTIMEZONE
+TZID:India Standard Time
+BEGIN:STANDARD
+DTSTART:16010101T000000
+TZOFFSETFROM:+0530
+TZOFFSETTO:+0530
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:16010101T000000
+TZOFFSETFROM:+0530
+TZOFFSETTO:+0530
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VJOURNAL
+DESCRIPTION:\n.............................................................
+ .................................\n\n\n
+RRULE:FREQ=WEEKLY;UNTIL=20191218T080000Z;INTERVAL=1;BYDAY=WE;WKST=MO
+UID:040000008200E00074C5B7101A82E00800000000907682BE2B88D501000000000000000
+ 01000000077F6CDA3B634104B9BC1ED539119F558
+SUMMARY:Weekly Meeting - Test
+DTSTART;TZID=W. Europe Standard Time:20191023T090000
+CLASS:PUBLIC
+PRIORITY:5
+DTSTAMP:20191119T090349Z
+TRANSP:OPAQUE
+STATUS:DRAFT
+SEQUENCE:1
+LOCATION:Skype-Besprechung
+X-MICROSOFT-CDO-APPT-SEQUENCE:1
+X-MICROSOFT-CDO-BUSYSTATUS:BUSY
+X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
+X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
+X-MICROSOFT-CDO-IMPORTANCE:1
+X-MICROSOFT-CDO-INSTTYPE:1
+X-MICROSOFT-DONOTFORWARDMEETING:FALSE
+X-MICROSOFT-DISALLOW-COUNTER:FALSE
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/outlook-theoretical2.ics b/src/androidTest/resources/jtx/vjournal/outlook-theoretical2.ics
new file mode 100644
index 0000000..eea376d
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/outlook-theoretical2.ics
@@ -0,0 +1,29 @@
+BEGIN:VCALENDAR
+METHOD:PUBLISH
+PRODID:Microsoft Exchange Server 2010
+VERSION:2.0
+X-WR-CALNAME:Calendar
+BEGIN:VJOURNAL
+DESCRIPTION:\n.............................................................
+ .................................\n\n\n
+RRULE:FREQ=WEEKLY;UNTIL=20191218T080000Z;INTERVAL=1;BYDAY=WE;WKST=MO
+UID:040000008200E00074C5B7101A82E00800000000907682BE2B88D501000000000000000
+ 01000000077F6CDA3B634104B9BC1ED539119F558
+SUMMARY:Weekly Meeting - Test
+DTSTART:20191023T090000
+CLASS:PUBLIC
+DTSTAMP:20191119T090349Z
+TRANSP:OPAQUE
+STATUS:DRAFT
+SEQUENCE:1
+LOCATION:Skype-Besprechung
+X-MICROSOFT-CDO-APPT-SEQUENCE:1
+X-MICROSOFT-CDO-BUSYSTATUS:BUSY
+X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
+X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
+X-MICROSOFT-CDO-IMPORTANCE:1
+X-MICROSOFT-CDO-INSTTYPE:1
+X-MICROSOFT-DONOTFORWARDMEETING:FALSE
+X-MICROSOFT-DISALLOW-COUNTER:FALSE
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/recurring.ics b/src/androidTest/resources/jtx/vjournal/recurring.ics
new file mode 100644
index 0000000..c071186
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/recurring.ics
@@ -0,0 +1,9 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VJOURNAL
+UID:fcb42e4d-bc6e-4499-97f0-6616a02da7bc
+SUMMARY:Recurring event with one exception
+RRULE:FREQ=DAILY;COUNT=5
+DTSTART;VALUE=DATE:20150501
+END:VJOURNAL
+END:VCALENDAR
\ No newline at end of file
diff --git a/src/androidTest/resources/jtx/vjournal/two-events-without-exceptions.ics b/src/androidTest/resources/jtx/vjournal/two-events-without-exceptions.ics
new file mode 100644
index 0000000..ff7d460
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/two-events-without-exceptions.ics
@@ -0,0 +1,15 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VJOURNAL
+UID:event1
+DTSTAMP:20150826T132300Z
+SUMMARY:Event 1
+DTSTART:20131009T170000T
+END:VJOURNAL
+BEGIN:VJOURNAL
+UID:event2
+DTSTAMP:20150826T132300Z
+SUMMARY:Event 2
+DTSTART:20131009T180000T
+END:VJOURNAL
+END:VCALENDAR
\ No newline at end of file
diff --git a/src/androidTest/resources/jtx/vjournal/two-line-description-without-crlf.ics b/src/androidTest/resources/jtx/vjournal/two-line-description-without-crlf.ics
new file mode 100644
index 0000000..5b6a49a
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/two-line-description-without-crlf.ics
@@ -0,0 +1,14 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:Blabla
+BEGIN:VJOURNAL
+CLASS:PUBLIC
+CREATED;VALUE=DATE-TIME:20131008T205713
+LAST-MODIFIED;VALUE=DATE-TIME:20131008T205740
+SUMMARY:online Anmeldung
+DESCRIPTION:http://www.tgbornheim.de/index.php?sessionid=&page=&id=&sportce
+ ntergroup=&day=6
+UID:b99c41704b
+DTSTART;VALUE=DATE-TIME;TZID=Europe/Berlin:20131019T060000
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vjournal/utf8.ics b/src/androidTest/resources/jtx/vjournal/utf8.ics
new file mode 100644
index 0000000..8f39860
--- /dev/null
+++ b/src/androidTest/resources/jtx/vjournal/utf8.ics
@@ -0,0 +1,13 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VJOURNAL
+UID:utf8@ical4android.EventTest
+DTSTAMP:20150826T132300Z
+SUMMARY:© äö — üß
+DESCRIPTION:Test Description
+LOCATION:中华人民共和国
+COLOR:aliceblue
+ATTENDEE;CN=Cyrus Daboo;EMAIL=cyrus@example.com:mailto:opaque-token-1234@example.com
+X-UNKNOWN-PROP;param1=xxx:Unknown Value
+END:VJOURNAL
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/empty-priority.ics b/src/androidTest/resources/jtx/vtodo/empty-priority.ics
new file mode 100644
index 0000000..69ad1ae
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/empty-priority.ics
@@ -0,0 +1,14 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+X-WR-CALNAME:Wieseclan
+PRODID:-//The Horde Project//Horde iCalendar Library//EN
+BEGIN:VTODO
+UID:1d58e8e0-4fac-4632-8d43-ec79757490d2.1519164997000
+SUMMARY:Alex Geschenkeliste
+DESCRIPTION:[ ] Tip Toi Rund um die Uhr\n[ ] Ravensburger Wort für Wort\n[
+  ] Hula Hoop Reifen\n[ ] Pfeil und Bogen mit Zielscheibe\n[ ] Tip Toi
+  Spielwelt Autorennen
+PRIORITY:
+STATUS:NEEDS-ACTION
+END:VTODO
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/latin1.ics b/src/androidTest/resources/jtx/vtodo/latin1.ics
new file mode 100644
index 0000000..b3502de
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/latin1.ics
@@ -0,0 +1,9 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VTODO
+UID:latin1@ical4android.EventTest
+DTSTAMP:20150826T132300Z
+SUMMARY:����
+DTSTART:20131009T170000T
+END:VTODO
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/most-fields1.ics b/src/androidTest/resources/jtx/vtodo/most-fields1.ics
new file mode 100644
index 0000000..ff4dbb0
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/most-fields1.ics
@@ -0,0 +1,32 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//ABC Corporation//NONSGML My Product//EN
+BEGIN:VTODO
+SEQUENCE:1
+UID:most-fields1@example.com
+LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf":
+ Conference Room - F123\, Bldg. 002
+GEO:37.386013;-122.082932
+DESCRIPTION:Meeting to provide technical review for "Phoenix"
+  design.\nHappy Face Conference Room. Phoenix design team
+  MUST attend this meeting.\nRSVP to team leader.
+URL:http://example.com/pub/calendars/jsmith/mytime.ics
+ORGANIZER:http://example.com/principals/jsmith
+PRIORITY:1
+CLASS:CONFIDENTIAL
+STATUS:IN-PROCESS
+PERCENT-COMPLETE:25
+DTSTART;VALUE=DATE:20100101
+DUE;VALUE=DATE:20101001
+CATEGORIES:Test,Sample
+RRULE:FREQ=YEARLY;INTERVAL=2
+EXDATE;VALUE=DATE:20120101
+EXDATE;VALUE=DATE:20140101,20180101
+RDATE;VALUE=DATE:20100310,20100315
+RDATE;VALUE=DATE:20100810
+RELATED-TO;RELTYPE=SIBLING:most-fields2@example.com
+X-UNKNOWN-PROP;param1=xxx:Unknown Value
+CREATED:19960329T133000Z
+LAST-MODIFIED:19960817T133000Z
+END:VTODO
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/most-fields2.ics b/src/androidTest/resources/jtx/vtodo/most-fields2.ics
new file mode 100644
index 0000000..f6c7215
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/most-fields2.ics
@@ -0,0 +1,9 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//ABC Corporation//NONSGML My Product//EN
+BEGIN:VTODO
+UID:most-fields2@example.com
+DTSTART:20100101T101010Z
+DURATION:P4DT3H2M1S
+END:VTODO
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/rfc5545-sample1.ics b/src/androidTest/resources/jtx/vtodo/rfc5545-sample1.ics
new file mode 100644
index 0000000..18d53df
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/rfc5545-sample1.ics
@@ -0,0 +1,22 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//ABC Corporation//NONSGML My Product//EN
+BEGIN:VTODO
+DTSTAMP:19980130T134500Z
+SEQUENCE:2
+UID:uid4@example.com
+ORGANIZER:mailto:unclesam@example.com
+ATTENDEE;PARTSTAT=ACCEPTED:mailto:jqpublic@example.com
+DUE:19980415T000000
+STATUS:NEEDS-ACTION
+SUMMARY:Submit Income Taxes
+BEGIN:VALARM
+ACTION:AUDIO
+TRIGGER;VALUE=DATE-TIME:19980403T120000Z
+ATTACH;FMTTYPE=audio/basic:http://example.com/pub/audio-
+ files/ssbanner.aud
+REPEAT:4
+DURATION:PT1H
+END:VALARM
+END:VTODO
+END:VCALENDAR
diff --git a/src/androidTest/resources/jtx/vtodo/utf8.ics b/src/androidTest/resources/jtx/vtodo/utf8.ics
new file mode 100644
index 0000000..67aaa1e
--- /dev/null
+++ b/src/androidTest/resources/jtx/vtodo/utf8.ics
@@ -0,0 +1,10 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VTODO
+UID:utf8@ical4android.TaskTest
+DTSTAMP:20150826T132300Z
+SUMMARY:© äö — üß
+LOCATION:中华人民共和国
+DTSTART:20131009T170000T
+END:VTODO
+END:VCALENDAR
diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index 8f4f2c5..442d0ed 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -25,10 +25,15 @@
     <uses-permission android:name="org.tasks.permission.READ_TASKS" />
     <uses-permission android:name="org.tasks.permission.WRITE_TASKS" />
 
+    <!-- read/write tasks & journals (jtx Board) -->
+    <uses-permission android:name="at.techbee.jtx.permission.READ" />
+    <uses-permission android:name="at.techbee.jtx.permission.WRITE" />
+
     <application />
 
     <queries>
         <!-- task providers -->
+        <package android:name="at.techbee.jtx" />
         <package android:name="org.dmfs.tasks" />
         <package android:name="org.tasks" />
     </queries>
diff --git a/src/main/java/at/bitfire/ical4android/AndroidCalendar.kt b/src/main/java/at/bitfire/ical4android/AndroidCalendar.kt
index e0ac1bb..5736bde 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidCalendar.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidCalendar.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidCalendarFactory.kt b/src/main/java/at/bitfire/ical4android/AndroidCalendarFactory.kt
index 071ba9f..a0ba2b2 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidCalendarFactory.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidCalendarFactory.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidEvent.kt b/src/main/java/at/bitfire/ical4android/AndroidEvent.kt
index 3fed6b6..ec5981b 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidEvent.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidEvent.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidEventFactory.kt b/src/main/java/at/bitfire/ical4android/AndroidEventFactory.kt
index cd5f7e4..3136956 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidEventFactory.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidEventFactory.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidTask.kt b/src/main/java/at/bitfire/ical4android/AndroidTask.kt
index c776321..84af609 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidTask.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidTask.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidTaskFactory.kt b/src/main/java/at/bitfire/ical4android/AndroidTaskFactory.kt
index 0e35d7b..41d3f70 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidTaskFactory.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidTaskFactory.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidTaskList.kt b/src/main/java/at/bitfire/ical4android/AndroidTaskList.kt
index dd37586..4cd784b 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidTaskList.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidTaskList.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AndroidTaskListFactory.kt b/src/main/java/at/bitfire/ical4android/AndroidTaskListFactory.kt
index bc62a60..f7f33bd 100644
--- a/src/main/java/at/bitfire/ical4android/AndroidTaskListFactory.kt
+++ b/src/main/java/at/bitfire/ical4android/AndroidTaskListFactory.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/AttendeeMappings.kt b/src/main/java/at/bitfire/ical4android/AttendeeMappings.kt
index d6dea03..69d4baf 100644
--- a/src/main/java/at/bitfire/ical4android/AttendeeMappings.kt
+++ b/src/main/java/at/bitfire/ical4android/AttendeeMappings.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import android.content.ContentValues
diff --git a/src/main/java/at/bitfire/ical4android/BatchOperation.kt b/src/main/java/at/bitfire/ical4android/BatchOperation.kt
index 392b303..a7b881e 100644
--- a/src/main/java/at/bitfire/ical4android/BatchOperation.kt
+++ b/src/main/java/at/bitfire/ical4android/BatchOperation.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/CalendarStorageException.kt b/src/main/java/at/bitfire/ical4android/CalendarStorageException.kt
index 6ab3a67..85f463b 100644
--- a/src/main/java/at/bitfire/ical4android/CalendarStorageException.kt
+++ b/src/main/java/at/bitfire/ical4android/CalendarStorageException.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/Css3Color.kt b/src/main/java/at/bitfire/ical4android/Css3Color.kt
index b1b363f..57df5a2 100644
--- a/src/main/java/at/bitfire/ical4android/Css3Color.kt
+++ b/src/main/java/at/bitfire/ical4android/Css3Color.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/DateUtils.kt b/src/main/java/at/bitfire/ical4android/DateUtils.kt
index 52f8a98..c9ceffa 100644
--- a/src/main/java/at/bitfire/ical4android/DateUtils.kt
+++ b/src/main/java/at/bitfire/ical4android/DateUtils.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/Event.kt b/src/main/java/at/bitfire/ical4android/Event.kt
index c432511..d96ac73 100644
--- a/src/main/java/at/bitfire/ical4android/Event.kt
+++ b/src/main/java/at/bitfire/ical4android/Event.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/ICalPreprocessor.kt b/src/main/java/at/bitfire/ical4android/ICalPreprocessor.kt
index d43baae..ae7293c 100644
--- a/src/main/java/at/bitfire/ical4android/ICalPreprocessor.kt
+++ b/src/main/java/at/bitfire/ical4android/ICalPreprocessor.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.model.Calendar
diff --git a/src/main/java/at/bitfire/ical4android/ICalendar.kt b/src/main/java/at/bitfire/ical4android/ICalendar.kt
index aaffa1c..619f193 100644
--- a/src/main/java/at/bitfire/ical4android/ICalendar.kt
+++ b/src/main/java/at/bitfire/ical4android/ICalendar.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/Ical4Android.kt b/src/main/java/at/bitfire/ical4android/Ical4Android.kt
index f97752f..806e981 100644
--- a/src/main/java/at/bitfire/ical4android/Ical4Android.kt
+++ b/src/main/java/at/bitfire/ical4android/Ical4Android.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/InvalidCalendarException.kt b/src/main/java/at/bitfire/ical4android/InvalidCalendarException.kt
index 00f1467..6c0da58 100644
--- a/src/main/java/at/bitfire/ical4android/InvalidCalendarException.kt
+++ b/src/main/java/at/bitfire/ical4android/InvalidCalendarException.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/JtxCollection.kt b/src/main/java/at/bitfire/ical4android/JtxCollection.kt
new file mode 100644
index 0000000..a10ee42
--- /dev/null
+++ b/src/main/java/at/bitfire/ical4android/JtxCollection.kt
@@ -0,0 +1,265 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentUris
+import android.content.ContentValues
+import android.content.Context
+import android.net.Uri
+import at.bitfire.ical4android.MiscUtils.CursorHelper.toValues
+import at.techbee.jtx.JtxContract
+import at.techbee.jtx.JtxContract.asSyncAdapter
+import java.util.*
+
+open class JtxCollection<out T: JtxICalObject>(val account: Account,
+                                               val client: ContentProviderClient,
+                                               private val iCalObjectFactory: JtxICalObjectFactory<JtxICalObject>,
+                                               val id: Long) {
+
+    companion object {
+
+        fun create(account: Account, client: ContentProviderClient, values: ContentValues): Uri =
+            client.insert(JtxContract.JtxCollection.CONTENT_URI.asSyncAdapter(account), values)?: throw CalendarStorageException("Couldn't create JTX Collection")
+
+        fun<T: JtxCollection<JtxICalObject>> find(account: Account, client: ContentProviderClient, context: Context, factory: JtxCollectionFactory<T>, where: String?, whereArgs: Array<String>?): List<T> {
+            val collections = LinkedList<T>()
+            client.query(JtxContract.JtxCollection.CONTENT_URI.asSyncAdapter(account), null, where, whereArgs, null)?.use { cursor ->
+                while (cursor.moveToNext()) {
+                    val values = cursor.toValues()
+                    val collection = factory.newInstance(account, client, values.getAsLong(JtxContract.JtxCollection.ID))
+                    collection.populate(values, context)
+                    collections += collection
+                }
+            }
+            return collections
+        }
+    }
+
+
+    var url: String? = null
+    var displayname: String? = null
+    var syncstate: String? = null
+
+    var context: Context? = null
+
+
+    fun delete() {
+        client.delete(ContentUris.withAppendedId(JtxContract.JtxCollection.CONTENT_URI.asSyncAdapter(account), id), null, null)
+    }
+
+    fun update(values: ContentValues) {
+
+        client.update(ContentUris.withAppendedId(JtxContract.JtxCollection.CONTENT_URI.asSyncAdapter(account), id), values, null, null)
+    }
+
+    protected fun populate(values: ContentValues, context: Context) {
+        url = values.getAsString(JtxContract.JtxCollection.URL)
+        displayname = values.getAsString(JtxContract.JtxCollection.DISPLAYNAME)
+        syncstate = values.getAsString(JtxContract.JtxCollection.SYNC_VERSION)
+
+        this.context = context
+    }
+
+
+    /**
+     * Builds the JtxICalObject content uri with appended parameters for account and syncadapter
+     * @return the Uri for the JtxICalObject Sync in the content provider of jtx Board
+     */
+    fun jtxSyncURI(): Uri =
+        JtxContract.JtxICalObject.CONTENT_URI.buildUpon()
+            .appendQueryParameter(JtxContract.ACCOUNT_NAME, account.name)
+            .appendQueryParameter(JtxContract.ACCOUNT_TYPE, account.type)
+            .appendQueryParameter(JtxContract.CALLER_IS_SYNCADAPTER, "true")
+            .build()
+
+
+    /**
+     * @return a list of content values of the deleted jtxICalObjects
+     */
+    fun queryDeletedICalObjects(): List<ContentValues> {
+        val values = mutableListOf<ContentValues>()
+        client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), null, "${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ? AND ${JtxContract.JtxICalObject.DELETED} = ?", arrayOf(id.toString(), "1"), null).use { cursor ->
+            Ical4Android.log.fine("findDeleted: found ${cursor?.count} deleted records in ${account.name}")
+            while (cursor?.moveToNext() == true) {
+                values.add(cursor.toValues())
+            }
+        }
+        return values
+    }
+
+
+    /**
+     * @return a list of content values of the dirty jtxICalObjects
+     */
+    fun queryDirtyICalObjects(): List<ContentValues> {
+        val values = mutableListOf<ContentValues>()
+        client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), null, "${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ? AND ${JtxContract.JtxICalObject.DIRTY} = ?", arrayOf(id.toString(), "1"), null).use { cursor ->
+            Ical4Android.log.fine("findDirty: found ${cursor?.count} dirty records in ${account.name}")
+            while (cursor?.moveToNext() == true) {
+                values.add(cursor.toValues())
+            }
+        }
+        return values
+    }
+
+    /**
+     * @param [filename] of the entry that should be retrieved as content values
+     * @return Content Values of the found item with the given filename or null if the result was empty or more than 1
+     */
+    fun queryByFilename(filename: String): ContentValues? {
+        client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), null, "${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ? AND ${JtxContract.JtxICalObject.FILENAME} = ?", arrayOf(id.toString(), filename), null).use { cursor ->
+            Ical4Android.log.fine("queryByFilename: found ${cursor?.count} records in ${account.name}")
+            if (cursor?.count != 1)
+                return null
+            cursor.moveToFirst()
+            return cursor.toValues()
+        }
+    }
+
+    /**
+     * updates the flags of all entries in the collection with the given flag
+     * @param [flags] to be set
+     * @return the number of records that were updated
+     */
+    fun updateSetFlags(flags: Int): Int {
+        val values = ContentValues(1)
+        values.put(JtxContract.JtxICalObject.FLAGS, flags)
+        return client.update(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), values, "${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ? AND ${JtxContract.JtxICalObject.DIRTY} = ?", arrayOf(id.toString(), "0"))
+    }
+
+    /**
+     * deletes all entries with the given flags
+     * @param [flags] of the entries that should be deleted
+     * @return the number of deleted records
+     */
+    fun deleteByFlags(flags: Int) =
+        client.delete(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), "${JtxContract.JtxICalObject.DIRTY} = ? AND ${JtxContract.JtxICalObject.FLAGS} = ? ", arrayOf("0", flags.toString()))
+
+    /**
+     * Updates the eTag value of all entries within a collection to the given eTag
+     * @param [eTag] to be set (or null)
+     */
+    fun updateSetETag(eTag: String?) {
+        val values = ContentValues(1)
+        if(eTag == null)
+            values.putNull(JtxContract.JtxICalObject.ETAG)
+        else
+            values.put(JtxContract.JtxICalObject.ETAG, eTag)
+        client.update(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), values, "${JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID} = ?", arrayOf(id.toString()))
+    }
+
+
+    /**
+     * This function updates the Related-To relations in jtx Board.
