Refactor some models to use proper constructors instead of custom initialize() methods

10 files changed, 147 insertions, 189 deletions

diff --git a/app/src/main/java/at/bitfire/davdroid/db/CollectionDao.kt b/app/src/main/java/at/bitfire/davdroid/db/CollectionDao.kt
index a6446a35..6e72ede3 100644
--- a/app/src/main/java/at/bitfire/davdroid/db/CollectionDao.kt
+++ b/app/src/main/java/at/bitfire/davdroid/db/CollectionDao.kt
@@ -15,11 +15,14 @@ import androidx.room.Query
 interface CollectionDao: SyncableDao<Collection> {
 
     @Query("SELECT DISTINCT color FROM collection WHERE serviceId=:id")
-    fun colorsByService(id: Long): LiveData<List<Int>>
+    fun colorsByServiceLive(id: Long): LiveData<List<Int>>
 
     @Query("SELECT * FROM collection WHERE id=:id")
     fun get(id: Long): Collection?
 
+    @Query("SELECT * FROM collection WHERE id=:id")
+    fun getLive(id: Long): LiveData<Collection>
+
     @Query("SELECT * FROM collection WHERE serviceId=:serviceId")
     fun getByService(serviceId: Long): List<Collection>
 
diff --git a/app/src/main/java/at/bitfire/davdroid/db/HomeSetDao.kt b/app/src/main/java/at/bitfire/davdroid/db/HomeSetDao.kt
index aebc7146..9d8c2aa2 100644
--- a/app/src/main/java/at/bitfire/davdroid/db/HomeSetDao.kt
+++ b/app/src/main/java/at/bitfire/davdroid/db/HomeSetDao.kt
@@ -20,7 +20,7 @@ interface HomeSetDao: SyncableDao<HomeSet> {
     fun getBindableByService(serviceId: Long): List<HomeSet>
 
     @Query("SELECT COUNT(*) FROM homeset WHERE serviceId=:serviceId AND privBind")
-    fun hasBindableByService(serviceId: Long): LiveData<Boolean>
+    fun hasBindableByServiceLive(serviceId: Long): LiveData<Boolean>
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     fun insertOrReplace(homeSet: HomeSet): Long
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionInfoFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionInfoFragment.kt
index 96016f2d..4f780a67 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionInfoFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionInfoFragment.kt
@@ -4,22 +4,16 @@
 
 package at.bitfire.davdroid.ui.account
 
-import android.app.Application
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.annotation.UiThread
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.viewModels
-import androidx.lifecycle.AndroidViewModel
-import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
 import at.bitfire.davdroid.databinding.CollectionPropertiesBinding
 import at.bitfire.davdroid.db.AppDatabase
-import at.bitfire.davdroid.db.Collection
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 
@@ -39,13 +33,15 @@ class CollectionInfoFragment: DialogFragment() {
 
     }
 
-    val model by viewModels<Model>()
-
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-        arguments?.getLong(ARGS_COLLECTION_ID)?.let { id ->
-            model.initialize(id)
+    val model by viewModels<Model>() {
+        object : ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>) =
+                Model(requireArguments().getLong(ARGS_COLLECTION_ID)) as T
         }
+    }
 
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         val view = CollectionPropertiesBinding.inflate(inflater, container, false)
         view.lifecycleOwner = this
         view.model = model
@@ -55,25 +51,11 @@ class CollectionInfoFragment: DialogFragment() {
 
 
     class Model(
-            application: Application
-    ): AndroidViewModel(application), KoinComponent {
+        collectionId: Long
+    ): ViewModel(), KoinComponent {
 
         val db by inject<AppDatabase>()
-        var collection = MutableLiveData<Collection>()
-
-        private var initialized = false
-
-        @UiThread
-        fun initialize(collectionId: Long) {
-            // TODO use constructor and model factory instead of custom initialize()
-            if (initialized)
-                return
-            initialized = true
-
-            viewModelScope.launch(Dispatchers.IO) {
-                collection.postValue(db.collectionDao().get(collectionId))
-            }
-        }
+        var collection = db.collectionDao().getLive(collectionId)
 
     }
 
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionsFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionsFragment.kt
index 7c4787d7..29b7dc00 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionsFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/CollectionsFragment.kt
@@ -55,7 +55,12 @@ abstract class CollectionsFragment: Fragment(), KoinComponent, SwipeRefreshLayou
         object: ViewModelProvider.Factory {
             @Suppress("UNCHECKED_CAST")
             override fun <T: ViewModel> create(modelClass: Class<T>): T =
-                    Model(requireActivity().application, accountModel) as T
+                Model(
+                    requireActivity().application,
+                    accountModel,
+                    requireArguments().getLong(EXTRA_SERVICE_ID),
+                    requireArguments().getString(EXTRA_COLLECTION_TYPE) ?: throw IllegalArgumentException("EXTRA_COLLECTION_TYPE required")
+                ) as T
         }
     }
 
@@ -79,12 +84,6 @@ abstract class CollectionsFragment: Fragment(), KoinComponent, SwipeRefreshLayou
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        // don't get the activity ViewModel in onCreate(), it may crash
-        model.initialize(
-                arguments?.getLong(EXTRA_SERVICE_ID) ?: throw IllegalArgumentException("EXTRA_SERVICE_ID required"),
-                arguments?.getString(EXTRA_COLLECTION_TYPE) ?: throw IllegalArgumentException("EXTRA_COLLECTION_TYPE required")
-        )
-
         model.isRefreshing.observe(viewLifecycleOwner, Observer { nowRefreshing ->
             binding.swipeRefresh.isRefreshing = nowRefreshing
         })
@@ -263,37 +262,28 @@ abstract class CollectionsFragment: Fragment(), KoinComponent, SwipeRefreshLayou
 
 
     class Model(
-            val context: Application,
-            val accountModel: AccountActivity.Model
+        val context: Application,
+        val accountModel: AccountActivity.Model,
+        val serviceId: Long,
+        val collectionType: String
     ): ViewModel(), DavService.RefreshingStatusListener, KoinComponent, SyncStatusObserver {
 
         private val db by inject<AppDatabase>()
 
-        val serviceId = MutableLiveData<Long>()
-        private lateinit var collectionType: String
-
         // cache task provider
         val taskProvider by lazy { TaskUtils.currentProvider(context) }
 
-        val hasWriteableCollections: LiveData<Boolean> =
-            Transformations.switchMap(serviceId) { service ->
-                db.homeSetDao().hasBindableByService(service)
-            }
-        val collectionsColors: LiveData<List<Int>> =
-            Transformations.switchMap(serviceId) { service ->
-                db.collectionDao().colorsByService(service)
-            }
+        val hasWriteableCollections = db.homeSetDao().hasBindableByServiceLive(serviceId)
+        val collectionsColors = db.collectionDao().colorsByServiceLive(serviceId)
         val collectionsPager: LiveData<Pager<Int, Collection>> =
-            Transformations.switchMap(accountModel.showOnlyPersonal) { onlyPersonal ->
-                Transformations.map(serviceId) { service ->
-                    Pager(PagingConfig(pageSize = 25)) {
-                        if (onlyPersonal)
-                            // show only personal collections
-                            db.collectionDao().pagePersonalByServiceAndType(service, collectionType)
-                        else
-                            // show all collections
-                            db.collectionDao().pageByServiceAndType(service, collectionType)
-                    }
+            Transformations.map(accountModel.showOnlyPersonal) { onlyPersonal ->
+                Pager(PagingConfig(pageSize = 25)) {
+                    if (onlyPersonal)
+                        // show only personal collections
+                        db.collectionDao().pagePersonalByServiceAndType(serviceId, collectionType)
+                    else
+                        // show all collections
+                        db.collectionDao().pageByServiceAndType(serviceId, collectionType)
                 }
             }
 