+     * STEP 1: find entries to update (all entries with 0 in related-to). When inserting the relation, we only know the parent iCalObjectId and the related UID (but not the related iCalObjectId).
+     *         In this step we search for all Related-To relations where the LINKEDICALOBJEC_ID is not set, resolve it through the UID and set it.
+     * STEP 2/3: jtx Board saves the relations in both directions, the Parent has an entry for his Child, the Child has an entry for his Parent. Step 2 and Step 3 make sure, that the Child-Parent pair is
+     *         present in both directions.
+     */
+    fun updateRelatedTo() {
+        // STEP 1: first find entries to update (all entries with 0 in related-to)
+        client.query(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxRelatedto.TEXT), "${JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID} = ?", arrayOf("0"), null).use {
+            while(it?.moveToNext() == true) {
+                val uid2upddate = it.getString(0)
+
+                client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxICalObject.ID), "${JtxContract.JtxICalObject.UID} = ?", arrayOf(uid2upddate), null).use { idOfthisUidCursor ->
+                    if (idOfthisUidCursor?.moveToFirst() == true) {
+                        val idOfthisUid = idOfthisUidCursor.getLong(0)
+
+                        val updateContentValues = ContentValues()
+                        updateContentValues.put(
+                            JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID,
+                            idOfthisUid
+                        )
+
+                        client.update(
+                            JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(
+                                account
+                            ),
+                            updateContentValues,
+                            "${JtxContract.JtxRelatedto.TEXT} = ? AND ${JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID} = ?",
+                            arrayOf(uid2upddate, "0")
+                        )
+                    }
+                }
+            }
+        }
+
+
+        // STEP 2: query all related to that are linking their PARENTS and check if they also have the opposite relationship entered, if not, then add it
+        client.query(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxRelatedto.ICALOBJECT_ID, JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, JtxContract.JtxRelatedto.RELTYPE), "${JtxContract.JtxRelatedto.RELTYPE} = ?", arrayOf(JtxContract.JtxRelatedto.Reltype.PARENT.name), null).use {
+                cursorAllLinkedParents ->
+            while (cursorAllLinkedParents?.moveToNext() == true) {
+                val icalObjectId = cursorAllLinkedParents.getString(0)
+                val linkedIcalObjectId = cursorAllLinkedParents.getString(1)
+
+                client.query(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxRelatedto.ICALOBJECT_ID, JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, JtxContract.JtxRelatedto.RELTYPE), "${JtxContract.JtxRelatedto.ICALOBJECT_ID} = ? AND ${JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID} = ? AND ${JtxContract.JtxRelatedto.RELTYPE} = ?", arrayOf(linkedIcalObjectId.toString(), icalObjectId.toString(), JtxContract.JtxRelatedto.Reltype.CHILD.name), null).use {  cursor ->
+                    // if the query does not bring any result, then we insert the opposite relationship
+                    if (cursor?.moveToFirst() == false) {
+
+                        //get the UID of the linked entry
+                        client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxICalObject.UID), "${JtxContract.JtxICalObject.ID} = ?", arrayOf(linkedIcalObjectId.toString()), null).use {
+                                foundIcalObjectCursor ->
+
+                            if (foundIcalObjectCursor?.moveToFirst() == true) {
+                                val uid = foundIcalObjectCursor.getString(0)
+
+                                val cv = ContentValues().apply {
+                                    put(JtxContract.JtxRelatedto.ICALOBJECT_ID, linkedIcalObjectId)
+                                    put(JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, icalObjectId)
+                                    put(JtxContract.JtxRelatedto.RELTYPE, JtxContract.JtxRelatedto.Reltype.CHILD.name)
+                                    put(JtxContract.JtxRelatedto.TEXT, uid)
+                                }
+
+                                client.insert(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), cv)
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+
+        // STEP 3: query all related to that are linking their CHILD and check if they also have the opposite relationship entered, if not, then add it
+        client.query(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxRelatedto.ICALOBJECT_ID, JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, JtxContract.JtxRelatedto.RELTYPE), "${JtxContract.JtxRelatedto.RELTYPE} = ?", arrayOf(JtxContract.JtxRelatedto.Reltype.CHILD.name), null).use {
+                cursorAllLinkedParents ->
+            while (cursorAllLinkedParents?.moveToNext() == true) {
+
+                val icalObjectId = cursorAllLinkedParents.getLong(0)
+                val linkedIcalObjectId = cursorAllLinkedParents.getLong(1)
+
+                client.query(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxRelatedto.ICALOBJECT_ID, JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, JtxContract.JtxRelatedto.RELTYPE), "${JtxContract.JtxRelatedto.ICALOBJECT_ID} = ? AND ${JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID} = ? AND ${JtxContract.JtxRelatedto.RELTYPE} = ?", arrayOf(linkedIcalObjectId.toString(), icalObjectId.toString(), JtxContract.JtxRelatedto.Reltype.PARENT.name), null).use {
+                        cursor ->
+
+                    // if the query does not bring any result, then we insert the opposite relationship
+                    if (cursor?.moveToFirst() == false) {
+
+                        //get the UID of the linked entry
+                        client.query(JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(account), arrayOf(JtxContract.JtxICalObject.UID), "${JtxContract.JtxICalObject.ID} = ?", arrayOf(linkedIcalObjectId.toString()), null).use {
+                                foundIcalObjectCursor ->
+
+                            if(foundIcalObjectCursor?.moveToFirst() == true) {
+
+                                val uid = foundIcalObjectCursor.getString(0)
+
+                                val cv = ContentValues().apply {
+                                    put(JtxContract.JtxRelatedto.ICALOBJECT_ID, linkedIcalObjectId)
+                                    put(JtxContract.JtxRelatedto.LINKEDICALOBJECT_ID, icalObjectId)
+                                    put(JtxContract.JtxRelatedto.RELTYPE, JtxContract.JtxRelatedto.Reltype.PARENT.name)
+                                    put(JtxContract.JtxRelatedto.TEXT, uid)
+                                }
+
+                                client.insert(JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(account), cv)
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/src/main/java/at/bitfire/ical4android/JtxCollectionFactory.kt b/src/main/java/at/bitfire/ical4android/JtxCollectionFactory.kt
new file mode 100644
index 0000000..177b2d1
--- /dev/null
+++ b/src/main/java/at/bitfire/ical4android/JtxCollectionFactory.kt
@@ -0,0 +1,14 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+
+interface JtxCollectionFactory<out T: JtxCollection<JtxICalObject>> {
+
+    fun newInstance(account: Account, client: ContentProviderClient, id: Long): T
+
+}
\ No newline at end of file
diff --git a/src/main/java/at/bitfire/ical4android/JtxICalObject.kt b/src/main/java/at/bitfire/ical4android/JtxICalObject.kt
new file mode 100644
index 0000000..1b8a5f1
--- /dev/null
+++ b/src/main/java/at/bitfire/ical4android/JtxICalObject.kt
@@ -0,0 +1,1796 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.content.ContentUris
+import android.content.ContentValues
+import android.net.ParseException
+import android.net.Uri
+import android.os.ParcelFileDescriptor
+import android.util.Base64
+import android.util.Log
+import at.bitfire.ical4android.MiscUtils.CursorHelper.toValues
+import at.techbee.jtx.JtxContract
+import at.techbee.jtx.JtxContract.JtxICalObject.TZ_ALLDAY
+import at.techbee.jtx.JtxContract.asSyncAdapter
+import net.fortuna.ical4j.data.CalendarOutputter
+import net.fortuna.ical4j.data.ParserException
+import net.fortuna.ical4j.model.*
+import net.fortuna.ical4j.model.Calendar
+import net.fortuna.ical4j.model.Date
+import net.fortuna.ical4j.model.component.VAlarm
+import net.fortuna.ical4j.model.component.VJournal
+import net.fortuna.ical4j.model.component.VToDo
+import net.fortuna.ical4j.model.parameter.*
+import net.fortuna.ical4j.model.property.*
+import java.io.*
+import java.net.URI
+import java.net.URISyntaxException
+import java.time.format.DateTimeParseException
+import java.util.*
+import java.util.TimeZone
+import java.util.logging.Level
+
+open class JtxICalObject(
+    val collection: JtxCollection<JtxICalObject>
+) {
+
+    var id: Long = 0L
+    lateinit var component: String
+    var summary: String? = null
+    var description: String? = null
+    var dtstart: Long? = null
+    var dtstartTimezone: String? = null
+    var dtend: Long? = null
+    var dtendTimezone: String? = null
+
+    var classification: String? = null
+    var status: String? = null
+
+    var priority: Int? = null
+
+    var due: Long? = null      // VTODO only!
+    var dueTimezone: String? = null //VTODO only!
+    var completed: Long? = null // VTODO only!
+    var completedTimezone: String? = null //VTODO only!
+    var duration: String? = null //VTODO only!
+
+    var percent: Int? = null
+    var url: String? = null
+    var contact: String? = null
+    var geoLat: Double? = null
+    var geoLong: Double? = null
+    var location: String? = null
+    var locationAltrep: String? = null
+
+    var uid: String = "${System.currentTimeMillis()}-${UUID.randomUUID()}@at.techbee.jtx"
+
+    var created: Long = System.currentTimeMillis()
+    var dtstamp: Long = System.currentTimeMillis()
+    var lastModified: Long = System.currentTimeMillis()
+    var sequence: Long = 0
+
+    var color: Int? = null
+
+    var rrule: String? = null    //only for recurring events, see https://tools.ietf.org/html/rfc5545#section-3.8.5.3
+    var exdate: String? = null   //only for recurring events, see https://tools.ietf.org/html/rfc5545#section-3.8.5.1
+    var rdate: String? = null    //only for recurring events, see https://tools.ietf.org/html/rfc5545#section-3.8.5.2
+    var recurid: String? = null  //only for recurring events, see https://tools.ietf.org/html/rfc5545#section-3.8.5
+
+    var rstatus: String? = null
+
+    var collectionId: Long = collection.id
+
+    var dirty: Boolean = true
+    var deleted: Boolean = false
+
+    var fileName: String? = null
+    var eTag: String? = null
+    var scheduleTag: String? = null
+    var flags: Int = 0
+
+    var categories: MutableList<Category> = mutableListOf()
+    var attachments: MutableList<Attachment> = mutableListOf()
+    var attendees: MutableList<Attendee> = mutableListOf()
+    var comments: MutableList<Comment> = mutableListOf()
+    var organizer: Organizer? = null
+    var resources: MutableList<Resource> = mutableListOf()
+    var relatedTo: MutableList<RelatedTo> = mutableListOf()
+    var alarms: MutableList<Alarm> = mutableListOf()
+    var unknown: MutableList<Unknown> = mutableListOf()
+
+
+
+
+    data class Category(
+        var categoryId: Long = 0L,
+        var text: String? = null,
+        var language: String? = null,
+        var other: String? = null
+    )
+
+    data class Attachment(
+        var attachmentId: Long = 0L,
+        var uri: String? = null,
+        var binary: String? = null,
+        var fmttype: String? = null,
+        var other: String? = null,
+        var filename: String? = null,
+        var extension: String? = null,
+        var filesize: Long? = null
+    )
+
+    data class Comment(
+        var commentId: Long = 0L,
+        var text: String? = null,
+        var altrep: String? = null,
+        var language: String? = null,
+        var other: String? = null
+    )
+
+    data class RelatedTo(
+        var relatedtoId: Long = 0L,
+        var text: String? = null,
+        var reltype: String? = null,
+        var other: String? = null
+    )
+
+    data class Attendee(
+        var attendeeId: Long = 0L,
+        var caladdress: String? = null,
+        var cutype: String? = JtxContract.JtxAttendee.Cutype.INDIVIDUAL.name,
+        var member: String? = null,
+        var role: String? = JtxContract.JtxAttendee.Role.`REQ-PARTICIPANT`.name,
+        var partstat: String? = null,
+        var rsvp: Boolean? = null,
+        var delegatedto: String? = null,
+        var delegatedfrom: String? = null,
+        var sentby: String? = null,
+        var cn: String? = null,
+        var dir: String? = null,
+        var language: String? = null,
+        var other: String? = null
+    )
+
+    data class Resource(
+        var resourceId: Long = 0L,
+        var text: String? = null,
+        var altrep: String? = null,
+        var language: String? = null,
+        var other: String? = null
+    )
+
+    data class Organizer(
+        var organizerId: Long = 0L,
+        var caladdress: String? = null,
+        var cn: String? = null,
+        var dir: String? = null,
+        var sentby: String? = null,
+        var language: String? = null,
+        var other: String? = null
+    )
+
+    data class Alarm(
+        var alarmId: Long = 0L,
+        var action: String? = null,
+        var description: String? = null,
+        var summary: String? = null,
+        var attendee: String? = null,
+        var duration: String? = null,
+        var repeat: String? = null,
+        var attach: String? = null,
+        var other: String? = null,
+        var triggerTime: Long? = null,
+        var triggerTimezone: String? = null,
+        var triggerRelativeTo: String? = null,
+        var triggerRelativeDuration: String? = null
+    )
+
+    data class Unknown(
+        var unknownId: Long = 0L,
+        var value: String? = null
+    )
+
+
+    companion object {
+
+        const val X_PROP_COMPLETEDTIMEZONE = "X-COMPLETEDTIMEZONE"
+
+        const val MAX_ATTACHMENT_SYNC_SIZE = 102400 // = 100KB
+
+        /**
+         * Parses an iCalendar resource, applies [ICalPreprocessor] to increase compatibility
+         * and extracts the VTODOs and/or VJOURNALS.
+         *
+         * @param reader where the iCalendar is taken from
+         *
+         * @return array of filled [JtxICalObject] data objects (may have size 0)
+         *
+         * @throws ParserException when the iCalendar can't be parsed
+         * @throws IllegalArgumentException when the iCalendar resource contains an invalid value
+         * @throws IOException on I/O errors
+         */
+        @UsesThreadContextClassLoader
+        fun fromReader(
+            reader: Reader,
+            collection: JtxCollection<JtxICalObject>
+        ): List<JtxICalObject> {
+            val ical = ICalendar.fromReader(reader)
+
+            val iCalObjectList = mutableListOf<JtxICalObject>()
+
+            ical.components.forEach { component ->
+
+                val iCalObject = JtxICalObject(collection)
+
+                when(component) {
+                    is VToDo -> {
+                        iCalObject.component = JtxContract.JtxICalObject.Component.VTODO.name
+                        if (component.uid != null)
+                            iCalObject.uid = component.uid.value                         // generated UID is overwritten here (if present)
+                        extractProperties(iCalObject, component.properties)
+                        extractVAlarms(iCalObject, component.components)                 // accessing the components needs an explicit type
+                    }
+                    is VJournal -> {
+                        iCalObject.component = JtxContract.JtxICalObject.Component.VJOURNAL.name
+                        if (component.uid != null)
+                            iCalObject.uid = component.uid.value
+                        extractProperties(iCalObject, component.properties)
+                        extractVAlarms(iCalObject, component.components)                  // accessing the components needs an explicit type
+                    }
+                }
+                iCalObjectList.add(iCalObject)
+            }
+            return iCalObjectList
+        }
+
+        /**
+         * Extracts VAlarms from the given Component (VJOURNAL or VTODO). The VAlarm is supposed to be a component within the VJOURNAL or VTODO component.
+         * Other components than VAlarms should not occur.
+         * @param [iCalObject] where the VAlarms should be inserted
+         * @param [calComponents] from which the VAlarms should be extracted
+         */
+        private fun extractVAlarms(iCalObject: JtxICalObject, calComponents: ComponentList<*>) {
+
+            calComponents.forEach { component ->
+                if(component is VAlarm) {
+                    val jtxAlarm = Alarm().apply {
+                        component.action?.value?.let { vAlarmAction -> this.action = vAlarmAction }
+                        component.summary?.value?.let { vAlarmSummary -> this.summary = vAlarmSummary }
+                        component.description?.value?.let { vAlarmDesc -> this.description = vAlarmDesc }
+                        component.duration?.value?.let { vAlarmDur -> this.duration = vAlarmDur }
+                        component.attachment?.uri?.let { uri -> this.attach = uri.toString() }
+                        component.repeat?.value?.let { vAlarmRep -> this.repeat = vAlarmRep }
+
+                        // alarms can have a duration or an absolute dateTime, but not both!