@@ -319,11 +309,7 @@ abstract class CollectionsFragment: Fragment(), KoinComponent, SwipeRefreshLayou
         val isSyncPending = MutableLiveData<Boolean>()
 
 
-        fun initialize(id: Long, collectionType: String) {
-            this.collectionType = collectionType
-            if (serviceId.value == null)
-                serviceId.value = id
-
+        init {
             if (context.bindService(Intent(context, DavService::class.java), svcConn, Context.BIND_AUTO_CREATE))
                 davServiceConn = svcConn
 
@@ -344,14 +330,12 @@ abstract class CollectionsFragment: Fragment(), KoinComponent, SwipeRefreshLayou
         }
 
         fun refresh() {
-            serviceId.value?.let { svcId ->
-                DavService.refreshCollections(context, svcId)
-            }
+            DavService.refreshCollections(context, serviceId)
         }
 
         @AnyThread
         override fun onDavRefreshStatusChanged(id: Long, refreshing: Boolean) {
-            if (id == serviceId.value)
+            if (id == serviceId)
                 isRefreshing.postValue(refreshing)
         }
 
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateAddressBookActivity.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateAddressBookActivity.kt
index a3fdb297..2271ec4a 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateAddressBookActivity.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateAddressBookActivity.kt
@@ -5,19 +5,18 @@
 package at.bitfire.davdroid.ui.account
 
 import android.accounts.Account
-import android.app.Application
 import android.content.Intent
 import android.os.Bundle
 import android.text.Editable
 import android.view.Menu
 import android.view.MenuItem
 import androidx.activity.viewModels
-import androidx.annotation.MainThread
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.app.TaskStackBuilder
 import androidx.databinding.DataBindingUtil
-import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import at.bitfire.davdroid.R
 import at.bitfire.davdroid.databinding.ActivityCreateAddressBookBinding
@@ -39,8 +38,15 @@ class CreateAddressBookActivity: AppCompatActivity() {
         const val EXTRA_ACCOUNT = "account"
     }
 
-    private val account by lazy { intent.getParcelableExtra<Account>(EXTRA_ACCOUNT) ?: throw IllegalArgumentException("EXTRA_ACCOUNT must be set") }
-    val model by viewModels<Model>()
+    val model by viewModels<Model>() {
+        object: ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>): T {
+                val account = intent.getParcelableExtra<Account>(EXTRA_ACCOUNT) ?: throw IllegalArgumentException("EXTRA_ACCOUNT must be set")
+                return Model(account) as T
+            }
+        }
+    }
 
     lateinit var binding: ActivityCreateAddressBookBinding
 
@@ -67,9 +73,6 @@ class CreateAddressBookActivity: AppCompatActivity() {
         binding.homeset.setOnItemClickListener { parent, view, position, id ->
             model.homeSet = parent.getItemAtPosition(position) as HomeSet?
         }
-
-        if (savedInstanceState == null)
-            model.initialize(account)
     }
 
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
@@ -80,7 +83,7 @@ class CreateAddressBookActivity: AppCompatActivity() {
     override fun supportShouldUpRecreateTask(targetIntent: Intent) = true
 
     override fun onPrepareSupportNavigateUpTaskStack(builder: TaskStackBuilder) {
-        builder.editIntentAt(builder.intentCount - 1)?.putExtra(AccountActivity.EXTRA_ACCOUNT, account)
+        builder.editIntentAt(builder.intentCount - 1)?.putExtra(AccountActivity.EXTRA_ACCOUNT, model.account)
     }
 
 
@@ -123,10 +126,9 @@ class CreateAddressBookActivity: AppCompatActivity() {
 
 
     class Model(
-            application: Application
-    ) : AndroidViewModel(application), KoinComponent {
+        val account: Account
+    ) : ViewModel(), KoinComponent {
 