+                        if(component.trigger.duration != null) {
+                            component.trigger?.duration?.let { duration -> this.triggerRelativeDuration = duration.toString() }
+                            component.trigger?.getParameter<Related>(Parameter.RELATED)?.let { related -> this.triggerRelativeTo = related.value }
+                        } else if(component.trigger.dateTime != null) {
+                            component.trigger?.dateTime?.let { dateTime -> this.triggerTime = dateTime.time  }
+                            component.trigger?.dateTime?.timeZone?.let { timezone -> this.triggerTimezone = timezone.id }
+                        }
+
+                        // remove properties to add the rest to other
+                        component.properties.remove(component.action)
+                        component.properties.remove(component.summary)
+                        component.properties.remove(component.description)
+                        component.properties.remove(component.duration)
+                        component.properties.remove(component.attachment)
+                        component.properties.remove(component.repeat)
+                        component.properties.remove(component.trigger)
+                        component.properties?.let { vAlarmProps -> this.other = JtxContract.getJsonStringFromXProperties(vAlarmProps) }
+                    }
+                    iCalObject.alarms.add(jtxAlarm)
+                }
+            }
+        }
+
+        /**
+         * Extracts properties from a given Property list and maps it to a JtxICalObject
+         * @param [iCalObject] where the properties should be mapped to
+         * @param [properties] from which the properties can be extracted
+         */
+        private fun extractProperties(iCalObject: JtxICalObject, properties: PropertyList<*>) {
+
+            // sequence must only be null for locally created, not-yet-synchronized events
+            iCalObject.sequence = 0
+
+            for (prop in properties) {
+                when (prop) {
+                    is Sequence -> iCalObject.sequence = prop.sequenceNo.toLong()
+                    is Created -> iCalObject.created = prop.dateTime.time
+                    is LastModified -> iCalObject.lastModified = prop.dateTime.time
+                    is Summary -> iCalObject.summary = prop.value
+                    is Location -> {
+                        iCalObject.location = prop.value
+                        if(!prop.parameters.isEmpty && prop.parameters.getParameter<AltRep>(Parameter.ALTREP) != null)
+                            iCalObject.locationAltrep = prop.parameters.getParameter<AltRep>(Parameter.ALTREP).value
+                    }
+                    is Geo -> {
+                        iCalObject.geoLat = prop.latitude.toDouble()
+                        iCalObject.geoLong = prop.longitude.toDouble()
+                    }
+                    is Description -> iCalObject.description = prop.value
+                    is Color -> iCalObject.color = Css3Color.fromString(prop.value)?.argb
+                    is Url -> iCalObject.url = prop.value
+                    is Priority -> iCalObject.priority = prop.level
+                    is Clazz -> iCalObject.classification = prop.value
+                    is Status -> iCalObject.status = prop.value
+                    is DtEnd -> Ical4Android.log.warning("The property DtEnd must not be used for VTODO and VJOURNAL, this value is rejected.")
+                    is Completed -> {
+                        if (iCalObject.component == JtxContract.JtxICalObject.Component.VTODO.name) {
+                            iCalObject.completed = prop.date.time
+                        } else
+                            Ical4Android.log.warning("The property Completed is only supported for VTODO, this value is rejected.")
+                    }
+
+                    is Due -> {
+                        if (iCalObject.component == JtxContract.JtxICalObject.Component.VTODO.name) {
+                            iCalObject.due = prop.date.time
+                            when {
+                                prop.date is DateTime && prop.timeZone != null -> iCalObject.dueTimezone = prop.timeZone.id
+                                prop.date is DateTime && prop.isUtc -> iCalObject.dueTimezone = TimeZone.getTimeZone("UTC").id
+                                prop.date is DateTime && !prop.isUtc && prop.timeZone == null -> iCalObject.dueTimezone = null                   // this comparison is kept on purpose as "prop.date is Date" did not work as expected.
+                                else -> iCalObject.dueTimezone = TZ_ALLDAY     // prop.date is Date (and not DateTime), therefore it must be Allday
+                            }
+                        } else
+                            Ical4Android.log.warning("The property Due is only supported for VTODO, this value is rejected.")
+                    }
+
+                    is Duration -> iCalObject.duration = prop.value
+
+                    is DtStart -> {
+                        iCalObject.dtstart = prop.date.time
+                        when {
+                            prop.date is DateTime && prop.timeZone != null -> iCalObject.dtstartTimezone = prop.timeZone.id
+                            prop.date is DateTime && prop.isUtc -> iCalObject.dtstartTimezone = TimeZone.getTimeZone("UTC").id
+                            prop.date is DateTime && !prop.isUtc && prop.timeZone == null -> iCalObject.dtstartTimezone = null                   // this comparison is kept on purpose as "prop.date is Date" did not work as expected.
+                            else -> iCalObject.dtstartTimezone = TZ_ALLDAY     // prop.date is Date (and not DateTime), therefore it must be Allday
+                        }
+                    }
+
+                    is PercentComplete -> {
+                        if (iCalObject.component == JtxContract.JtxICalObject.Component.VTODO.name)
+                            iCalObject.percent = prop.percentage
+                        else
+                            Ical4Android.log.warning("The property PercentComplete is only supported for VTODO, this value is rejected.")
+                    }
+
+                    is RRule -> iCalObject.rrule = prop.value
+                    is RDate -> {
+                        val rdateList = if(iCalObject.rdate.isNullOrEmpty())
+                            mutableListOf()
+                        else
+                            JtxContract.getLongListFromString(iCalObject.rdate!!)
+                        prop.dates.forEach {
+                            rdateList.add(it.time)
+                        }
+                        iCalObject.rdate = rdateList.toTypedArray().joinToString(separator = ",")
+                    }
+                    is ExDate -> {
+                        val exdateList = if(iCalObject.exdate.isNullOrEmpty())
+                            mutableListOf()
+                        else
+                            JtxContract.getLongListFromString(iCalObject.exdate!!)
+                        prop.dates.forEach {
+                            exdateList.add(it.time)
+                        }
+                        iCalObject.exdate = exdateList.toTypedArray().joinToString(separator = ",")
+                    }
+                    is RecurrenceId -> iCalObject.recurid = prop.value
+
+                    //is RequestStatus -> iCalObject.rstatus = prop.value
+
+                    is Categories ->
+                        for (category in prop.categories)
+                            iCalObject.categories.add(Category(text = category))
+
+                    is net.fortuna.ical4j.model.property.Comment -> {
+                        iCalObject.comments.add(
+                            Comment().apply {
+                                this.text = prop.value
+                                this.language = prop.parameters?.getParameter<Language>(Parameter.LANGUAGE)?.value
+                                this.altrep = prop.parameters?.getParameter<AltRep>(Parameter.ALTREP)?.value
+
+                                // remove the known parameter
+                                prop.parameters?.removeAll(Parameter.LANGUAGE)
+                                prop.parameters?.removeAll(Parameter.ALTREP)
+
+                                // save unknown parameters in the other field
+                                this.other = JtxContract.getJsonStringFromXParameters(prop.parameters)
+                            })
+
+                    }
+
+                    is Resources ->
+                        for (resource in prop.resources)
+                            iCalObject.resources.add(Resource(text = resource))
+
+                    is Attach -> {
+                        val attachment = Attachment()
+                        prop.uri?.let { attachment.uri = it.toString() }
+                        prop.binary?.let {
+                            attachment.binary = Base64.encodeToString(it, Base64.DEFAULT)
+                        }
+                        prop.parameters?.getParameter<FmtType>(Parameter.FMTTYPE)?.let {
+                            attachment.fmttype = it.value
+                            prop.parameters?.remove(it)
+                        }
+
+                        attachment.other = JtxContract.getJsonStringFromXParameters(prop.parameters)
+
+                        if (attachment.uri?.isNotEmpty() == true || attachment.binary?.isNotEmpty() == true)   // either uri or value must be present!
+                            iCalObject.attachments.add(attachment)
+                    }
+
+                    is net.fortuna.ical4j.model.property.RelatedTo -> {
+
+                        iCalObject.relatedTo.add(
+                            RelatedTo().apply {
+                                this.text = prop.value
+                                this.reltype = prop.getParameter<RelType>(RelType.RELTYPE)?.value ?: JtxContract.JtxRelatedto.Reltype.PARENT.name
+
+                                // remove the known parameter
+                                prop.parameters?.removeAll(RelType.RELTYPE)
+
+                                // save unknown parameters in the other field
+                                this.other = JtxContract.getJsonStringFromXParameters(prop.parameters)
+                            })
+                    }
+
+                    is net.fortuna.ical4j.model.property.Attendee -> {
+                        iCalObject.attendees.add(
+                            Attendee().apply {
+                                this.caladdress = prop.calAddress.toString()
+                                this.cn = prop.parameters?.getParameter<Cn>(Parameter.CN)?.value
+                                this.delegatedto = prop.parameters?.getParameter<DelegatedTo>(Parameter.DELEGATED_TO)?.value
+                                this.delegatedfrom = prop.parameters?.getParameter<DelegatedFrom>(Parameter.DELEGATED_FROM)?.value
+                                this.cutype = prop.parameters?.getParameter<CuType>(Parameter.CUTYPE)?.value
+                                this.dir = prop.parameters?.getParameter<Dir>(Parameter.DIR)?.value
+                                this.language = prop.parameters?.getParameter<Language>(Parameter.LANGUAGE)?.value
+                                this.member = prop.parameters?.getParameter<Member>(Parameter.MEMBER)?.value
+                                this.partstat = prop.parameters?.getParameter<PartStat>(Parameter.PARTSTAT)?.value
+                                this.role = prop.parameters?.getParameter<Role>(Parameter.ROLE)?.value
+                                this.rsvp = prop.parameters?.getParameter<Rsvp>(Parameter.RSVP)?.value?.toBoolean()
+                                this.sentby = prop.parameters?.getParameter<SentBy>(Parameter.SENT_BY)?.value
+
+                                // remove all known parameters so that only unknown parameters remain
+                                prop.parameters?.removeAll(Parameter.CN)
+                                prop.parameters?.removeAll(Parameter.DELEGATED_TO)
+                                prop.parameters?.removeAll(Parameter.DELEGATED_FROM)
+                                prop.parameters?.removeAll(Parameter.CUTYPE)
+                                prop.parameters?.removeAll(Parameter.DIR)
+                                prop.parameters?.removeAll(Parameter.LANGUAGE)
+                                prop.parameters?.removeAll(Parameter.MEMBER)
+                                prop.parameters?.removeAll(Parameter.PARTSTAT)
+                                prop.parameters?.removeAll(Parameter.ROLE)
+                                prop.parameters?.removeAll(Parameter.RSVP)
+                                prop.parameters?.removeAll(Parameter.SENT_BY)
+
+                                // save unknown parameters in the other field
+                                this.other = JtxContract.getJsonStringFromXParameters(prop.parameters)
+                            }
+                        )
+                    }
+                    is net.fortuna.ical4j.model.property.Organizer -> {
+                    iCalObject.organizer = Organizer().apply {
+                        this.caladdress = prop.calAddress.toString()
+                        this.cn = prop.parameters?.getParameter<Cn>(Parameter.CN)?.value
+                        this.dir = prop.parameters?.getParameter<Dir>(Parameter.DIR)?.value
+                        this.language = prop.parameters?.getParameter<Language>(Parameter.LANGUAGE)?.value
+                        this.sentby = prop.parameters?.getParameter<SentBy>(Parameter.SENT_BY)?.value
+
+                        // remove all known parameters so that only unknown parameters remain
+                        prop.parameters?.removeAll(Parameter.CN)
+                        prop.parameters?.removeAll(Parameter.DIR)
+                        prop.parameters?.removeAll(Parameter.LANGUAGE)
+                        prop.parameters?.removeAll(Parameter.SENT_BY)
+
+                        // save unknown parameters in the other field
+                        this.other = JtxContract.getJsonStringFromXParameters(prop.parameters)
+                    }
+                }
+
+                    is Uid -> iCalObject.uid = prop.value
+                    //is Uid,
+                    is ProdId, is DtStamp -> {
+                    }    /* don't save these as unknown properties */
+                    else -> {
+                        if(prop.name == X_PROP_COMPLETEDTIMEZONE)
+                            iCalObject.completedTimezone = prop.value
+                        else
+                            iCalObject.unknown.add(Unknown(value = UnknownProperty.toJsonString(prop)))               // save the whole property for unknown properties
+                    }
+                }
+            }
+
+
+            // There seem to be many invalid tasks out there because of some defect clients, do some validation.
+            val dtStartTZ = iCalObject.dtstartTimezone
+            val dueTZ = iCalObject.dueTimezone
+
+            if (dtStartTZ != null && dueTZ != null) {
+                if (dtStartTZ == TZ_ALLDAY && dueTZ != TZ_ALLDAY) {
+                    Ical4Android.log.warning("DTSTART is DATE but DUE is DATE-TIME, rewriting DTSTART to DATE-TIME")
+                    iCalObject.dtstartTimezone = dueTZ
+                } else if (dtStartTZ != TZ_ALLDAY && dueTZ == TZ_ALLDAY) {
+                    Ical4Android.log.warning("DTSTART is DATE-TIME but DUE is DATE, rewriting DUE to DATE-TIME")
+                    iCalObject.dueTimezone = dtStartTZ
+                }
+
+                if ( iCalObject.dtstart != null && iCalObject.due != null && iCalObject.due!! <= iCalObject.dtstart!!) {
+                    Ical4Android.log.warning("Found invalid DUE <= DTSTART; dropping DUE")     // Dtstart must not be dropped as it might be the basis for recurring tasks
+                    iCalObject.due = null
+                    iCalObject.dueTimezone = null
+                }
+            }
+
+            if (iCalObject.duration != null && iCalObject.dtstart == null) {
+                Ical4Android.log.warning("Found DURATION without DTSTART; ignoring")
+                iCalObject.duration = null
+            }
+        }
+    }
+
+    /**
+     * Takes the current JtxICalObject, transforms it to an iCalendar and writes it in an OutputStream
+     * @param [os] OutputStream where iCalendar should be written to
+     */
+    @UsesThreadContextClassLoader
+    fun write(os: OutputStream) {
+        Ical4Android.checkThreadContextClassLoader()
+
+        val ical = Calendar()
+        ical.properties += Version.VERSION_2_0
+        ical.properties += ICalendar.prodId
+
+        val calComponent = when (component) {
+            JtxContract.JtxICalObject.Component.VTODO.name -> VToDo(true /* generates DTSTAMP */)
+            JtxContract.JtxICalObject.Component.VJOURNAL.name -> VJournal(true /* generates DTSTAMP */)
+            else -> return
+        }
+        ical.components += calComponent
+        addProperties(calComponent.properties)
+
+        alarms.forEach { alarm ->
+
+            val vAlarm = VAlarm()
+            vAlarm.properties.apply {
+                alarm.action?.let {
+                    when (it) {
+                        JtxContract.JtxAlarm.AlarmAction.DISPLAY.name -> add(Action.DISPLAY)
+                        JtxContract.JtxAlarm.AlarmAction.AUDIO.name -> add(Action.AUDIO)
+                        JtxContract.JtxAlarm.AlarmAction.EMAIL.name -> add(Action.EMAIL)
+                        else -> return@let
+                    }
+                }
+                if(alarm.triggerRelativeDuration != null) {
+                    add(Trigger().apply {
+                        try {
+                            val dur = java.time.Duration.parse(alarm.triggerRelativeDuration)
+                            this.duration = dur
+
+                            // Add the RELATED parameter if present
+                            alarm.triggerRelativeTo?.let {
+                                if(it == JtxContract.JtxAlarm.AlarmRelativeTo.START.name)
+                                    this.parameters.add(Related.START)
+                                if(it == JtxContract.JtxAlarm.AlarmRelativeTo.END.name)
+                                    this.parameters.add(Related.END)
+                            }
+                        } catch (e: DateTimeParseException) {
+                            Ical4Android.log.log(Level.WARNING, "Could not parse Trigger duration as Duration.", e)
+                        }
+                    })
+
+                } else if (alarm.triggerTime != null) {
+                    add(Trigger().apply {
+                        try {
+                            when {
+                                alarm.triggerTimezone == TimeZone.getTimeZone("UTC").id -> this.dateTime = DateTime(alarm.triggerTime!!).apply {
+                                    this.isUtc = true
+                                }
+                                alarm.triggerTimezone.isNullOrEmpty() -> this.dateTime = DateTime(alarm.triggerTime!!).apply {
+                                    this.isUtc = true
+                                }
+                                else -> {
+                                    val timezone = TimeZoneRegistryFactory.getInstance().createRegistry()
+                                        .getTimeZone(alarm.triggerTimezone)
+                                    this.dateTime = DateTime(alarm.triggerTime!!).apply{
+                                        this.timeZone = timezone
+                                    }
+                                }
+                            }
+                        } catch (e: ParseException) {
+                            Ical4Android.log.log(Level.WARNING, "TriggerTime could not be parsed.", e)
+                        }})
+                }
+                alarm.summary?.let { add(Summary(it)) }
+                alarm.repeat?.let { add(Repeat().apply { value = it }) }
+                alarm.duration?.let { add(Duration().apply {
+                    try {
+                        val dur = java.time.Duration.parse(it)
+                        this.duration = dur
+                    } catch (e: DateTimeParseException) {
+                        Ical4Android.log.log(Level.WARNING, "Could not parse duration as Duration.", e)
+                    }
+                }) }
+                alarm.description?.let { add(Description(it)) }
+                alarm.attach?.let { add(Attach().apply { value = it }) }
+                alarm.other?.let { addAll(JtxContract.getXPropertyListFromJson(it)) }
+
+            }
+            calComponent.components.add(vAlarm)
+        }
+
+        ICalendar.softValidate(ical)
+        CalendarOutputter(false).output(ical, os)
+    }
+
+    /**
+     * This function maps the current JtxICalObject to a iCalendar property list
+     * @param [props] The PropertyList where the properties should be added
+     */
+    private fun addProperties(props: PropertyList<Property>) {
+
+        uid.let { props += Uid(it) }
+        sequence.let { props += Sequence(it.toInt()) }
+
+        created.let { props += Created(DateTime(it).apply {
+            this.isUtc = true
+        }) }
+        lastModified.let { props += LastModified(DateTime(it).apply {
+            this.isUtc = true
+        }) }
+
+        summary.let { props += Summary(it) }
+        description?.let { props += Description(it) }
+
+        location?.let { location ->
+            val loc = Location(location)
+            locationAltrep?.let { locationAltrep ->
+                loc.parameters.add(AltRep(locationAltrep))
+            }
+            props += loc
+        }
+        if (geoLat != null && geoLong != null) {
+            props += Geo(geoLat!!.toBigDecimal(), geoLong!!.toBigDecimal())
+        }
+        color?.let { props += Color(null, Css3Color.nearestMatch(it).name) }
+        url?.let {
+            try {
+                props += Url(URI(it))
+            } catch (e: URISyntaxException) {
+                Ical4Android.log.log(Level.WARNING, "Ignoring invalid task URL: $url", e)
+            }
+        }
+        //organizer?.let { props += it }
+
+
+        classification?.let { props += Clazz(it) }
+        status?.let { props += Status(it) }
+
+
+        val categoryTextList = TextList()
+        categories.forEach {
+            categoryTextList.add(it.text)
+        }
+        if (!categoryTextList.isEmpty)
+            props += Categories(categoryTextList)
+
+
+        val resourceTextList = TextList()
+        resources.forEach {
+            resourceTextList.add(it.text)
+        }
+        if (!resourceTextList.isEmpty)
+            props += Resources(resourceTextList)
+
+
+        comments.forEach { comment ->
+            val c = Comment(comment.text).apply {
+                comment.altrep?.let { this.parameters.add(AltRep(it)) }
+                comment.language?.let { this.parameters.add(Language(it)) }
+                comment.other?.let {
+                    val xparams = JtxContract.getXParametersFromJson(it)
+                    xparams.forEach { xparam ->
+                        this.parameters.add(xparam)
+                    }
+                }
+            }
+            props += c
+        }
+
+
+        attendees.forEach { attendee ->
+            val attendeeProp = net.fortuna.ical4j.model.property.Attendee().apply {
+                this.calAddress = URI(attendee.caladdress)
+
+                attendee.cn?.let {
+                    this.parameters.add(Cn(it))
+                }
+                attendee.cutype?.let {
+                    when {
+                        it.equals(CuType.INDIVIDUAL.value, ignoreCase = true) -> this.parameters.add(CuType.INDIVIDUAL)
+                        it.equals(CuType.GROUP.value, ignoreCase = true) -> this.parameters.add(CuType.GROUP)
+                        it.equals(CuType.ROOM.value, ignoreCase = true) -> this.parameters.add(CuType.ROOM)
+                        it.equals(CuType.RESOURCE.value, ignoreCase = true) -> this.parameters.add(CuType.RESOURCE)
+                        it.equals(CuType.UNKNOWN.value, ignoreCase = true) -> this.parameters.add(CuType.UNKNOWN)
+                        else -> this.parameters.add(CuType.UNKNOWN)
+                    }
+                }
+                attendee.delegatedfrom?.let {
+                    this.parameters.add(DelegatedFrom(it))
+                }
+                attendee.delegatedto?.let {
+                    this.parameters.add(DelegatedTo(it))
+                }
+                attendee.dir?.let {
+                    this.parameters.add(Dir(it))
+                }
+                attendee.language?.let {
+                    this.parameters.add(Language(it))
+                }
+                attendee.member?.let {
+                    this.parameters.add(Member(it))
+                }
+                attendee.partstat?.let {
+                    this.parameters.add(PartStat(it))
+                }
+                attendee.role?.let {
+                    this.parameters.add(Role(it))
+                }
+                attendee.rsvp?.let {
+                    this.parameters.add(Rsvp(it))
+                }
+                attendee.sentby?.let {
+                    this.parameters.add(SentBy(it))
+                }
+                attendee.other?.let {
+                    val params = JtxContract.getXParametersFromJson(it)
+                    params.forEach { xparam ->
+                        this.parameters.add(xparam)
+                    }
+                }
+            }
+            props += attendeeProp
+        }
+
+        organizer?.let { organizer ->
+            val organizerProp = net.fortuna.ical4j.model.property.Organizer().apply {
+                if(organizer.caladdress?.isNotEmpty() == true)
+                    this.calAddress = URI(organizer.caladdress)
+
+                organizer.cn?.let {
+                    this.parameters.add(Cn(it))
+                }
+                organizer.dir?.let {
+                    this.parameters.add(Dir(it))
+                }
+                organizer.language?.let {
+                    this.parameters.add(Language(it))
+                }
+                organizer.sentby?.let {
+                    this.parameters.add(SentBy(it))
+                }
+                organizer.other?.let {
+                    val params = JtxContract.getXParametersFromJson(it)
+                    params.forEach { xparam ->
+                        this.parameters.add(xparam)
+                    }
+                }
+            }
+            props += organizerProp
+        }
+
+        attachments.forEach { attachment ->
+
+            try {
+                if (attachment.uri?.startsWith("content://") == true) {
+
+                    val attachmentUri = ContentUris.withAppendedId(JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(collection.account), attachment.attachmentId)
+                    val attachmentFile = collection.client.openFile(attachmentUri, "r")
+                    val attachmentBytes = ParcelFileDescriptor.AutoCloseInputStream(attachmentFile).readBytes()
+                    if(attachmentBytes.size <= MAX_ATTACHMENT_SYNC_SIZE) {     // Sync only small attachments that are smaller than 100 KB, larger ones are ignored
+                        val att = Attach(attachmentBytes).apply {
+                            attachment.fmttype?.let { this.parameters.add(FmtType(it)) }
+                        }
+                        props += att
+                    }
+
+                } else {
+                    attachment.uri?.let { uri ->
+                        val att = Attach(URI(uri)).apply {
+                            attachment.fmttype?.let { this.parameters.add(FmtType(it)) }
+                        }
+                        props += att
+                    }
+                }
+            } catch (e: FileNotFoundException) {
+                Ical4Android.log.log(Level.WARNING, "File not found at the given Uri: ${attachment.uri}", e)
+            } catch (e: NullPointerException) {
+                Ical4Android.log.log(Level.WARNING, "Provided Uri was empty: ${attachment.uri}", e)
+            } catch (e: IllegalArgumentException) {
+                Ical4Android.log.log(Level.WARNING, "Uri could not be parsed: ${attachment.uri}", e)
+            }
+        }
+
+        unknown.forEach {
+            it.value?.let {  jsonString ->
+                props.add(UnknownProperty.fromJsonString(jsonString))
+            }
+        }
+
+        relatedTo.forEach {
+            val param: Parameter =
+                when (it.reltype) {
+                    RelType.CHILD.value -> RelType.CHILD
+                    RelType.SIBLING.value -> RelType.SIBLING
+                    RelType.PARENT.value -> RelType.PARENT
+                    else -> return@forEach
+                }
+            val parameterList = ParameterList()
+            parameterList.add(param)
+            props += RelatedTo(parameterList, it.text)
+        }
+
+        dtstart?.let {
+            when {
+                dtstartTimezone == TZ_ALLDAY -> props += DtStart(Date(it))
+                dtstartTimezone == TimeZone.getTimeZone("UTC").id -> props += DtStart(DateTime(it).apply {
+                    this.isUtc = true
+                })
+                dtstartTimezone.isNullOrEmpty() -> props += DtStart(DateTime(it).apply {
+                    this.isUtc = false
+                })
+                else -> {
+                    val timezone = TimeZoneRegistryFactory.getInstance().createRegistry()
+                        .getTimeZone(dtstartTimezone)
+                    val withTimezone = DtStart(DateTime(it))
+                    withTimezone.timeZone = timezone
+                    props += withTimezone
+                }
+            }
+        }
+
+        rrule?.let { rrule ->
+            props += RRule(rrule)
+        }
+        recurid?.let { recurid ->
+            props += RecurrenceId(recurid)
+        }
+
+        rdate?.let { rdateString ->
+
+            when {
+                dtstartTimezone == TZ_ALLDAY -> {
+                    val dateListDate = DateList(Value.DATE)
+                    JtxContract.getLongListFromString(rdateString).forEach {
+                        dateListDate.add(Date(it))
+                    }
+                    props += RDate(dateListDate)
+
+                }
+                dtstartTimezone == TimeZone.getTimeZone("UTC").id -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    JtxContract.getLongListFromString(rdateString).forEach {
+                        dateListDateTime.add(DateTime(it).apply {
+                            this.isUtc = true
+                        })
+                    }
+                    props += RDate(dateListDateTime)
+                }
+                dtstartTimezone.isNullOrEmpty() -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    JtxContract.getLongListFromString(rdateString).forEach {
+                        dateListDateTime.add(DateTime(it).apply {
+                            this.isUtc = false
+                        })
+                    }
+                    props += RDate(dateListDateTime)
+                }
+                else -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    val timezone = TimeZoneRegistryFactory.getInstance().createRegistry().getTimeZone(dtstartTimezone)
+                    JtxContract.getLongListFromString(rdateString).forEach {
+                        val withTimezone = DateTime(it)
+                        withTimezone.timeZone = timezone
+                        dateListDateTime.add(DateTime(withTimezone))
+                    }
+                    props += RDate(dateListDateTime)
+                }
+            }
+        }
+
+        exdate?.let { exdateString ->
+
+            when {
+                dtstartTimezone == TZ_ALLDAY -> {
+                    val dateListDate = DateList(Value.DATE)
+                    JtxContract.getLongListFromString(exdateString).forEach {
+                        dateListDate.add(Date(it))
+                    }
+                    props += ExDate(dateListDate)
+
+                }
+                dtstartTimezone == TimeZone.getTimeZone("UTC").id -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    JtxContract.getLongListFromString(exdateString).forEach {
+                        dateListDateTime.add(DateTime(it).apply {
+                            this.isUtc = true
+                        })
+                    }
+                    props += ExDate(dateListDateTime)
+                }
+                dtstartTimezone.isNullOrEmpty() -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    JtxContract.getLongListFromString(exdateString).forEach {
+                        dateListDateTime.add(DateTime(it).apply {
+                            this.isUtc = false
+                        })
+                    }
+                    props += ExDate(dateListDateTime)
+                }
+                else -> {
+                    val dateListDateTime = DateList(Value.DATE_TIME)
+                    val timezone = TimeZoneRegistryFactory.getInstance().createRegistry().getTimeZone(dtstartTimezone)
+                    JtxContract.getLongListFromString(exdateString).forEach {
+                        val withTimezone = DateTime(it)
+                        withTimezone.timeZone = timezone
+                        dateListDateTime.add(DateTime(withTimezone))
+                    }
+                    props += ExDate(dateListDateTime)
+                }
+            }
+        }
+
+        duration?.let {
+            val dur = Duration()
+            dur.value = it
+            props += dur
+        }
+
+
+        /*
+// remember used time zones
+val usedTimeZones = HashSet<TimeZone>()
+duration?.let(props::add)
+*/
+
+
+        if(component == JtxContract.JtxICalObject.Component.VTODO.name) {
+            completed?.let {
+                //Completed is defines as always DateTime! And is always UTC!?
+
+                props += Completed(DateTime(it))
+            }
+            completedTimezone?.let {
+                props += XProperty(X_PROP_COMPLETEDTIMEZONE, it)
+            }
+            percent?.let {
+                props += PercentComplete(it)
+            }
+
+
+            if (priority != null && priority != Priority.UNDEFINED.level)
+                priority?.let {
+                    props += Priority(it)
+                }
+            else {
+                props += Priority(Priority.UNDEFINED.level)
+            }
+
+            due?.let {
+                when {
+                    dueTimezone == TZ_ALLDAY -> props += Due(Date(it))
+                    dueTimezone == TimeZone.getTimeZone("UTC").id -> props += Due(DateTime(it).apply {
+                    this.isUtc = true
+                    })
+                    dueTimezone.isNullOrEmpty() -> props += Due(DateTime(it).apply {
+                        this.isUtc = false
+                    })
+                    else -> {
+                        val timezone = TimeZoneRegistryFactory.getInstance().createRegistry()
+                            .getTimeZone(dueTimezone)
+                        val withTimezone = Due(DateTime(it))
+                        withTimezone.timeZone = timezone
+                        props += withTimezone
+                    }
+                }
+            }
+        }
+
+        /*
+
+    // determine earliest referenced date
+    val earliest = arrayOf(
+        dtStart?.date,
+        due?.date,
+        completedAt?.date
+    ).filterNotNull().min()
+    // add VTIMEZONE components
+    for (tz in usedTimeZones)
+        ical.components += ICalendar.minifyVTimeZone(tz.vTimeZone, earliest)
+*/
+    }
+
+
+    fun prepareForUpload(): String {
+        return "${this.uid}.ics"
+    }
+
+    /**
+     * Updates the fileName, eTag and scheduleTag of the current JtxICalObject
+     */
+    fun clearDirty(fileName: String?, eTag: String?, scheduleTag: String?) {
+
+        var updateUri = JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(collection.account)
+        updateUri = Uri.withAppendedPath(updateUri, this.id.toString())
+
+        val values = ContentValues()
+        fileName?.let { values.put(JtxContract.JtxICalObject.FILENAME, fileName) }
+        eTag?.let { values.put(JtxContract.JtxICalObject.ETAG, eTag) }
+        scheduleTag?.let { values.put(JtxContract.JtxICalObject.SCHEDULETAG, scheduleTag) }
+        values.put(JtxContract.JtxICalObject.DIRTY, false)
+
+        collection.client.update(updateUri, values, null, null)
+    }
+
+    /**
+     * Updates the flags of the current JtxICalObject
+     * @param [flags] to be set as [Int]
+     */
+    fun updateFlags(flags: Int) {
+
+        var updateUri = JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(collection.account)
+        updateUri = Uri.withAppendedPath(updateUri, this.id.toString())
+
+        val values = ContentValues()
+        values.put(JtxContract.JtxICalObject.FLAGS, flags)
+
+        collection.client.update(updateUri, values, null, null)
+    }
+
+    /**
+     * adds the current JtxICalObject in the jtx DB through the provider
+     * @return the Content [Uri] of the inserted object
+     */
+    fun add(): Uri {
+        val values = this.toContentValues()
+
+        val newUri = collection.client.insert(
+            JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(collection.account),
+            values
+        ) ?: return Uri.EMPTY
+        this.id = newUri.lastPathSegment?.toLong() ?: return Uri.EMPTY
+
+        insertOrUpdateListProperties(false)
+
+        return newUri
+    }
+
+    /**
+     * Updates the current JtxICalObject with the given data
+     * @param [data] The JtxICalObject with the information that should be applied to this object and updated in the provider
+     * @return [Uri] of the updated entry
+     */
+    fun update(data: JtxICalObject): Uri {
+
+        this.applyNewData(data)
+        val values = this.toContentValues()
+
+        var updateUri = JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(collection.account)
+        updateUri = Uri.withAppendedPath(updateUri, this.id.toString())
+        collection.client.update(
+            updateUri,
+            values,
+            "${JtxContract.JtxICalObject.ID} = ?",
+            arrayOf(this.id.toString())
+        )
+
+        insertOrUpdateListProperties(true)
+
+        return updateUri
+    }
+
+
+    /**
+     * This function takes care of all list properties and inserts them in the DB through the provider
+     * @param isUpdate if true then the list properties are deleted through the provider before they are inserted
+     */
+    private fun insertOrUpdateListProperties(isUpdate: Boolean) {
+
+        // delete the categories, attendees, ... and insert them again after. Only relevant for Update, for an insert there will be no entries
+        if (isUpdate) {
+            collection.client.delete(
+                JtxContract.JtxCategory.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxCategory.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxComment.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxComment.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxResource.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxResource.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxRelatedto.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxAttendee.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxAttendee.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxOrganizer.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxOrganizer.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxAttachment.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxAlarm.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+
+            collection.client.delete(
+                JtxContract.JtxUnknown.CONTENT_URI.asSyncAdapter(collection.account),
+                "${JtxContract.JtxUnknown.ICALOBJECT_ID} = ?",
+                arrayOf(this.id.toString())
+            )
+        }
+
+        this.categories.forEach { category ->
+            val categoryContentValues = ContentValues().apply {
+                put(JtxContract.JtxCategory.ICALOBJECT_ID, id)
+                put(JtxContract.JtxCategory.TEXT, category.text)
+                put(JtxContract.JtxCategory.ID, category.categoryId)
+                put(JtxContract.JtxCategory.LANGUAGE, category.language)
+                put(JtxContract.JtxCategory.OTHER, category.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxCategory.CONTENT_URI.asSyncAdapter(collection.account),
+                categoryContentValues
+            )
+        }
+
+        this.comments.forEach { comment ->
+            val commentContentValues = ContentValues().apply {
+                put(JtxContract.JtxComment.ICALOBJECT_ID, id)
+                put(JtxContract.JtxComment.ID, comment.commentId)
+                put(JtxContract.JtxComment.TEXT, comment.text)
+                put(JtxContract.JtxComment.LANGUAGE, comment.language)
+                put(JtxContract.JtxComment.OTHER, comment.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxComment.CONTENT_URI.asSyncAdapter(collection.account),
+                commentContentValues
+            )
+        }
+
+
+        this.resources.forEach { resource ->
+            val resourceContentValues = ContentValues().apply {
+                put(JtxContract.JtxResource.ICALOBJECT_ID, id)
+                put(JtxContract.JtxResource.ID, resource.resourceId)
+                put(JtxContract.JtxResource.TEXT, resource.text)
+                put(JtxContract.JtxResource.LANGUAGE, resource.language)
+                put(JtxContract.JtxResource.OTHER, resource.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxResource.CONTENT_URI.asSyncAdapter(collection.account),
+                resourceContentValues
+            )
+        }
+
+
+        this.relatedTo.forEach { related ->
+            val relatedToContentValues = ContentValues().apply {
+                put(JtxContract.JtxRelatedto.ICALOBJECT_ID, id)
+                put(JtxContract.JtxRelatedto.TEXT, related.text)
+                put(JtxContract.JtxRelatedto.RELTYPE, related.reltype)
+                put(JtxContract.JtxRelatedto.OTHER, related.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(collection.account),
+                relatedToContentValues
+            )
+        }
+
+        this.attendees.forEach { attendee ->
+            val attendeeContentValues = ContentValues().apply {
+                put(JtxContract.JtxAttendee.ICALOBJECT_ID, id)
+                put(JtxContract.JtxAttendee.CALADDRESS, attendee.caladdress)
+                put(JtxContract.JtxAttendee.CN, attendee.cn)
+                put(JtxContract.JtxAttendee.CUTYPE, attendee.cutype)
+                put(JtxContract.JtxAttendee.DELEGATEDFROM, attendee.delegatedfrom)
+                put(JtxContract.JtxAttendee.DELEGATEDTO, attendee.delegatedto)
+                put(JtxContract.JtxAttendee.DIR, attendee.dir)
+                put(JtxContract.JtxAttendee.LANGUAGE, attendee.language)
+                put(JtxContract.JtxAttendee.MEMBER, attendee.member)
+                put(JtxContract.JtxAttendee.PARTSTAT, attendee.partstat)
+                put(JtxContract.JtxAttendee.ROLE, attendee.role)
+                put(JtxContract.JtxAttendee.RSVP, attendee.rsvp)
+                put(JtxContract.JtxAttendee.SENTBY, attendee.sentby)
+                put(JtxContract.JtxAttendee.OTHER, attendee.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxAttendee.CONTENT_URI.asSyncAdapter(
+                    collection.account
+                ), attendeeContentValues
+            )
+        }
+
+        this.organizer.let { organizer ->
+            val organizerContentValues = ContentValues().apply {
+                put(JtxContract.JtxOrganizer.ICALOBJECT_ID, id)
+                put(JtxContract.JtxOrganizer.CALADDRESS, organizer?.caladdress)
+
+                put(JtxContract.JtxOrganizer.CN, organizer?.cn)
+                put(JtxContract.JtxOrganizer.DIR, organizer?.dir)
+                put(JtxContract.JtxOrganizer.LANGUAGE, organizer?.language)
+                put(JtxContract.JtxOrganizer.SENTBY, organizer?.sentby)
+                put(JtxContract.JtxOrganizer.OTHER, organizer?.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxOrganizer.CONTENT_URI.asSyncAdapter(
+                    collection.account
+                ), organizerContentValues
+            )
+        }
+
+        this.attachments.forEach { attachment ->
+            val attachmentContentValues = ContentValues().apply {
+                put(JtxContract.JtxAttachment.ICALOBJECT_ID, id)
+                put(JtxContract.JtxAttachment.URI, attachment.uri)
+                put(JtxContract.JtxAttachment.FMTTYPE, attachment.fmttype)
+                put(JtxContract.JtxAttachment.OTHER, attachment.other)
+            }
+            val newAttachment = collection.client.insert(
+                JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(
+                    collection.account
+                ), attachmentContentValues
+            )
+            if(attachment.uri.isNullOrEmpty() && newAttachment != null) {
+                val attachmentPFD = collection.client.openFile(newAttachment, "w")
+                ParcelFileDescriptor.AutoCloseOutputStream(attachmentPFD).write(Base64.decode(attachment.binary, Base64.DEFAULT))
+            }
+        }
+
+        this.alarms.forEach { alarm ->
+            val alarmContentValues = ContentValues().apply {
+                put(JtxContract.JtxAlarm.ICALOBJECT_ID, id)
+                put(JtxContract.JtxAlarm.ACTION, alarm.action)
+                put(JtxContract.JtxAlarm.ATTACH, alarm.attach)
+                //put(JtxContract.JtxAlarm.ATTENDEE, alarm.attendee)
+                put(JtxContract.JtxAlarm.DESCRIPTION, alarm.description)
+                put(JtxContract.JtxAlarm.DURATION, alarm.duration)
+                put(JtxContract.JtxAlarm.REPEAT, alarm.repeat)
+                put(JtxContract.JtxAlarm.SUMMARY, alarm.summary)
+                put(JtxContract.JtxAlarm.TRIGGER_RELATIVE_TO, alarm.triggerRelativeTo)
+                put(JtxContract.JtxAlarm.TRIGGER_RELATIVE_DURATION, alarm.triggerRelativeDuration)
+                put(JtxContract.JtxAlarm.TRIGGER_TIME, alarm.triggerTime)
+                put(JtxContract.JtxAlarm.TRIGGER_TIMEZONE, alarm.triggerTimezone)
+                put(JtxContract.JtxAlarm.OTHER, alarm.other)
+            }
+            collection.client.insert(
+                JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(collection.account),
+                alarmContentValues
+            )
+        }
+
+        this.unknown.forEach { unknown ->
+            val unknownContentValues = ContentValues().apply {
+                put(JtxContract.JtxUnknown.ICALOBJECT_ID, id)
+                put(JtxContract.JtxUnknown.UNKNOWN_VALUE, unknown.value)
+            }
+            collection.client.insert(
+                JtxContract.JtxUnknown.CONTENT_URI.asSyncAdapter(collection.account),
+                unknownContentValues
+            )
+        }
+    }
+
+    /**
+     * Deletes the current JtxICalObject
+     * @return The number of deleted records (should always be 1)
+     */
+    fun delete(): Int {
+        val uri = Uri.withAppendedPath(
+            JtxContract.JtxICalObject.CONTENT_URI.asSyncAdapter(collection.account),
+            id.toString()
+        )
+        return collection.client.delete(uri, null, null)
+    }
+
+
+    /**
+     * This function is used for empty JtxICalObjects that need new data applied, usually a LocalJtxICalObject.