-        var account: Account? = null
         val db by inject<AppDatabase>()
 
         val displayName = MutableLiveData<String>()
@@ -137,17 +139,7 @@ class CreateAddressBookActivity: AppCompatActivity() {
         val homeSets = MutableLiveData<List<HomeSet>>()
         var homeSet: HomeSet? = null
 
-        fun clearNameError(s: Editable) {
-            displayNameError.value = null
-        }
-
-        @MainThread
-        fun initialize(account: Account) {
-            // TODO use constructor and model factory instead of custom initialize()
-            if (this.account != null)
-                return
-            this.account = account
-
+        init {
             viewModelScope.launch(Dispatchers.IO) {
                 // load account info
                 db.serviceDao().getByAccountAndType(account.name, Service.TYPE_CARDDAV)?.let { service ->
@@ -156,6 +148,10 @@ class CreateAddressBookActivity: AppCompatActivity() {
             }
         }
 
+        fun clearNameError(s: Editable) {
+            displayNameError.value = null
+        }
+
     }
 
 }
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCalendarActivity.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCalendarActivity.kt
index a64c2e96..902b6e48 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCalendarActivity.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCalendarActivity.kt
@@ -5,7 +5,6 @@
 package at.bitfire.davdroid.ui.account
 
 import android.accounts.Account
-import android.app.Application
 import android.content.Context
 import android.content.Intent
 import android.graphics.drawable.ColorDrawable
@@ -14,12 +13,12 @@ import android.view.*
 import android.widget.ArrayAdapter
 import android.widget.TextView
 import androidx.activity.viewModels
-import androidx.annotation.MainThread
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.app.NavUtils
 import androidx.databinding.DataBindingUtil
-import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import at.bitfire.davdroid.Constants
 import at.bitfire.davdroid.R
@@ -48,8 +47,15 @@ class CreateCalendarActivity: AppCompatActivity(), ColorPickerDialogListener {
         const val EXTRA_ACCOUNT = "account"
     }
 
-    private val account by lazy { intent.getParcelableExtra<Account>(EXTRA_ACCOUNT) ?: throw IllegalArgumentException("EXTRA_ACCOUNT must be set") }
-    val model by viewModels<Model>()
+    val model by viewModels<Model>() {
+        object: ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>): T {
+                val account = intent.getParcelableExtra<Account>(EXTRA_ACCOUNT) ?: throw IllegalArgumentException("EXTRA_ACCOUNT must be set")
+                return Model(account) as T
+            }
+        }
+    }
 
     lateinit var binding: ActivityCreateCalendarBinding
 
@@ -80,15 +86,12 @@ class CreateCalendarActivity: AppCompatActivity(), ColorPickerDialogListener {
             }
         }
         binding.homeset.setAdapter(homeSetAdapter)
-        binding.homeset.setOnItemClickListener { parent, view, position, id ->
+        binding.homeset.setOnItemClickListener { parent, _, position, _ ->
             model.homeSet = parent.getItemAtPosition(position) as HomeSet?
         }
 
         binding.timezone.setAdapter(TimeZoneAdapter(this))
         binding.timezone.setText(TimeZone.getDefault().id, false)
-
-        if (savedInstanceState == null)
-            model.initialize(account)
     }
 
     override fun onColorSelected(dialogId: Int, rgb: Int) {
@@ -211,10 +214,9 @@ class CreateCalendarActivity: AppCompatActivity(), ColorPickerDialogListener {
 
 
     class Model(
-            application: Application
-    ): AndroidViewModel(application), KoinComponent {
+        val account: Account
+    ): ViewModel(), KoinComponent {
 
-        var account: Account? = null
         val db by inject<AppDatabase>()
 
         val displayName = MutableLiveData<String>()
@@ -233,12 +235,7 @@ class CreateCalendarActivity: AppCompatActivity(), ColorPickerDialogListener {
         val supportVTODO = MutableLiveData<Boolean>()
         val supportVJOURNAL = MutableLiveData<Boolean>()
 
-        @MainThread
-        fun initialize(account: Account) {
-            if (this.account != null)
-                return
-            this.account = account
-
+        init {
             color.value = Constants.DAVDROID_GREEN_RGBA
 
             supportVEVENT.value = true
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCollectionFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCollectionFragment.kt
index cca37bd1..bc47d740 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCollectionFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/CreateCollectionFragment.kt
@@ -53,30 +53,37 @@ class CreateCollectionFragment: DialogFragment() {
         const val ARG_SUPPORTS_VJOURNAL = "supportsVJOURNAL"
     }
 
-    val model by viewModels<Model>()
+    val model by viewModels<Model>() {
+        object : ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>): T {
+                val args = requireArguments()
+
+                val account: Account = args.getParcelable(ARG_ACCOUNT) ?: throw IllegalArgumentException("ARG_ACCOUNT required")
+                val serviceType = args.getString(ARG_SERVICE_TYPE) ?: throw java.lang.IllegalArgumentException("ARG_SERVICE_TYPE required")
+                val collection = Collection(
+                    type = args.getString(ARG_TYPE) ?: throw IllegalArgumentException("ARG_TYPE required"),
+                    url = (args.getString(ARG_URL) ?: throw IllegalArgumentException("ARG_URL required")).toHttpUrl(),
+                    displayName = args.getString(ARG_DISPLAY_NAME),
+                    description = args.getString(ARG_DESCRIPTION),
+
+                    color = args.ifDefined(ARG_COLOR) { it.getInt(ARG_COLOR) },
+                    timezone = args.getString(ARG_TIMEZONE),
+                    supportsVEVENT = args.ifDefined(ARG_SUPPORTS_VEVENT) { it.getBoolean(ARG_SUPPORTS_VEVENT) },
+                    supportsVTODO = args.ifDefined(ARG_SUPPORTS_VTODO) { it.getBoolean(ARG_SUPPORTS_VTODO) },
+                    supportsVJOURNAL = args.ifDefined(ARG_SUPPORTS_VJOURNAL) { it.getBoolean(ARG_SUPPORTS_VJOURNAL) },
+
+                    sync = true     /* by default, sync collections which just have been created */
+                )
+
+                return Model(requireActivity().application, account, serviceType, collection) as T
+            }
+        }
+    }
 
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        val args = arguments ?: throw IllegalArgumentException()
-
-        model.account = args.getParcelable(ARG_ACCOUNT) ?: throw IllegalArgumentException("ARG_ACCOUNT required")
-        model.serviceType = args.getString(ARG_SERVICE_TYPE) ?: throw java.lang.IllegalArgumentException("ARG_SERVICE_TYPE required")
-
-        model.collection = Collection(
-                type = args.getString(ARG_TYPE) ?: throw IllegalArgumentException("ARG_TYPE required"),
-                url = (args.getString(ARG_URL) ?: throw IllegalArgumentException("ARG_URL required")).toHttpUrl(),
-                displayName = args.getString(ARG_DISPLAY_NAME),
-                description = args.getString(ARG_DESCRIPTION),
-
-                color = args.ifDefined(ARG_COLOR) { it.getInt(ARG_COLOR) },
-                timezone = args.getString(ARG_TIMEZONE),
-                supportsVEVENT = args.ifDefined(ARG_SUPPORTS_VEVENT) { it.getBoolean(ARG_SUPPORTS_VEVENT) },
-                supportsVTODO = args.ifDefined(ARG_SUPPORTS_VTODO) { it.getBoolean(ARG_SUPPORTS_VTODO) },
-                supportsVJOURNAL = args.ifDefined(ARG_SUPPORTS_VJOURNAL) { it.getBoolean(ARG_SUPPORTS_VJOURNAL) },
-
-                sync = true     /* by default, sync collections which just have been created */
-        )
 
         model.createCollection().observe(this, Observer { exception ->
             if (exception == null)
@@ -104,13 +111,12 @@ class CreateCollectionFragment: DialogFragment() {
 
 
     class Model(
-            app: Application
+        app: Application,
+        val account: Account,
+        val serviceType: String,
+        val collection: Collection
     ): AndroidViewModel(app), KoinComponent {
 