+     * @param [newData], the (local) JtxICalObject that should be mapped onto the given JtxICalObject
+     */
+    fun applyNewData(newData: JtxICalObject) {
+
+        this.component = newData.component
+        this.sequence = newData.sequence
+        this.created = newData.created
+        this.lastModified = newData.lastModified
+        this.summary = newData.summary
+        this.description = newData.description
+        this.uid = newData.uid
+
+        this.location = newData.location
+        this.locationAltrep = newData.locationAltrep
+        this.geoLat = newData.geoLat
+        this.geoLong = newData.geoLong
+        this.percent = newData.percent
+        this.classification = newData.classification
+        this.status = newData.status
+        this.priority = newData.priority
+
+        this.dtstart = newData.dtstart
+        this.dtstartTimezone = newData.dtstartTimezone
+        this.dtend = newData.dtend
+        this.dtendTimezone = newData.dtendTimezone
+        this.completed = newData.completed
+        this.completedTimezone = newData.completedTimezone
+        this.due = newData.due
+        this.dueTimezone = newData.dueTimezone
+        this.duration = newData.duration
+
+        this.rrule = newData.rrule
+        this.rdate = newData.rdate
+        this.exdate = newData.exdate
+        this.recurid = newData.recurid
+
+
+        this.categories = newData.categories
+        this.comments = newData.comments
+        this.resources = newData.resources
+        this.relatedTo = newData.relatedTo
+        this.attendees = newData.attendees
+        this.organizer = newData.organizer
+        this.attachments = newData.attachments
+        this.alarms = newData.alarms
+        this.unknown = newData.unknown
+    }
+
+    /**
+     * Takes Content Values, applies them on the current JtxICalObject and retrieves all further list properties from the content provier and adds them.
+     * @param [values] The Content Values with the information about the JtxICalObject
+     */
+    fun populateFromContentValues(values: ContentValues) {
+
+            values.getAsLong(JtxContract.JtxICalObject.ID)?.let { id -> this.id = id }
+
+            values.getAsString(JtxContract.JtxICalObject.COMPONENT)?.let { component -> this.component = component }
+            values.getAsString(JtxContract.JtxICalObject.SUMMARY)?.let { summary -> this.summary = summary }
+            values.getAsString(JtxContract.JtxICalObject.DESCRIPTION)?.let { description -> this.description = description }
+            values.getAsLong(JtxContract.JtxICalObject.DTSTART)?.let { dtstart -> this.dtstart = dtstart }
+            values.getAsString(JtxContract.JtxICalObject.DTSTART_TIMEZONE)?.let { dtstartTimezone -> this.dtstartTimezone = dtstartTimezone }
+            values.getAsLong(JtxContract.JtxICalObject.DTEND)?.let { dtend -> this.dtend = dtend }
+            values.getAsString(JtxContract.JtxICalObject.DTEND_TIMEZONE)?.let { dtendTimezone -> this.dtendTimezone = dtendTimezone }
+            values.getAsString(JtxContract.JtxICalObject.STATUS)?.let { status -> this.status = status }
+            values.getAsString(JtxContract.JtxICalObject.CLASSIFICATION)?.let { classification -> this.classification = classification }
+            values.getAsString(JtxContract.JtxICalObject.URL)?.let { url -> this.url = url }
+            values.getAsDouble(JtxContract.JtxICalObject.GEO_LAT)?.let { geoLat -> this.geoLat = geoLat }
+            values.getAsDouble(JtxContract.JtxICalObject.GEO_LONG)?.let { geoLong -> this.geoLong = geoLong }
+            values.getAsString(JtxContract.JtxICalObject.LOCATION)?.let { location -> this.location = location }
+            values.getAsString(JtxContract.JtxICalObject.LOCATION_ALTREP)?.let { locationAltrep -> this.locationAltrep = locationAltrep }
+            values.getAsInteger(JtxContract.JtxICalObject.PERCENT)?.let { percent -> this.percent = percent }
+            values.getAsInteger(JtxContract.JtxICalObject.PRIORITY)?.let { priority -> this.priority = priority }
+            values.getAsLong(JtxContract.JtxICalObject.DUE)?.let { due -> this.due = due }
+            values.getAsString(JtxContract.JtxICalObject.DUE_TIMEZONE)?.let { dueTimezone -> this.dueTimezone = dueTimezone }
+            values.getAsLong(JtxContract.JtxICalObject.COMPLETED)?.let { completed -> this.completed = completed }
+            values.getAsString(JtxContract.JtxICalObject.COMPLETED_TIMEZONE)?.let { completedTimezone -> this.completedTimezone = completedTimezone }
+            values.getAsString(JtxContract.JtxICalObject.DURATION)?.let { duration -> this.duration = duration }
+            values.getAsString(JtxContract.JtxICalObject.UID)?.let { uid -> this.uid = uid }
+            values.getAsLong(JtxContract.JtxICalObject.CREATED)?.let { created -> this.created = created }
+            values.getAsLong(JtxContract.JtxICalObject.DTSTAMP)?.let { dtstamp -> this.dtstamp = dtstamp }
+            values.getAsLong(JtxContract.JtxICalObject.LAST_MODIFIED)?.let { lastModified -> this.lastModified = lastModified }
+            values.getAsLong(JtxContract.JtxICalObject.SEQUENCE)?.let { sequence -> this.sequence = sequence }
+            values.getAsInteger(JtxContract.JtxICalObject.COLOR)?.let { color -> this.color = color }
+
+            values.getAsString(JtxContract.JtxICalObject.RRULE)?.let { rrule -> this.rrule = rrule }
+            values.getAsString(JtxContract.JtxICalObject.EXDATE)?.let { exdate -> this.exdate = exdate }
+            values.getAsString(JtxContract.JtxICalObject.RDATE)?.let { rdate -> this.rdate = rdate }
+            values.getAsString(JtxContract.JtxICalObject.RECURID)?.let { recurid -> this.recurid = recurid }
+
+            this.collectionId = collection.id
+            values.getAsBoolean(JtxContract.JtxICalObject.DIRTY)?.let { dirty -> this.dirty = dirty }
+            values.getAsBoolean(JtxContract.JtxICalObject.DELETED)?.let { deleted -> this.deleted = deleted }
+
+            values.getAsString(JtxContract.JtxICalObject.FILENAME)?.let { fileName -> this.fileName = fileName }
+            values.getAsString(JtxContract.JtxICalObject.ETAG)?.let { eTag -> this.eTag = eTag }
+            values.getAsString(JtxContract.JtxICalObject.SCHEDULETAG)?.let { scheduleTag -> this.scheduleTag = scheduleTag }
+            values.getAsInteger(JtxContract.JtxICalObject.FLAGS)?.let { flags -> this.flags = flags }
+
+
+        // Take care of categories
+        val categoriesContentValues = getCategoryContentValues()
+        categoriesContentValues.forEach { catValues ->
+            val category = Category().apply {
+                catValues.getAsLong(JtxContract.JtxCategory.ID)?.let { id -> this.categoryId = id }
+                catValues.getAsString(JtxContract.JtxCategory.TEXT)?.let { text -> this.text = text }
+                catValues.getAsString(JtxContract.JtxCategory.LANGUAGE)?.let { language -> this.language = language }
+                catValues.getAsString(JtxContract.JtxCategory.OTHER)?.let { other -> this.other = other }
+            }
+            categories.add(category)
+        }
+
+        // Take care of comments
+        val commentsContentValues = getCommentContentValues()
+        commentsContentValues.forEach { commentValues ->
+            val comment = Comment().apply {
+                commentValues.getAsLong(JtxContract.JtxComment.ID)?.let { id -> this.commentId = id }
+                commentValues.getAsString(JtxContract.JtxComment.TEXT)?.let { text -> this.text = text }
+                commentValues.getAsString(JtxContract.JtxComment.LANGUAGE)?.let { language -> this.language = language }
+                commentValues.getAsString(JtxContract.JtxComment.OTHER)?.let { other -> this.other = other }
+            }
+            comments.add(comment)
+        }
+
+        // Take care of resources
+        val resourceContentValues = getResourceContentValues()
+        resourceContentValues.forEach { resourceValues ->
+            val resource = Resource().apply {
+                resourceValues.getAsLong(JtxContract.JtxResource.ID)?.let { id -> this.resourceId = id }
+                resourceValues.getAsString(JtxContract.JtxResource.TEXT)?.let { text -> this.text = text }
+                resourceValues.getAsString(JtxContract.JtxResource.LANGUAGE)?.let { language -> this.language = language }
+                resourceValues.getAsString(JtxContract.JtxResource.OTHER)?.let { other -> this.other = other }
+            }
+            resources.add(resource)
+        }
+
+
+        // Take care of related-to
+        val relatedToContentValues = getRelatedToContentValues()
+        relatedToContentValues.forEach { relatedToValues ->
+            val relTo = RelatedTo().apply {
+                relatedToValues.getAsLong(JtxContract.JtxRelatedto.ID)?.let { id -> this.relatedtoId = id }
+                relatedToValues.getAsString(JtxContract.JtxRelatedto.TEXT)?.let { text -> this.text = text }
+                relatedToValues.getAsString(JtxContract.JtxRelatedto.RELTYPE)?.let { reltype -> this.reltype = reltype }
+                relatedToValues.getAsString(JtxContract.JtxRelatedto.OTHER)?.let { other -> this.other = other }
+
+            }
+            relatedTo.add(relTo)
+        }
+
+
+        // Take care of attendees
+        val attendeeContentValues = getAttendeesContentValues()
+        attendeeContentValues.forEach { attendeeValues ->
+            val attendee = Attendee().apply {
+                attendeeValues.getAsLong(JtxContract.JtxAttendee.ID)?.let { id -> this.attendeeId = id }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.CALADDRESS)?.let { caladdress -> this.caladdress = caladdress }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.CUTYPE)?.let { cutype -> this.cutype = cutype }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.MEMBER)?.let { member -> this.member = member }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.ROLE)?.let { role -> this.role = role }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.PARTSTAT)?.let { partstat -> this.partstat = partstat }
+                attendeeValues.getAsBoolean(JtxContract.JtxAttendee.RSVP)?.let { rsvp -> this.rsvp = rsvp }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.DELEGATEDTO)?.let { delto -> this.delegatedto = delto }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.DELEGATEDFROM)?.let { delfrom -> this.delegatedfrom = delfrom }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.SENTBY)?.let { sentby -> this.sentby = sentby }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.CN)?.let { cn -> this.cn = cn }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.DIR)?.let { dir -> this.dir = dir }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.LANGUAGE)?.let { lang -> this.language = lang }
+                attendeeValues.getAsString(JtxContract.JtxAttendee.OTHER)?.let { other -> this.other = other }
+
+            }
+            attendees.add(attendee)
+        }
+
+        // Take care of organizer
+        val organizerContentValues = getOrganizerContentValues()
+        val orgnzr = Organizer().apply {
+            organizerId = organizerContentValues?.getAsLong(JtxContract.JtxOrganizer.ID) ?: 0L
+            caladdress = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.CALADDRESS)
+            sentby = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.SENTBY)
+            cn = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.CN)
+            dir = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.DIR)
+            language = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.LANGUAGE)
+            other = organizerContentValues?.getAsString(JtxContract.JtxOrganizer.OTHER)
+        }
+        organizer = orgnzr
+
+        // Take care of attachments
+        val attachmentContentValues = getAttachmentsContentValues()
+        attachmentContentValues.forEach { attachmentValues ->
+            val attachment = Attachment().apply {
+                attachmentValues.getAsLong(JtxContract.JtxAttachment.ID)?.let { id -> this.attachmentId = id }
+                attachmentValues.getAsString(JtxContract.JtxAttachment.URI)?.let { uri -> this.uri = uri }
+                attachmentValues.getAsString(JtxContract.JtxAttachment.BINARY)?.let { value -> this.binary = value }
+                attachmentValues.getAsString(JtxContract.JtxAttachment.FMTTYPE)?.let { fmttype -> this.fmttype = fmttype }
+                attachmentValues.getAsString(JtxContract.JtxAttachment.OTHER)?.let { other -> this.other = other }
+
+            }
+            attachments.add(attachment)
+        }
+
+        // Take care of alarms
+        val alarmContentValues = getAlarmsContentValues()
+        alarmContentValues.forEach { alarmValues ->
+            val alarm = Alarm().apply {
+                alarmValues.getAsLong(JtxContract.JtxAlarm.ID)?.let { id -> this.alarmId = id }
+                alarmValues.getAsString(JtxContract.JtxAlarm.ACTION)?.let { action -> this.action = action }
+                alarmValues.getAsString(JtxContract.JtxAlarm.DESCRIPTION)?.let { desc -> this.description = desc }
+                alarmValues.getAsLong(JtxContract.JtxAlarm.TRIGGER_TIME)?.let { time -> this.triggerTime = time }
+                alarmValues.getAsString(JtxContract.JtxAlarm.TRIGGER_TIMEZONE)?.let { tz -> this.triggerTimezone = tz }
+                alarmValues.getAsString(JtxContract.JtxAlarm.TRIGGER_RELATIVE_TO)?.let { relative -> this.triggerRelativeTo = relative }
+                alarmValues.getAsString(JtxContract.JtxAlarm.TRIGGER_RELATIVE_DURATION)?.let { duration -> this.triggerRelativeDuration = duration }
+                alarmValues.getAsString(JtxContract.JtxAlarm.SUMMARY)?.let { summary -> this.summary = summary }
+                alarmValues.getAsString(JtxContract.JtxAlarm.DURATION)?.let { dur -> this.duration = dur }
+                alarmValues.getAsString(JtxContract.JtxAlarm.REPEAT)?.let { repeat -> this.repeat = repeat }
+                alarmValues.getAsString(JtxContract.JtxAlarm.ATTACH)?.let { attach -> this.attach = attach }
+                alarmValues.getAsString(JtxContract.JtxAlarm.OTHER)?.let { other -> this.other = other }
+            }
+            alarms.add(alarm)
+        }
+
+        // Take care of uknown properties
+        val unknownContentValues = getUnknownContentValues()
+        unknownContentValues.forEach { unknownValues ->
+            val unknwn = Unknown().apply {
+                unknownValues.getAsLong(JtxContract.JtxUnknown.ID)?.let { id -> this.unknownId = id }
+                unknownValues.getAsString(JtxContract.JtxUnknown.UNKNOWN_VALUE)?.let { value -> this.value = value }
+            }
+            unknown.add(unknwn)
+        }
+    }
+
+    /**
+     * Puts the current JtxICalObjects attributes into Content Values
+     * @return The JtxICalObject attributes as [ContentValues] (exluding list properties)
+     */
+    private fun toContentValues(): ContentValues {
+
+        val values = ContentValues()
+        values.put(JtxContract.JtxICalObject.ID, id)
+        summary.let { values.put(JtxContract.JtxICalObject.SUMMARY, it)  }
+        description.let { values.put(JtxContract.JtxICalObject.DESCRIPTION, it) }
+        values.put(JtxContract.JtxICalObject.COMPONENT, component)
+        status.let { values.put(JtxContract.JtxICalObject.STATUS, it) }
+        classification.let { values.put(JtxContract.JtxICalObject.CLASSIFICATION, it) }
+        priority.let { values.put(JtxContract.JtxICalObject.PRIORITY, it) }
+        values.put(JtxContract.JtxICalObject.ICALOBJECT_COLLECTIONID, collectionId)
+        values.put(JtxContract.JtxICalObject.UID, uid)
+        geoLat.let { values.put(JtxContract.JtxICalObject.GEO_LAT, it) }
+        geoLong.let { values.put(JtxContract.JtxICalObject.GEO_LONG, it) }
+        location.let { values.put(JtxContract.JtxICalObject.LOCATION, it) }
+        locationAltrep.let { values.put(JtxContract.JtxICalObject.LOCATION_ALTREP, it) }
+        percent.let { values.put(JtxContract.JtxICalObject.PERCENT, it) }
+        values.put(JtxContract.JtxICalObject.DTSTAMP, dtstamp)
+        dtstart.let { values.put(JtxContract.JtxICalObject.DTSTART, it) }
+        dtstartTimezone.let { values.put(JtxContract.JtxICalObject.DTSTART_TIMEZONE, it) }
+        dtend.let { values.put(JtxContract.JtxICalObject.DTEND, it) }
+        dtendTimezone.let { values.put(JtxContract.JtxICalObject.DTEND_TIMEZONE, it) }
+        completed.let { values.put(JtxContract.JtxICalObject.COMPLETED, it) }
+        completedTimezone.let { values.put(JtxContract.JtxICalObject.COMPLETED_TIMEZONE, it) }
+        due.let { values.put(JtxContract.JtxICalObject.DUE, it) }
+        dueTimezone.let { values.put(JtxContract.JtxICalObject.DUE_TIMEZONE, it) }
+        duration.let { values.put(JtxContract.JtxICalObject.DURATION, it) }
+
+        rrule.let { values.put(JtxContract.JtxICalObject.RRULE, it) }
+        rdate.let { values.put(JtxContract.JtxICalObject.RDATE, it) }
+        exdate.let { values.put(JtxContract.JtxICalObject.EXDATE, it) }
+        recurid.let { values.put(JtxContract.JtxICalObject.RECURID, it) }
+
+        fileName.let { values.put(JtxContract.JtxICalObject.FILENAME, it) }
+        eTag.let { values.put(JtxContract.JtxICalObject.ETAG, it) }
+        scheduleTag.let { values.put(JtxContract.JtxICalObject.SCHEDULETAG, it) }
+        values.put(JtxContract.JtxICalObject.FLAGS, flags)
+
+        return values
+    }
+
+
+    /**
+     * @return The categories of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getCategoryContentValues(): List<ContentValues> {
+
+        val categoryUrl = JtxContract.JtxCategory.CONTENT_URI.asSyncAdapter(collection.account)
+        val categoryValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            categoryUrl,
+            null,
+            "${JtxContract.JtxCategory.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                categoryValues.add(cursor.toValues())
+            }
+        }
+        return categoryValues
+    }
+
+
+    /**
+     * @return The comments of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getCommentContentValues(): List<ContentValues> {
+
+        val commentUrl = JtxContract.JtxComment.CONTENT_URI.asSyncAdapter(collection.account)
+        val commentValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            commentUrl,
+            null,
+            "${JtxContract.JtxComment.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                commentValues.add(cursor.toValues())
+            }
+        }
+        return commentValues
+    }
+
+    /**
+     * @return The resources of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getResourceContentValues(): List<ContentValues> {
+
+        val resourceUrl = JtxContract.JtxResource.CONTENT_URI.asSyncAdapter(collection.account)
+        val resourceValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            resourceUrl,
+            null,
+            "${JtxContract.JtxResource.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                resourceValues.add(cursor.toValues())
+            }
+        }
+        return resourceValues
+    }
+
+    /**
+     * @return The RelatedTo of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getRelatedToContentValues(): List<ContentValues> {
+
+        val relatedToUrl = JtxContract.JtxRelatedto.CONTENT_URI.asSyncAdapter(collection.account)
+        val relatedToValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            relatedToUrl,
+            null,
+            "${JtxContract.JtxRelatedto.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                relatedToValues.add(cursor.toValues())
+            }
+        }
+        return relatedToValues
+    }
+
+    /**
+     * @return The attendees of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getAttendeesContentValues(): List<ContentValues> {
+
+        val attendeesUrl = JtxContract.JtxAttendee.CONTENT_URI.asSyncAdapter(collection.account)
+        val attendeesValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            attendeesUrl,
+            null,
+            "${JtxContract.JtxAttendee.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                attendeesValues.add(cursor.toValues())
+            }
+        }
+        return attendeesValues
+    }
+
+    /**
+     * @return The organizer of the given JtxICalObject as ContentValues
+     */
+    private fun getOrganizerContentValues(): ContentValues? {
+
+        val organizerUrl = JtxContract.JtxOrganizer.CONTENT_URI.asSyncAdapter(collection.account)
+        collection.client.query(
+            organizerUrl,
+            null,
+            "${JtxContract.JtxOrganizer.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            if(cursor.moveToFirst()) {
+                return cursor.toValues()
+            }
+        }
+        return null
+    }
+
+    /**
+     * @return The attachments of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getAttachmentsContentValues(): List<ContentValues> {
+
+        val attachmentsUrl =
+            JtxContract.JtxAttachment.CONTENT_URI.asSyncAdapter(collection.account)
+        val attachmentsValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            attachmentsUrl,
+            null,
+            "${JtxContract.JtxAttachment.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                attachmentsValues.add(cursor.toValues())
+            }
+        }
+        return attachmentsValues
+    }
+
+    /**
+     * @return The alarms of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getAlarmsContentValues(): List<ContentValues> {
+
+        val alarmsUrl =
+            JtxContract.JtxAlarm.CONTENT_URI.asSyncAdapter(collection.account)
+        val alarmValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            alarmsUrl,
+            null,
+            "${JtxContract.JtxAlarm.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                alarmValues.add(cursor.toValues())
+            }
+        }
+        return alarmValues
+    }
+
+    /**
+     * @return The unknown properties of the given JtxICalObject as a list of ContentValues
+     */
+    private fun getUnknownContentValues(): List<ContentValues> {
+
+        val unknownUrl =
+            JtxContract.JtxUnknown.CONTENT_URI.asSyncAdapter(collection.account)
+        val unknownValues: MutableList<ContentValues> = mutableListOf()
+        collection.client.query(
+            unknownUrl,
+            null,
+            "${JtxContract.JtxUnknown.ICALOBJECT_ID} = ?",
+            arrayOf(this.id.toString()),
+            null
+        )?.use { cursor ->
+            while (cursor.moveToNext()) {
+                unknownValues.add(cursor.toValues())
+            }
+        }
+        return unknownValues
+    }
+}
diff --git a/src/main/java/at/bitfire/ical4android/JtxICalObjectFactory.kt b/src/main/java/at/bitfire/ical4android/JtxICalObjectFactory.kt
new file mode 100644
index 0000000..8f6648c
--- /dev/null
+++ b/src/main/java/at/bitfire/ical4android/JtxICalObjectFactory.kt
@@ -0,0 +1,13 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.bitfire.ical4android
+
+import android.content.ContentValues
+
+interface JtxICalObjectFactory<out T: JtxICalObject> {
+
+    fun fromProvider(collection: JtxCollection<JtxICalObject>, values: ContentValues): T
+
+}
\ No newline at end of file
diff --git a/src/main/java/at/bitfire/ical4android/MiscUtils.kt b/src/main/java/at/bitfire/ical4android/MiscUtils.kt
index a9a91ec..2b0e57d 100644
--- a/src/main/java/at/bitfire/ical4android/MiscUtils.kt
+++ b/src/main/java/at/bitfire/ical4android/MiscUtils.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/Task.kt b/src/main/java/at/bitfire/ical4android/Task.kt
index 6e84a0f..0e70ca0 100644
--- a/src/main/java/at/bitfire/ical4android/Task.kt
+++ b/src/main/java/at/bitfire/ical4android/Task.kt
@@ -1,12 +1,6 @@
-/*
- * Copyright © Ricki Hirner and contributors (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- *
- * Contributors: Alex Baker
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/main/java/at/bitfire/ical4android/TaskProvider.kt b/src/main/java/at/bitfire/ical4android/TaskProvider.kt
index da8dd38..108875f 100644
--- a/src/main/java/at/bitfire/ical4android/TaskProvider.kt
+++ b/src/main/java/at/bitfire/ical4android/TaskProvider.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
@@ -35,7 +31,8 @@ class TaskProvider private constructor(
             private val writePermission: String
     ) {
         OpenTasks("org.dmfs.tasks", "org.dmfs.tasks", 103, "1.1.8.2", PERMISSION_OPENTASKS_READ, PERMISSION_OPENTASKS_WRITE),
-        TasksOrg("org.tasks.opentasks", "org.tasks", 100000, "10.0", PERMISSION_TASKS_ORG_READ, PERMISSION_TASKS_ORG_WRITE);
+        TasksOrg("org.tasks.opentasks", "org.tasks", 100000, "10.0", PERMISSION_TASKS_ORG_READ, PERMISSION_TASKS_ORG_WRITE),
+        JtxBoard("at.techbee.jtx.provider", "at.techbee.jtx", 1, "0.1", PERMISSION_JTX_READ, PERMISSION_JTX_WRITE);
 
         companion object {
             fun fromAuthority(authority: String): ProviderName {
@@ -54,7 +51,8 @@ class TaskProvider private constructor(
 
         val TASK_PROVIDERS = listOf(
                 ProviderName.OpenTasks,
-                ProviderName.TasksOrg
+                ProviderName.TasksOrg,
+                ProviderName.JtxBoard
         )
 
         const val PERMISSION_OPENTASKS_READ = "org.dmfs.permission.READ_TASKS"
@@ -65,6 +63,10 @@ class TaskProvider private constructor(
         const val PERMISSION_TASKS_ORG_WRITE = "org.tasks.permission.WRITE_TASKS"
         val PERMISSIONS_TASKS_ORG = arrayOf(PERMISSION_TASKS_ORG_READ, PERMISSION_TASKS_ORG_WRITE)
 
+        const val PERMISSION_JTX_READ = "at.techbee.jtx.permission.READ"
+        const val PERMISSION_JTX_WRITE = "at.techbee.jtx.permission.WRITE"
+        val PERMISSIONS_JTX = arrayOf(PERMISSION_JTX_READ, PERMISSION_JTX_WRITE)
+
         /**
          * Acquires a content provider for a given task provider. The content provider will
          * be released when the TaskProvider is closed with [close].
diff --git a/src/main/java/at/bitfire/ical4android/UnknownProperty.kt b/src/main/java/at/bitfire/ical4android/UnknownProperty.kt
index 2ffad4a..f1fba04 100644
--- a/src/main/java/at/bitfire/ical4android/UnknownProperty.kt
+++ b/src/main/java/at/bitfire/ical4android/UnknownProperty.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import android.content.ContentResolver
diff --git a/src/main/java/at/bitfire/ical4android/UsesThreadContextClassLoader.kt b/src/main/java/at/bitfire/ical4android/UsesThreadContextClassLoader.kt
index 68f1093..8bc96ba 100644
--- a/src/main/java/at/bitfire/ical4android/UsesThreadContextClassLoader.kt
+++ b/src/main/java/at/bitfire/ical4android/UsesThreadContextClassLoader.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 @Target(AnnotationTarget.CLASS, AnnotationTarget.CONSTRUCTOR, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY)
diff --git a/src/main/java/at/bitfire/ical4android/util/AndroidTimeUtils.kt b/src/main/java/at/bitfire/ical4android/util/AndroidTimeUtils.kt
index 1a9c1b2..e0c8c11 100644
--- a/src/main/java/at/bitfire/ical4android/util/AndroidTimeUtils.kt
+++ b/src/main/java/at/bitfire/ical4android/util/AndroidTimeUtils.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 @file:Suppress("DEPRECATION")
 
 package at.bitfire.ical4android.util
diff --git a/src/main/java/at/bitfire/ical4android/util/TimeApiExtensions.kt b/src/main/java/at/bitfire/ical4android/util/TimeApiExtensions.kt
index af9e407..f9b1ac1 100644
--- a/src/main/java/at/bitfire/ical4android/util/TimeApiExtensions.kt
+++ b/src/main/java/at/bitfire/ical4android/util/TimeApiExtensions.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android.util
 
 import at.bitfire.ical4android.DateUtils
diff --git a/src/main/java/at/techbee/jtx/JtxContract.kt b/src/main/java/at/techbee/jtx/JtxContract.kt
new file mode 100644
index 0000000..ce1f42e
--- /dev/null
+++ b/src/main/java/at/techbee/jtx/JtxContract.kt
@@ -0,0 +1,1409 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
+package at.techbee.jtx
+
+import android.accounts.Account
+import android.net.Uri
+import android.provider.BaseColumns
+import android.util.Log
+import at.bitfire.ical4android.Ical4Android
+import net.fortuna.ical4j.model.ParameterList
+import net.fortuna.ical4j.model.Property
+import net.fortuna.ical4j.model.PropertyList
+import net.fortuna.ical4j.model.parameter.XParameter
+import net.fortuna.ical4j.model.property.XProperty
+import org.json.JSONObject
+import java.util.logging.Level
+
+@Suppress("unused")
+object JtxContract {
+
+    /**
+     * URI parameter to signal that the caller is a sync adapter.
+     */
+    const val CALLER_IS_SYNCADAPTER = "caller_is_syncadapter"
+
+    /**
+     * URI parameter to submit the account name of the account we operate on.
+     */
+    const val ACCOUNT_NAME = "account_name"
+
+    /**
+     * URI parameter to submit the account type of the account we operate on.
+     */
+    const val ACCOUNT_TYPE = "account_type"
+
+    /** The authority under which the content provider can be accessed */
+    const val AUTHORITY = "at.techbee.jtx.provider"
+
+    /** The version of this SyncContentProviderContract */
+    const val VERSION = 1
+
+    /** Constructs an Uri for the Jtx Sync Adapter with the given Account
+     * @param [account] The account that should be appended to the Base Uri
+     * @return [Uri] with the appended Account
+     */
+    fun Uri.asSyncAdapter(account: Account): Uri =
+        buildUpon()
+            .appendQueryParameter(CALLER_IS_SYNCADAPTER, "true")
+            .appendQueryParameter(ACCOUNT_NAME, account.name)
+            .appendQueryParameter(ACCOUNT_TYPE, account.type)
+            .build()
+
+    /**
+     * This function takes a string and tries to parse it to a list of XParameters.
+     * This is the counterpart of getJsonStringFromXParameters(...)
+     * @param [string] that should be parsed
+     * @return The list of XParameter parsed from the string
+     */
+    fun getXParametersFromJson(string: String): List<XParameter> {
+        val jsonObject = JSONObject(string)
+        val xparamList = mutableListOf<XParameter>()
+        for (i in 0 until jsonObject.length()) {
+            val names = jsonObject.names() ?: break
+            val xparamName = names[i]?.toString() ?: break
+            val xparamValue = jsonObject.getString(xparamName).toString()
+            if (xparamName.isNotBlank() && xparamValue.isNotBlank()) {
+                val xparam = XParameter(xparamName, xparamValue)
+                xparamList.add(xparam)
+            }
+        }
+        return xparamList
+    }
+
+    /**
+     * This function takes a string and tries to parse it to a list of XProperty.
+     * This is the counterpart of getJsonStringFromXProperties(...)
+     * @param [string] that should be parsed
+     * @return The list of XProperty parsed from the string
+     */
+    fun getXPropertyListFromJson(string: String): PropertyList<Property> {
+        val propertyList = PropertyList<Property>()
+
+        if (string.isBlank())
+            return propertyList
+
+        try {
+            val jsonObject = JSONObject(string)
+            for (i in 0 until jsonObject.length()) {
+                val names = jsonObject.names() ?: break
+                val propertyName = names[i]?.toString() ?: break
+                val propertyValue = jsonObject.getString(propertyName).toString()
+                if (propertyName.isNotBlank() && propertyValue.isNotBlank()) {
+                    val prop = XProperty(propertyName, propertyValue)
+                    propertyList.add(prop)
+                }
+            }
+        } catch (e: NullPointerException) {
+            Ical4Android.log.log(Level.WARNING, "Error parsing x-property-list $string", e)
+        }
+        return propertyList
+    }
+
+
+    /**
+     * Takes a Parameter List and returns a Json String to be saved in a DB field.
+     * This is the counterpart to getXParameterFromJson(...)
+     * @param [parameters] The ParameterList that should be transformed into a Json String
+     * @return The generated Json object as a [String]
+     */
+    fun getJsonStringFromXParameters(parameters: ParameterList?): String? {
+        if (parameters == null)
+            return null
+
+        val jsonObject = JSONObject()
+        parameters.forEach { parameter ->
+            jsonObject.put(parameter.name, parameter.value)
+        }
+        return if (jsonObject.length() == 0)
+            null
+        else
+            jsonObject.toString()
+    }
+
+    /**
+     * Takes a Property List and returns a Json String to be saved in a DB field.
+     * This is the counterpart to getXPropertyListFromJson(...)
+     * @param [propertyList] The PropertyList that should be transformed into a Json String
+     * @return The generated Json object as a [String]
+     */
+    fun getJsonStringFromXProperties(propertyList: PropertyList<*>?): String? {
+        if (propertyList == null)
+            return null
+
+        val jsonObject = JSONObject()
+        propertyList.forEach { property ->
+            jsonObject.put(property.name, property.value)
+        }
+        return if (jsonObject.length() == 0)
+            null
+        else
+            jsonObject.toString()
+    }
+
+
+    /**
+     * Some date fields in jtx Board are saved as a list of Long values separated by commas.
+     * This applies for example to the exdate for recurring events.
+     * This function takes a string and tries to parse it to a list of long values (timestamps)
+     * @param [string] that should be parsed
+     * @return a [MutableList<Long>] with the timestamps parsed from the string
+     *
+     */
+    fun getLongListFromString(string: String): MutableList<Long> {
+        val stringList = string.split(",")
+        val longList = mutableListOf<Long>()
+
+        stringList.forEach {
+            try {
+                longList.add(it.toLong())
+            } catch (e: NumberFormatException) {
+                Ical4Android.log.log(Level.WARNING, "String could not be cast to Long ($it)")
+                return@forEach
+            }
+        }
+        return longList
+    }
+
+
+    @Suppress("unused")
+    object JtxICalObject {
+
+        /** The name of the the content URI for IcalObjects.
+         * This is a general purpose table containing general columns
+         * for Journals, Notes and Todos */
+        private const val CONTENT_URI_PATH = "icalobject"
+
+        /** The content uri of the ICalObject table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+        /** Constant to define all day values (for dtstart, due, completed timezone fields */
+        const val TZ_ALLDAY = "ALLDAY"
+
+        /** The name of the ID column.
+         * This is the unique identifier of an ICalObject.
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The column for the module.
+         * This is an internal differentiation for JOURNAL, NOTE and TODO as provided in the enum [Module].
+         * The Module does not need to be set. On import it will be derived from the component from the [Component] (Todo or Journal/Note) and if a
+         * dtstart is present or not (Journal or Note). If the module was set, it might be overwritten on import. In this sense also
+         * unknown values are overwritten.
+         * Use e.g. Module.JOURNAL.name for a correct String value in this field.
+         * Type: [String]
+         */
+        const val MODULE = "module"
+
+        /***** The names of all the other columns  *****/
+        /** The column for the component based on the values provided in the enum [Component].
+         * Use e.g. Component.VTODO.name for a correct String value in this field.
+         * If no Component is provided on Insert, an IllegalArgumentException is thrown
+         * Type: [String]
+         */
+        const val COMPONENT = "component"
+
+        /**
+         * Purpose:  This column/property defines a short summary or subject for the calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.12]
+         * Type: [String]
+         */
+        const val SUMMARY = "summary"
+
+        /**
+         * Purpose:  This column/property provides a more complete description of the calendar component than that provided by the "SUMMARY" property.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.5]
+         * Type: [String]
+         */
+        const val DESCRIPTION = "description"
+
+        /**
+         * Purpose:  This column/property specifies when the calendar component begins.
+         * This value is stored as UNIX timestamp (milliseconds).
+         * The corresponding timezone is stored in [DTSTART_TIMEZONE].
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.4]
+         * Type: [Long]
+         */
+        const val DTSTART = "dtstart"
+
+        /**
+         * Purpose:  This column/property specifies the timezone of when the calendar component begins.