-        lateinit var account: Account
-        lateinit var serviceType: String
-        lateinit var collection: Collection
-
         val result = MutableLiveData<Exception>()
 
         fun createCollection(): LiveData<Exception> {
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/DeleteCollectionFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/DeleteCollectionFragment.kt
index 081d0a8c..9490b1b8 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/DeleteCollectionFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/DeleteCollectionFragment.kt
@@ -10,7 +10,6 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.annotation.MainThread
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.viewModels
 import androidx.lifecycle.*
@@ -43,17 +42,19 @@ class DeleteCollectionFragment: DialogFragment() {
         }
     }
 
-    val model by viewModels<Model>()
-
-
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        model.initialize(
-                requireArguments().getParcelable(ARG_ACCOUNT)!!,
-                requireArguments().getLong(ARG_COLLECTION_ID)
-        )
+    val model by viewModels<Model>() {
+        object : ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>): T =
+                Model(
+                    requireActivity().application,
+                    requireArguments().getParcelable(ARG_ACCOUNT) ?: throw IllegalArgumentException("ARG_ACCOUNT required"),
+                    requireArguments().getLong(ARG_COLLECTION_ID)
+                ) as T
+        }
     }
 
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         val binding = DeleteCollectionBinding.inflate(layoutInflater, null, false)
         binding.lifecycleOwner = this
@@ -82,31 +83,25 @@ class DeleteCollectionFragment: DialogFragment() {
 
 
     class Model(
-            application: Application
+        application: Application,
+        var account: Account,
+        val collectionId: Long
     ): AndroidViewModel(application), KoinComponent {
 
-        var account: Account? = null
-        var collectionInfo: Collection? = null
-
         val db by inject<AppDatabase>()
+        var collectionInfo: Collection? = null
 
         val confirmation = MutableLiveData<Boolean>()
         val result = MutableLiveData<Exception>()
 
-        @MainThread
-        fun initialize(account: Account, collectionId: Long) {
-            if (this.account == null)
-                this.account = account
-
-            if (collectionInfo == null)
-                viewModelScope.launch(Dispatchers.IO) {
-                    collectionInfo = db.collectionDao().get(collectionId)
-                }
+        init {
+            viewModelScope.launch(Dispatchers.IO) {
+                collectionInfo = db.collectionDao().get(collectionId)
+            }
         }
 
         fun deleteCollection(): LiveData<Exception> {
             viewModelScope.launch(Dispatchers.IO + NonCancellable) {
-                val account = account ?: return@launch
                 val collectionInfo = collectionInfo ?: return@launch
 
                 val context = getApplication<Application>()
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/RenameAccountFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/RenameAccountFragment.kt
index 4ca95d85..147ac43c 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/RenameAccountFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/RenameAccountFragment.kt
@@ -25,6 +25,7 @@ import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.viewModels
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.Observer
 import androidx.lifecycle.viewModelScope
 import at.bitfire.davdroid.DavUtils
 import at.bitfire.davdroid.InvalidAccountException
@@ -76,7 +77,7 @@ class RenameAccountFragment: DialogFragment() {
         layout.setPadding(8*density, 8*density, 8*density, 8*density)
         layout.addView(editText)
 
-        model.finished.observe(this, {
+        model.finished.observe(this, Observer {
             this@RenameAccountFragment.requireActivity().finish()
         })
 