+         * The corresponding datetime is stored in [DTSTART].
+         * The value of a timezone can be:
+         * 1. the id of a Java timezone to represent the given timezone.
+         * 2. null to represent floating time.
+         * 3. the value of [TZ_ALLDAY] to represent an all-day entry.
+         * If an invalid value is passed, the Timezone is ignored and interpreted as UTC.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.4]
+         * Type: [String]
+         */
+        const val DTSTART_TIMEZONE = "dtstarttimezone"
+
+        /**
+         * Purpose:  This column/property specifies when the calendar component ends.
+         * This value is stored as UNIX timestamp (milliseconds).
+         * The corresponding timezone is stored in [DTEND_TIMEZONE].
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.4]
+         * Type: [Long]
+         */
+        const val DTEND = "dtend"
+
+        /**
+         * Purpose:  This column/property specifies the timezone of when the calendar component ends.
+         * The corresponding datetime is stored in [DTEND].
+         * See [DTSTART_TIMEZONE] for information about the timezone handling
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.2]
+         * Type: [String]
+         */
+        const val DTEND_TIMEZONE = "dtendtimezone"
+
+        /**
+         * Purpose:  This property defines the overall status or confirmation for the calendar component.
+         * The possible values of a status are defined in [StatusTodo] for To-Dos and in [StatusJournal] for Notes and Journals
+         * If no valid Status is used, the value is taken and will be shown as-is.
+         * Also null-value is allowed.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.11]
+         * Type: [String]
+         */
+        const val STATUS = "status"
+
+        /**
+         * Purpose:  This property defines the access classification for a calendar component.
+         * The possible values of a status are defined in the enum [Classification].
+         * Use e.g. Classification.PUBLIC.name to put a correct String value in this field.
+         * If no valid Classification is used, the value is taken and will be shown as-is.
+         * Also null-value is allowed.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.11]
+         * Type: [String]
+         */
+        const val CLASSIFICATION = "classification"
+
+        /**
+         * Purpose:  This property defines a Uniform Resource Locator (URL) associated with the iCalendar object.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.4.6]
+         * Type: [String]
+         */
+        const val URL = "url"
+
+        /**
+         * Purpose:  This property is used to represent contact information or alternately a reference
+         * to contact information associated with the calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.4.2]
+         * Type: [String]
+         */
+        const val CONTACT = "contact"
+
+        /**
+         * Purpose:  This property specifies information related to the global position for the activity specified by a calendar component.
+         * This property is split in the fields [GEO_LAT] for the latitude
+         * and [GEO_LONG] for the longitude coordinates using the WGS84 ellipsoid.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.6]
+         * Type: [Float]
+         */
+        const val GEO_LAT = "geolat"
+
+        /**
+         * Purpose:  This property specifies information related to the global position for the activity specified by a calendar component.
+         * This property is split in the fields [GEO_LAT] for the latitude
+         * and [GEO_LONG] for the longitude coordinates using the WGS84 ellipsoid.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.6]
+         * Type: [Double]
+         */
+        const val GEO_LONG = "geolong"
+
+        /**
+         * Purpose:  This property defines the intended venue for the activity defined by a calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.7]
+         * Type: [Double]
+         */
+        const val LOCATION = "location"
+
+        /**
+         * Purpose:  This property defines the alternative representation of the intended venue for the activity defined by a calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.7]
+         * Type: [String]
+         */
+        const val LOCATION_ALTREP = "locationaltrep"
+
+        /**
+         * Purpose:  This property is used by an assignee or delegatee of a to-do to convey the percent completion of a to-do to the "Organizer".
+         * The value must either be null or between 0 and 100. The value 0 is interpreted as null.
+         * If a value outside of the boundaries (0-100) is passed, the value is reset to null.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.8]
+         * Type: [Int]
+         */
+        const val PERCENT = "percent"
+
+        /**
+         * Purpose:  This property defines the relative priority for a calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.1.9]. The priority can be null or between 0 and 9.
+         * Values outside of these boundaries are accepted but internally not mapped to a string resource.
+         * Type: [Int]
+         */
+        const val PRIORITY = "priority"
+
+        /**
+         * Purpose:  This property defines the date and time that a to-do is expected to be completed.
+         * This value is stored as UNIX timestamp (milliseconds).
+         * The corresponding timezone is stored in [DUE_TIMEZONE].
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.3]
+         * Type: [Long]
+         */
+        const val DUE = "due"
+
+        /**
+         * Purpose:  This column/property specifies the timezone of when a to-do is expected to be completed.
+         * The corresponding datetime is stored in [DUE].
+         * See [DTSTART_TIMEZONE] for information about the timezone handling
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.2]
+         * Type: [String]
+         */
+        const val DUE_TIMEZONE = "duetimezone"
+
+        /**
+         * Purpose:  This property defines the date and time that a to-do was actually completed.
+         * This value is stored as UNIX timestamp (milliseconds).
+         * The corresponding timezone is stored in [COMPLETED_TIMEZONE].
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.1]
+         * Type: [Long]
+         */
+        const val COMPLETED = "completed"
+
+        /**
+         * Purpose:  This column/property specifies the timezone of when a to-do was actually completed.
+         * The corresponding datetime is stored in [COMPLETED].
+         * See [DTSTART_TIMEZONE] for information about the timezone handling
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.1]
+         * Type: [String]
+         */
+        const val COMPLETED_TIMEZONE = "completedtimezone"
+
+        /**
+         * Purpose:  This property specifies a positive duration of time.
+         * See [DTSTART_TIMEZONE] for information about the timezone handling
+         * The string representation follows the notation as given in RFC-5545
+         * for the value type duration: [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.6]
+         * Exampe: "P15DT5H0M20S". This field is currently not in use. If present, the user would
+         * see a notification that a duration cannot be processed and will be overwritten if the entry is changed.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.5]
+         * Type: [String]
+         */
+        const val DURATION = "duration"
+
+
+        /**
+         * Purpose:  This property defines a rule or repeating pattern for recurring events,
+         * to-dos, journal entries, or time zone definitions.
+         * The representation of the RRULE follows the value type RECUR of RFC-5545 as given in
+         * [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.10]
+         * For example: "FREQ=DAILY;COUNT=10"
+         * See also [https://datatracker.ietf.org/doc/html/rfc5545#section-3.8.5.3].
+         * Type: [String]
+         */
+        const val RRULE = "rrule"
+
+        /**
+         * Purpose:  This property defines the list of DATE-TIME values for
+         * recurring events, to-dos, journal entries, or time zone definitions.
+         * Type: [String], contains a list of comma-separated date values as
+         * UNIX timestamps (milliseconds) e.g. "1636751475000,1636837875000".
+         * Invalid values that cannot be transformed to [Long] are ignored.
+         */
+        const val RDATE = "rdate"
+
+        /**
+         * Purpose:  This property defines the list of DATE-TIME exceptions for
+         * recurring events, to-dos, journal entries, or time zone definitions.
+         * Type: [String], contains a list of comma-separated date values as
+         * UNIX timestamps (milliseconds) e.g. "1636751475000,1636837875000".
+         * Invalid values that cannot be transformed to [Long] are ignored.
+         */
+        const val EXDATE = "exdate"
+
+        /**
+         * Purpose:  This property is used in conjunction with the "UID" and
+         * "SEQUENCE" properties to identify a specific instance of a
+         * recurring "VEVENT", "VTODO", or "VJOURNAL" calendar component.
+         * The property value is the original value of the "DTSTART" property
+         * of the recurrence instance, ie. a DATE or DATETIME value e.g. "20211101T160000".
+         * Must be null for non-recurring and original events from which recurring events are derived.
+         * Type: [String]
+         */
+        const val RECURID = "recurid"
+
+        /**
+         * Stores the reference to the original event from which the recurring event was derived.
+         * This value is NULL for the orignal event or if the event is not recurring
+         * Type: [Long], References [JtxICalObject.ID]
+         */
+        const val RECUR_ORIGINALICALOBJECTID = "original_id"
+
+        /**
+         * Purpose:  This property defines the persistent, globally unique identifier for the calendar component.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.4.7]
+         * Type: [String]
+         */
+        const val UID = "uid"
+
+        /**
+         * Purpose:  This property specifies the date and time that the calendar information
+         * was created by the calendar user agent in the calendar store and is stored as UNIX timestamp (milliseconds).
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.7.1]
+         * Type: [Long]
+         */
+        const val CREATED = "created"
+
+        /**
+         * Purpose:  In the case of an iCalendar object that specifies a
+         * "METHOD" property, this property specifies the date and time that
+         * the instance of the iCalendar object was created.  In the case of
+         * an iCalendar object that doesn't specify a "METHOD" property, this
+         * property specifies the date and time that the information
+         * associated with the calendar component was last revised in the
+         * calendar store. It is saved as UNIX timestamp (milliseconds).
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.7.2]
+         * Type: [Long]
+         */
+        const val DTSTAMP = "dtstamp"
+
+        /**
+         * Purpose:  This property specifies the date and time that the information associated
+         * with the calendar component was last revised in the calendar store.
+         * It is saved as UNIX timestamp (milliseconds).
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.7.3]
+         * Type: [Long]
+         */
+        const val LAST_MODIFIED = "lastmodified"
+
+        /**
+         * Purpose:  This property defines the revision sequence number of the calendar component within a sequence of revisions.
+         * If no sequence is present, it is automatically initialized with 0
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.7.4]
+         * Type: [Int]
+         */
+        const val SEQUENCE = "sequence"
+
+        /**
+         * Purpose:  This property specifies a color used for displaying the calendar, event, todo, or journal data.
+         * See [https://tools.ietf.org/html/rfc7986#section-5.9].
+         * The color is represented as Int-value as described in [https://developer.android.com/reference/android/graphics/Color#color-ints]
+         * Type: [Int]
+         */
+        const val COLOR = "color"
+
+        /**
+         * Purpose:  This column is the foreign key to the [JtxCollection].
+         * Type: [Long], references [JtxCollection.ID]
+         */
+        const val ICALOBJECT_COLLECTIONID = "collectionId"
+
+        /**
+         * Purpose:  This column defines if the local ICalObject was changed and that it is supposed to be synchronised.
+         * Type: [Boolean]
+         */
+        const val DIRTY = "dirty"
+
+        /**
+         * Purpose:  This column defines if a collection that is supposed to be synchonized was locally marked as deleted.
+         * Type: [Boolean]
+         */
+        const val DELETED = "deleted"
+
+        /**
+         * Purpose:  The remote file name of the synchronized entry (*.ics), only relevant for synchronized
+         * entries through the sync-adapter
+         * Type: [String]
+         */
+        const val FILENAME = "filename"
+
+        /**
+         * Purpose:  eTag for SyncAdapter, only relevant for synched entries through sync-adapter
+         * Type: [String]
+         */
+        const val ETAG = "etag"
+
+        /**
+         * Purpose:  scheduleTag for SyncAdapter, only relevant for synched entries through sync-adapter
+         * Type: [String]
+         */
+        const val SCHEDULETAG = "scheduletag"
+
+        /**
+         * Purpose:  flags for SyncAdapter, only relevant for synched entries through sync-adapter
+         * Type: [Int]
+         */
+        const val FLAGS = "flags"
+
+        /**
+         * Purpose:  To specify other properties for the ICalObject.
+         * This is especially used for additional properties that cannot be put into another field, especially relevant for the synchronization
+         * The Properties are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXProperties(PropertyList<*> that returns a Json String from the property list
+         * to be stored in this other field. The counterpart to this function is
+         * getXPropertyListFromJson(String) that returns a PropertyList from a Json that was created with getJsonStringFromXProperties()
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+
+        /**
+         * This enum class defines the possible values for the attribute status of an [JtxICalObject] for Journals/Notes
+         *  Use its name when the string representation is required, e.g. StatusJournal.DRAFT.name.
+         */
+        enum class StatusJournal {
+            DRAFT, FINAL, CANCELLED
+        }
+
+        /**
+         * This enum class defines the possible values for the attribute status of an [JtxICalObject] for Todos
+         * Use its name when the string representation is required, e.g. StatusTodo.`NEEDS-ACTION`.name.
+         */
+        enum class StatusTodo {
+            `NEEDS-ACTION`, COMPLETED, `IN-PROCESS`, CANCELLED
+        }
+
+        /**
+         * This enum class defines the possible values for the attribute classification of an [JtxICalObject]
+         * Use its name when the string representation is required, e.g. Classification.PUBLIC.name.
+         */
+        enum class Classification {
+            PUBLIC, PRIVATE, CONFIDENTIAL
+        }
+
+        /**
+         * This enum class defines the possible values for the attribute component of an [JtxICalObject]
+         * Use its name when the string representation is required, e.g. Component.VJOURNAL.name.
+         */
+        enum class Component {
+            VJOURNAL, VTODO
+        }
+
+        /**
+         * This enum class defines the possible values for the attribute module of an [JtxICalObject]
+         * Use its name when the string representation is required, e.g. Module.JOURNAL.name.
+         */
+        enum class Module {
+            JOURNAL, NOTE, TODO
+        }
+    }
+
+
+    @Suppress("unused")
+    object JtxAttendee {
+
+        /** The name of the the table for Attendees that are linked to an ICalObject.
+         *  [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] */
+        private const val CONTENT_URI_PATH = "attendee"
+
+        /** The content uri of the Attendee table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column.
+         * This is the unique identifier of an Attendee
+         * Type: [Long] */
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This value type is used to identify properties that contain a calendar user address (in this case of the attendee).
+         * This is usually an e-mail address as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3].
+         * The value should be passed as String containing the URI with "mailto:", for example: "mailto:jane_doe@example.com"
+         * See also [https://tools.ietf.org/html/rfc5545#section-3.8.4.1].
+         * Type: [String]
+         */
+        const val CALADDRESS = "caladdress"
+
+        /**
+         * Purpose:  To identify the type of calendar user specified by the property in this case for the attendee.
+         * The possible values are defined in the enum [Cutype].
+         * Use e.g. Cutype.INDIVIDUAL.name to put a correct String value in this field.
+         * If no value is passed for the Cutype, the Cutype will be interpreted as INDIVIDUAL as according to the RFC.
+         * Other values are accepted and treated as UNKNOWN.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.3]
+         * Type: [String]
+         */
+        const val CUTYPE = "cutype"
+
+        /**
+         * Purpose:  To specify the group or list membership of the calendar user specified by the property in this case for the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.11]
+         * Type: [String]
+         */
+        const val MEMBER = "member"
+
+        /**
+         * Purpose:  To specify the participation role for the calendar user specified by the property in this case for the attendee.
+         * The possible values are defined in the enum [Role]
+         * Use e.g. Role.CHAIR.name to put a correct String value in this field.
+         * If no value (null) is passed for the Role, it will be interpreted as REQ-PARTICIPANT as according to the RFC.
+         * Other values are accepted and treated as REQ-PARTICIPANTs.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.16]
+         * Type: [String]
+         */
+        const val ROLE = "role"
+
+        /**
+         * Purpose:  To specify the participation status for the calendar user specified by the property in this case for the attendee.
+         * The possible values are defined in the enum [PartstatJournal] and [PartstatTodo]
+         * Use e.g. PartstatJournal.ACCEPTED.name to put a correct String value in this field.
+         * If no value (null) is passed for the Partstat, it will be interpreted as NEEDS-ACTION as according to the RFC.
+         * Other values are accepted and treated as NEEDS-ACTION.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.12]
+         * Type: [String]
+         */
+        const val PARTSTAT = "partstat"
+
+        /**
+         * Purpose:  To specify whether there is an expectation of a favor of a reply from the calendar user specified by the property value
+         * in this case for the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.17]
+         * Type: [Boolean]
+         */
+        const val RSVP = "rsvp"
+
+        /**
+         * Purpose:  To specify the calendar users to whom the calendar user specified by the property
+         * has delegated participation in this case for the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.5]
+         * Type: [String]
+         */
+        const val DELEGATEDTO = "delegatedto"
+
+        /**
+         * Purpose:  To specify the calendar users that have delegated their participation to the calendar user specified by the property
+         * in this case for the attendee.
+         * This is usually an e-mail address as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3].
+         * The value should be passed as String containing the URI with "mailto:", for example: "mailto:jane_doe@example.com"
+         * See also [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.4]
+         * Type: [String]
+         */
+        const val DELEGATEDFROM = "delegatedfrom"
+
+        /**
+         * Purpose:  To specify the calendar user that is acting on behalf of the calendar user specified by the property in this case for the attendee.
+         * This is usually an e-mail address as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3].
+         * The value should be passed as String containing the URI with "mailto:", for example: "mailto:jane_doe@example.com"
+         * See also [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.18]
+         * Type: [String]
+         */
+        const val SENTBY = "sentby"
+
+        /**
+         * Purpose:  To specify the common name to be associated with the calendar user specified by the property in this case for the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.2]
+         * Type: [String]
+         */
+        const val CN = "cn"
+
+        /**
+         * Purpose:  To specify reference to a directory entry associated with the calendar user specified by the property in this case for the attendee.
+         * Expected is an URI as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.6].
+         * The value should be passed as String, e.g. "ldap://example.com:6666/o=ABC%20Industries,c=US???(cn=Jim%20Dolittle)"
+         * Type: [String]
+         */
+        const val DIR = "dir"
+
+        /**
+         * Purpose:  To specify the language for text values in a property or property parameter, in this case of the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1] and [https://tools.ietf.org/html/rfc5545#section-3.2.10]
+         * Language-Tag as defined in RFC5646, e.g. "en:Germany"
+         * Type: [String]
+         */
+        const val LANGUAGE = "language"
+
+        /**
+         * Purpose:  To specify other parameters for the attendee.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.1]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+
+        /**
+         * This enum class defines the possible values for the attribute Cutype of an [JtxAttendee]
+         * Use its name when the string representation is required, e.g. Cutype.INDIVIDUAL.name.
+         */
+        enum class Cutype {
+            INDIVIDUAL, GROUP, RESOURCE, ROOM, UNKNOWN
+        }
+
+        /**
+         * This enum class defines the possible values for the attribute Role of an [JtxAttendee]
+         * Use its name when the string representation is required, e.g. Role.`REQ-PARTICIPANT`.name.
+         */
+        enum class Role {
+            CHAIR, `REQ-PARTICIPANT`, `OPT-PARTICIPANT`, `NON-PARTICIPANT`
+        }
+
+        /** This enum class defines the possible values for the attribute [JtxAttendee] for the Component VJOURNAL  */
+        @Suppress("unused")
+        enum class PartstatJournal {
+            `NEEDS-ACTION`, ACCEPTED, DECLINED
+        }
+
+        /** This enum class defines the possible values for the attribute [JtxAttendee] for the Component VTODO  */
+        @Suppress("unused")
+        enum class PartstatTodo {
+            `NEEDS-ACTION`, ACCEPTED, DECLINED, TENTATIVE, DELEGATED, COMPLETED, `IN-PROCESS`
+        }
+    }
+
+    @Suppress("unused")
+    object JtxCategory {
+
+        /** The name of the the table for Categories that are linked to an ICalObject.
+         * [https://tools.ietf.org/html/rfc5545#section-3.8.1.2]*/
+        private const val CONTENT_URI_PATH = "category"
+
+        /** The content uri of the Category table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for categories.