@@ -163,14 +164,15 @@ class RenameAccountFragment: DialogFragment() {
             if (ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_CONTACTS) == PackageManager.PERMISSION_GRANTED)
                 try {
                     context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)?.let { provider ->
-                        for (addrBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book)))
-                            try {
+                        try {
+                            for (addrBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))) {
                                 val addressBook = LocalAddressBook(context, addrBookAccount, provider)
                                 if (oldAccount == addressBook.mainAccount)
                                     addressBook.mainAccount = Account(newName, oldAccount.type)
-                            } finally {
-                                provider.closeCompat()
                             }
+                        } finally {
+                            provider.closeCompat()
+                        }
                     }
                 } catch (e: Exception) {
                     Logger.log.log(Level.SEVERE, "Couldn't update address book accounts", e)
diff --git a/app/src/main/java/at/bitfire/davdroid/ui/account/WebcalFragment.kt b/app/src/main/java/at/bitfire/davdroid/ui/account/WebcalFragment.kt
index 7ba2b223..1b70e3f9 100644
--- a/app/src/main/java/at/bitfire/davdroid/ui/account/WebcalFragment.kt
+++ b/app/src/main/java/at/bitfire/davdroid/ui/account/WebcalFragment.kt
@@ -19,9 +19,7 @@ import android.view.*
 import androidx.annotation.WorkerThread
 import androidx.core.content.ContextCompat
 import androidx.fragment.app.viewModels
-import androidx.lifecycle.AndroidViewModel
-import androidx.lifecycle.MediatorLiveData
-import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.*
 import androidx.room.Transaction
 import at.bitfire.dav4jvm.UrlUtils
 import at.bitfire.davdroid.Constants
@@ -48,16 +46,23 @@ class WebcalFragment: CollectionsFragment() {
 
     override val noCollectionsStringId = R.string.account_no_webcals
 
-    val webcalModel by viewModels<WebcalModel>()
+    val webcalModel by viewModels<WebcalModel>() {
+        object : ViewModelProvider.Factory {
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : ViewModel> create(modelClass: Class<T>) =
+                WebcalModel(
+                    requireActivity().application,
+                    requireArguments().getLong(EXTRA_SERVICE_ID)
+                ) as T
+        }
+    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        webcalModel.subscribedUrls.observe(this, { urls ->
+        webcalModel.subscribedUrls.observe(this, Observer { urls ->
             Logger.log.log(Level.FINE, "Got Android calendar list", urls.keys)
         })
-
-        webcalModel.initialize(arguments?.getLong(EXTRA_SERVICE_ID) ?: throw IllegalArgumentException("EXTRA_SERVICE_ID required"))
     }
 
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) =
@@ -156,10 +161,10 @@ class WebcalFragment: CollectionsFragment() {
     }
 
 
-    class WebcalModel(application: Application): AndroidViewModel(application), KoinComponent {
-
-        private var initialized = false
-        private var serviceId: Long = 0
+    class WebcalModel(
+        application: Application,
+        val serviceId: Long
+    ): AndroidViewModel(application), KoinComponent {
 
         private val db by inject<AppDatabase>()
         private val resolver = application.contentResolver
@@ -167,10 +172,6 @@ class WebcalFragment: CollectionsFragment() {
         private var calendarPermission = false
         private val calendarProvider = object: MediatorLiveData<ContentProviderClient>() {
             init {
-                init()
-            }
-
-            fun init() {
                 calendarPermission = ContextCompat.checkSelfPermission(getApplication(), Manifest.permission.READ_CALENDAR) == PackageManager.PERMISSION_GRANTED
                 if (calendarPermission)
                     connect()
@@ -273,14 +274,6 @@ class WebcalFragment: CollectionsFragment() {
         }
 
 
-        fun initialize(dbServiceId: Long) {
-            if (initialized)
-                return
-            initialized = true
-
-            serviceId = dbServiceId
-        }
-
         fun unsubscribe(webcal: Collection) {
             viewModelScope.launch(Dispatchers.IO) {
                 // find first matching source (Webcal) URL