+         * This is the unique identifier of a Category
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property defines the name of the category for a calendar component.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.2]
+         * Type: [String]
+         */
+        const val TEXT = "text"
+
+        /**
+         * Purpose:  To specify the language for text values in a property or property parameter, in this case of the category.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.2] and [https://tools.ietf.org/html/rfc5545#section-3.2.10]
+         * Language-Tag as defined in RFC5646, e.g. "en:Germany"
+         * Type: [String]
+         */
+        const val LANGUAGE = "language"
+
+        /**
+         * Purpose:  To specify other properties for the category.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.2]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+    }
+
+    @Suppress("unused")
+    object JtxComment {
+
+        /** The name of the the table for Comments that are linked to an ICalObject.
+         * [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]*/
+        private const val CONTENT_URI_PATH = "comment"
+
+        /** The content uri of the Comment table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for comments.
+         * This is the unique identifier of a Comment
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property specifies non-processing information intended to provide a comment to the calendar user.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]
+         * Type: [String]
+         */
+        const val TEXT = "text"
+
+        /**
+         * Purpose:  To specify the language for text values in a property or property parameter, in this case of the comment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]
+         * Language-Tag as defined in RFC5646, e.g. "en:Germany"
+         * Type: [String]
+         */
+        const val ALTREP = "altrep"
+
+        /**
+         * Purpose:  To specify an alternate text representation for the property value, in this case of the comment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]
+         * Type: [String]
+         */
+        const val LANGUAGE = "language"
+
+        /**
+         * Purpose:  To specify other properties for the comment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+    }
+
+
+    @Suppress("unused")
+    object JtxOrganizer {
+        /** The name of the the table for Organizer that are linked to an ICalObject.
+         * [https://tools.ietf.org/html/rfc5545#section-3.8.4.3]
+         */
+        private const val CONTENT_URI_PATH = "organizer"
+
+        /** The content uri of the Organizer table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for the organizer.
+         * This is the unique identifier of a Organizer
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This value type is used to identify properties that contain a calendar user address (in this case of the organizer).
+         * This is usually an e-mail address as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3].
+         * The value should be passed as String containing the URI with "mailto:", for example: "mailto:jane_doe@example.com"
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3].
+         * Type: [String]
+         */
+        const val CALADDRESS = "caladdress"
+
+        /**
+         * Purpose:  To specify the common name to be associated with the calendar user specified by the property in this case for the organizer.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3] and [https://tools.ietf.org/html/rfc5545#section-3.2.18]
+         * Type: [String]
+         */
+        const val CN = "cnparam"
+
+        /**
+         * Purpose:  To specify reference to a directory entry associated with the calendar user specified by the property in this case for the organizer.
+         * Expected is an URI as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.6].
+         * The value should be passed as String, e.g. "ldap://example.com:6666/o=ABC%20Industries,c=US???(cn=Jim%20Dolittle)"
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3] and [https://tools.ietf.org/html/rfc5545#section-3.2.2]
+         * Type: [String]
+         */
+        const val DIR = "dirparam"
+
+        /**
+         * Purpose:  To specify the calendar user that is acting on behalf of the calendar user specified by the property in this case for the organizer.
+         * This is usually an e-mail address as defined in [https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3].
+         * The value should be passed as String containing the URI with "mailto:", for example: "mailto:jane_doe@example.com"
+         * See also [https://tools.ietf.org/html/rfc5545#section-3.8.4.3] and [https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.18]
+         * Type: [String]
+         */
+        const val SENTBY = "sentbyparam"
+
+        /**
+         * Purpose:  To specify the language for text values in a property or property parameter, in this case of the organizer.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3] and [https://tools.ietf.org/html/rfc5545#section-3.2.10]
+         * Language-Tag as defined in RFC5646, e.g. "en:Germany"
+         * Type: [String]
+         */
+        const val LANGUAGE = "language"
+
+        /**
+         * Purpose:  To specify other properties for the organizer.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+
+    }
+
+    @Suppress("unused")
+    object JtxRelatedto {
+
+        /** The name of the the table for Relationships (related-to) that are linked to an ICalObject.
+         * [https://tools.ietf.org/html/rfc5545#section-3.8.4.5]
+         */
+        private const val CONTENT_URI_PATH = "relatedto"
+
+        /** The content uri of the relatedto table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for the related-to.
+         * This is the unique identifier of a Related-to
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+        /** The name of the second Foreign Key Column of the related IcalObject
+         * Type: [Long]
+         */
+        const val LINKEDICALOBJECT_ID = "linkedICalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property is used to represent a relationship or reference between one calendar component and another.
+         * The text gives the UID of the related calendar entry.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.5]
+         * Type: [String]
+         */
+        const val TEXT = "text"
+
+        /**
+         * Purpose:  To specify the type of hierarchical relationship associated
+         * with the calendar component specified by the property.
+         * The possible relationship types are defined in the enum [Reltype].
+         * Use e.g. Reltype.PARENT.name to put a correct String value in this field.
+         * Other values and null-values are allowed, but will not be processed by the app.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.5] and [https://tools.ietf.org/html/rfc5545#section-3.2.15]
+         * Type: [String]
+         */
+        const val RELTYPE = "reltype"
+
+        /**
+         * Purpose:  To specify other properties for the related-to.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.5]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+
+        /**
+         * This enum class defines the possible values for the attribute Reltype of an [JtxRelatedto].
+         * Use its name when the string representation is required, e.g. Reltype.PARENT.name.
+         */
+        enum class Reltype {
+            PARENT, CHILD, SIBLING
+        }
+
+    }
+
+    @Suppress("unused")
+    object JtxResource {
+        /** The name of the the table for Resources that are linked to an ICalObject.
+         * [https://tools.ietf.org/html/rfc5545#section-3.8.1.10]*/
+        private const val CONTENT_URI_PATH = "resource"
+
+        /** The content uri of the resources table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for resources.
+         * This is the unique identifier of a Resource
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property defines the name of the resource for a calendar component.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.10]
+         * Type: [String]
+         */
+        const val TEXT = "text"
+
+        /**
+         * Purpose:  To specify an alternate text representation for the property value, in this case of the resource.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.4]
+         * Language-Tag as defined in RFC5646, e.g. "en:Germany"
+         * Type: [String]
+         */
+        const val LANGUAGE = "language"
+
+        /**
+         * Purpose:  To specify other properties for the resource.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.10]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+    }
+
+    @Suppress("unused")
+    object JtxCollection {
+
+        /** The name of the the table for Collections
+         * ICalObjects MUST be linked to a collection! */
+        private const val CONTENT_URI_PATH = "collection"
+
+        /** The content uri of the collections table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+        /**
+         * Account type used for testing. This account type must be used for integrated testing.
+         * Otherwise the application would check if an account exists in the Android accounts
+         * and delete the test account/collections immediately. Using this test account prevents
+         * this behaviour for Debug builds.
+         */
+        const val TEST_ACCOUNT_TYPE = "TEST"
+
+
+        /** The name of the the table for Collections.
+         * ICalObjects MUST be linked to a collection! */
+        const val TABLE_NAME_COLLECTION = "collection"
+
+        /** The name of the ID column for collections.
+         * This is the unique identifier of a Collection
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This column/property defines the url of the collection.
+         * Type: [String]
+         */
+        const val URL = "url"
+
+        /**
+         * Purpose:  This column/property defines the display name of the collection.
+         * Type: [String]
+         */
+        const val DISPLAYNAME = "displayname"
+
+        /**
+         * Purpose:  This column/property defines a description of the collection.
+         * Type: [String]
+         */
+        const val DESCRIPTION = "description"
+
+        /**
+         * Purpose:  This column/property defines the owner of the collection.
+         * Type: [String]
+         */
+        const val OWNER = "owner"
+
+        /**
+         * Purpose:  This column/property defines the color of the collection items.
+         * This color can also be overwritten by the color in an ICalObject.
+         * The color is represented as Int-value as described in [https://developer.android.com/reference/android/graphics/Color#color-ints]
+         * Type: [Int]
+         */
+        const val COLOR = "color"
+
+        /**
+         * Purpose:  This column/property defines the if the collection supports VEVENTs.
+         * Type: [Boolean]
+         */
+        const val SUPPORTSVEVENT = "supportsVEVENT"
+
+        /**
+         * Purpose:  This column/property defines the if the collection supports VTODOs.
+         * Type: [Boolean]
+         */
+        const val SUPPORTSVTODO = "supportsVTODO"
+
+        /**
+         * Purpose:  This column/property defines the if the collection supports VJOURNALs.
+         * Type: [Boolean]
+         */
+        const val SUPPORTSVJOURNAL = "supportsVJOURNAL"
+
+        /**
+         * Purpose:  This column/property defines the if the account name under which the collection resides.
+         * Type: [String]
+         */
+        const val ACCOUNT_NAME = "accountname"
+
+        /**
+         * Purpose:  This column/property defines the if the account type under which the collection resides.
+         * Type: [String]
+         */
+        const val ACCOUNT_TYPE = "accounttype"
+
+        /**
+         * Purpose:  This column/property defines a field for the Sync Version for the Sync Adapter
+         * Type: [String]
+         */
+        const val SYNC_VERSION = "syncversion"
+
+        /**
+         * Purpose:  This column/property defines if a collection is marked as read-only by the Sync Adapter
+         * Type: [Boolean]
+         */
+        const val READONLY = "readonly"
+
+    }
+
+
+    @Suppress("unused")
+    object JtxAttachment {
+
+        /** The name of the the table for Attachments that are linked to an ICalObject.*/
+        private const val CONTENT_URI_PATH = "attachment"
+
+        /** The content uri of the resources table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for attachments.
+         * This is the unique identifier of an Attachment
+         * Type: [Long]*/
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property specifies the uri of an attachment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.1]
+         * Type: [String]
+         */
+        const val URI = "uri"
+
+        /**
+         * Purpose:  To specify the value of the attachment (binary).
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.1]
+         * Type: [String]
+         */
+        const val BINARY = "binary"
+
+        /**
+         * Purpose:  To specify the fmttype of the attachment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.1]
+         * Type: [String]
+         */
+        const val FMTTYPE = "fmttype"
+
+        /**
+         * Purpose:  To specify other properties for the attachment.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.1.1]
+         * The Parameters are stored as JSON. There are two helper functions provided:
+         * getJsonStringFromXParameters(ParameterList?) that returns a Json String from the parameter list
+         * to be stored in this other field. The counterpart to this function is
+         * getXParameterFromJson(String) that returns a list of XParameters from a Json that was created with getJsonStringFromXParameters(...)
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+    }
+
+
+    @Suppress("unused")
+    object JtxAlarm {
+
+        /** The name of the the table for Alarms that are linked to an ICalObject.*/
+        private const val CONTENT_URI_PATH = "alarm"
+
+        /** The content uri of the resources table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for attachments.
+         * This is the unique identifier of an Attachment
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+        /**
+         * Each "VALARM" calendar component has a particular type
+         * of action with which it is associated.  This property specifies
+         * the type of action.  Applications MUST ignore alarms with x-name
+         * and iana-token values they don't recognize.
+         * Currently only "DISPLAY" is supported, all other values can be stored but are ignored
+         * Type: [String]
+         */
+        const val ACTION = "action"
+
+        /**
+         * This property provides a more complete description of the
+         * calendar component than that provided by the "SUMMARY" property.
+         * Type: [String]
+         */
+        const val DESCRIPTION = "description"
+
+        /**
+         * This property defines a short summary or subject for the
+         * calendar component.
+         * Type: [String]
+         */
+        const val SUMMARY = "summary"
+
+        /**
+         * This property contains a CSV-list of attendees as Uris
+         * e.g. "mailto:contact@techbee.at,mailto:jtx@techbee.at"
+         */
+        const val ATTENDEE = "attendee"
+
+        /**
+         * The alarm can be defined such that it triggers repeatedly.  A
+         * definition of an alarm with a repeating trigger MUST include both
+         * the "DURATION" and "REPEAT" properties.  The "DURATION" property
+         * specifies the delay period, after which the alarm will repeat.
+         * Type: [String]
+         */
+        const val DURATION = "duration"
+
+        /**
+         * The "REPEAT" property specifies the number of additional
+         * repetitions that the alarm will be triggered.  This repetition
+         * count is in addition to the initial triggering of the alarm.  Both
+         * of these properties MUST be present in order to specify a
+         * repeating alarm.  If one of these two properties is absent, then
+         * the alarm will not repeat beyond the initial trigger.
+         * Type: [String]
+         */
+        const val REPEAT = "repeat"
+
+        /**
+         * Contains the uri of an attachment
+         * Type: [String]
+         */
+        const val ATTACH = "attach"
+
+        /**
+         * Purpose:  To specify other properties for the alarm.
+         * see [https://tools.ietf.org/html/rfc5545#section-3.8.4.3]
+         * Type: [String]
+         */
+        const val OTHER = "other"
+
+        /**
+         * Stores a timestamp with the absolute time when the alarm should be triggered.
+         * This value is stored as UNIX timestamp (milliseconds).
+         * Either a Alarm Trigger Time OR a Alarm Relative Duration must be provided, but not both!
+         * Type: [Long]
+         */
+        const val TRIGGER_TIME = "triggerTime"
+
+        /**
+         * Purpose:  This column/property specifies the timezone of the absolute trigger time.
+         * The corresponding datetime is stored in [TRIGGER_TIME].
+         * The value of a timezone can be:
+         * 1. the id of a Java timezone to represent the given timezone.
+         * 2. null to represent floating time.
+         * If an invalid value is passed, the Timezone is ignored and interpreted as UTC.
+         * See [https://tools.ietf.org/html/rfc5545#section-3.8.2.4]
+         * Type: [String]
+         */
+        const val TRIGGER_TIMEZONE = "triggerTimezone"
+
+        /**
+         * Purpose:  This property defines the field to which the duration is relatiive to.
+         * The possible values of a status are defined in the enum [AlarmRelativeTo].
+         * Use e.g. AlarmRelativeTo.START.name to put a correct String value in this field.
+         * AlarmRelativeTo.START would make the duration relative to DTSTART.
+         * AlarmRelativeTo.END would make the duration relative to DUE (only VTODO is supported!).
+         * If no valid AlarmRelativeTo is provided, the default value is AlarmRelativeTo.START.
+         * Type: [String]
+         */
+        const val TRIGGER_RELATIVE_TO = "triggerRelativeTo"
+
+        /**
+         * Purpose: Specifying a relative time for the
+         * trigger of the alarm.  The default duration is relative to the
+         * start of an event or to-do with which the alarm is associated.
+         * The duration can be explicitly set to trigger from either the end
+         * or the start of the associated event or to-do with the [TRIGGER_RELATIVE_TO]
+         * parameter.  A value of START will set the alarm to trigger off the
+         * start of the associated event or to-do.  A value of END will set
+         * the alarm to trigger off the end of the associated event or to-do.
+         * Either a positive or negative duration may be specified for the
+         * "TRIGGER" property.  An alarm with a positive duration is
+         * triggered after the associated start or end of the event or to-do.
+         * An alarm with a negative duration is triggered before the
+         * associated start or end of the event or to-do.
+         * Type: [String]
+         */
+        const val TRIGGER_RELATIVE_DURATION = "triggerRelativeDuration"
+
+        /** This enum class defines the possible values for the attribute [TRIGGER_RELATIVE_TO] for the Component VALARM  */
+        @Suppress("unused")
+        enum class AlarmRelativeTo {
+            START, END
+        }
+
+        /** This enum class defines the possible values for the attribute [ACTION] for the Component VALARM  */
+        @Suppress("unused")
+        enum class AlarmAction {
+            AUDIO, DISPLAY, EMAIL
+        }
+    }
+
+    @Suppress("unused")
+    object JtxUnknown {
+
+        /** The name of the the table for Unknown properties that are linked to an ICalObject.*/
+        private const val CONTENT_URI_PATH = "unknown"
+
+        /** The content uri of the resources table */
+        val CONTENT_URI: Uri by lazy { Uri.parse("content://$AUTHORITY/$CONTENT_URI_PATH") }
+
+
+        /** The name of the ID column for attachments.
+         * This is the unique identifier of an Attachment
+         * Type: [Long], references [JtxICalObject.ID]
+         */
+        const val ID = BaseColumns._ID
+
+        /** The name of the Foreign Key Column for IcalObjects.
+         * Type: [Long] */
+        const val ICALOBJECT_ID = "icalObjectId"
+
+
+        /***** The names of all the other columns  *****/
+        /**
+         * Purpose:  This property stores the unknown value as json
+         * Type: [String]
+         */
+        const val UNKNOWN_VALUE = "value"
+    }
+
+}
\ No newline at end of file
diff --git a/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt b/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
index 0d8e176..fd8bca0 100644
--- a/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
+++ b/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import at.bitfire.ical4android.util.AndroidTimeUtils
diff --git a/src/test/java/at/bitfire/ical4android/Css3ColorTest.kt b/src/test/java/at/bitfire/ical4android/Css3ColorTest.kt
index a4bd6c0..9828752 100644
--- a/src/test/java/at/bitfire/ical4android/Css3ColorTest.kt
+++ b/src/test/java/at/bitfire/ical4android/Css3ColorTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt b/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt
index 6f03906..395b8da 100644
--- a/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt
+++ b/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/test/java/at/bitfire/ical4android/EventTest.kt b/src/test/java/at/bitfire/ical4android/EventTest.kt
index a2ce504..e4d25c8 100644
--- a/src/test/java/at/bitfire/ical4android/EventTest.kt
+++ b/src/test/java/at/bitfire/ical4android/EventTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.model.Date
diff --git a/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt b/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
index ca7433e..894452e 100644
--- a/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
+++ b/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.data.CalendarBuilder
diff --git a/src/test/java/at/bitfire/ical4android/ICalendarTest.kt b/src/test/java/at/bitfire/ical4android/ICalendarTest.kt
index 329fd1b..7e1d0e7 100644
--- a/src/test/java/at/bitfire/ical4android/ICalendarTest.kt
+++ b/src/test/java/at/bitfire/ical4android/ICalendarTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/test/java/at/bitfire/ical4android/Ical4jTest.kt b/src/test/java/at/bitfire/ical4android/Ical4jTest.kt
index cec2c29..ad8d11b 100644
--- a/src/test/java/at/bitfire/ical4android/Ical4jTest.kt
+++ b/src/test/java/at/bitfire/ical4android/Ical4jTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.data.CalendarBuilder
diff --git a/src/test/java/at/bitfire/ical4android/MiscUtilsTest.kt b/src/test/java/at/bitfire/ical4android/MiscUtilsTest.kt
index 3ff78d9..e32ba0a 100644
--- a/src/test/java/at/bitfire/ical4android/MiscUtilsTest.kt
+++ b/src/test/java/at/bitfire/ical4android/MiscUtilsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import org.junit.Assert.assertTrue
diff --git a/src/test/java/at/bitfire/ical4android/TaskTest.kt b/src/test/java/at/bitfire/ical4android/TaskTest.kt
index 850b8e2..cbe0bcc 100644
--- a/src/test/java/at/bitfire/ical4android/TaskTest.kt
+++ b/src/test/java/at/bitfire/ical4android/TaskTest.kt
@@ -1,10 +1,6 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
 
 package at.bitfire.ical4android
 
diff --git a/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt b/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
index 3f632ca..44a02a0 100644
--- a/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
+++ b/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
@@ -1,3 +1,7 @@
+/***************************************************************************************************
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import at.bitfire.ical4android.util.TimeApiExtensions.requireTimeZone