Enhance context based formatting

Signed-off-by: Stefan Niedermann <info@niedermann.it>

17 files changed, 525 insertions, 74 deletions

diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/util/CommentsUtil.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/util/CommentsUtil.java
index 5251291c8..8fa24988d 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/util/CommentsUtil.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/util/CommentsUtil.java
@@ -1,12 +1,14 @@
 package it.niedermann.nextcloud.deck.ui.card.comments.util;
 
 
+import androidx.annotation.Nullable;
 import androidx.core.util.Pair;
 
 public class CommentsUtil {
 
+    @Nullable
     public static Pair<String, Integer> getUserNameForMentionProposal(String text, int cursorPosition) {
-        Pair result = null;
+        Pair<String, Integer> result = null;
 
         if (text != null) {
             // find start of relevant substring
diff --git a/app/src/test/java/it/niedermann/nextcloud/deck/CommentsUtilTest.java b/app/src/test/java/it/niedermann/nextcloud/deck/CommentsUtilTest.java
index 47a23392e..bc76207e0 100644
--- a/app/src/test/java/it/niedermann/nextcloud/deck/CommentsUtilTest.java
+++ b/app/src/test/java/it/niedermann/nextcloud/deck/CommentsUtilTest.java
@@ -7,6 +7,7 @@ import it.niedermann.nextcloud.deck.ui.card.comments.util.CommentsUtil;
 
 public class CommentsUtilTest {
 
+    @SuppressWarnings("ConstantConditions")
     @Test
     public void testMentionDiscovery() {
         Assert.assertNull(CommentsUtil.getUserNameForMentionProposal("", 0));
diff --git a/markdown/build.gradle b/markdown/build.gradle
index c30c18a5a..d4ba32ef6 100644
--- a/markdown/build.gradle
+++ b/markdown/build.gradle
@@ -32,6 +32,7 @@ android {
 
 dependencies {
     implementation 'com.github.nextcloud:Android-SingleSignOn:0.5.4'
+    implementation 'com.github.stefan-niedermann:android-commons:0.1.1'
 
     implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation "androidx.lifecycle:lifecycle-livedata:2.2.0"
diff --git a/markdown/src/androidTest/java/it/niedermann/android/markdown/ExampleInstrumentedTest.java b/markdown/src/androidTest/java/it/niedermann/android/markdown/ExampleInstrumentedTest.java
deleted file mode 100644
index e765e0663..000000000
--- a/markdown/src/androidTest/java/it/niedermann/android/markdown/ExampleInstrumentedTest.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package it.niedermann.android.markdown;
-
-import android.content.Context;
-
-import androidx.test.ext.junit.runners.AndroidJUnit4;
-import androidx.test.platform.app.InstrumentationRegistry;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import static org.junit.Assert.assertEquals;
-
-/**
- * Instrumented test, which will execute on an Android device.
- *
- * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
- */
-@RunWith(AndroidJUnit4.class)
-public class ExampleInstrumentedTest {
-    @Test
-    public void useAppContext() {
-        // Context of the app under test.
-        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
-        assertEquals("it.niedermann.android.markdown.test", appContext.getPackageName());
-    }
-}
\ No newline at end of file
diff --git a/markdown/src/androidTest/java/it/niedermann/android/markdown/MarkwonMarkdownUtilTest.java b/markdown/src/androidTest/java/it/niedermann/android/markdown/MarkwonMarkdownUtilTest.java
new file mode 100644
index 000000000..b20f7fd36
--- /dev/null
+++ b/markdown/src/androidTest/java/it/niedermann/android/markdown/MarkwonMarkdownUtilTest.java
@@ -0,0 +1,112 @@
+package it.niedermann.android.markdown;
+
+import junit.framework.TestCase;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil;
+
+/**
+ * Tests the NoteUtil
+ * Created by stefan on 06.10.15.
+ */
+public class MarkwonMarkdownUtilTest extends TestCase {
+
+    public void testGetStartOfLine() {
+        //language=md
+        StringBuilder test = new StringBuilder(
+                "# Test-Note\n" + // line start 0
+                        "\n" + // line start 12
+                        "- [ ] this is a test note\n" + // line start 13
+                        "- [x] test\n" + // line start 39
+                        "[test](https://example.com)\n" + // line start 50
+                        "\n" + // line start 77
+                        "\n" // line start 78
+        );
+
+        for (int i = 0; i < test.length(); i++) {
+            int startOfLine = MarkwonMarkdownUtil.getStartOfLine(test, i);
+            if (i <= 11) {
+                assertEquals(0, startOfLine);
+            } else if (i <= 12) {
+                assertEquals(12, startOfLine);
+            } else if (i <= 38) {
+                assertEquals(13, startOfLine);
+            } else if (i <= 49) {
+                assertEquals(39, startOfLine);
+            } else if (i <= 77) {
+                assertEquals(50, startOfLine);
+            } else if (i <= 78) {
+                assertEquals(78, startOfLine);
+            } else if (i <= 79) {
+                assertEquals(79, startOfLine);
+            }
+        }
+    }
+
+    public void testGetEndOfLine() {
+        //language=md
+        StringBuilder test = new StringBuilder(
+                "# Test-Note\n" + // line 0 - 11
+                        "\n" + // line 12 - 12
+                        "- [ ] this is a test note\n" + // line 13 - 38
+                        "- [x] test\n" + // line start 39 - 49
+                        "[test](https://example.com)\n" + // line 50 - 77
+                        "\n" + // line 77 - 78
+                        "\n" // line 78 - 79
+        );
+
+        for (int i = 0; i < test.length(); i++) {
+            int endOfLine = MarkwonMarkdownUtil.getEndOfLine(test, i);
+            if (i <= 11) {
+                assertEquals(11, endOfLine);
+            } else if (i <= 12) {
+                assertEquals(12, endOfLine);
+            } else if (i <= 38) {
+                assertEquals(38, endOfLine);
+            } else if (i <= 49) {
+                assertEquals(49, endOfLine);
+            } else if (i <= 77) {
+                assertEquals(77, endOfLine);
+            } else if (i <= 78) {
+                assertEquals(78, endOfLine);
+            } else if (i <= 79) {
+                assertEquals(79, endOfLine);
+            }
+        }
+    }
+
+    public void testLineStartsWithCheckbox() {
+        Map<String, Boolean> lines = new HashMap<>();
+        lines.put("- [ ] ", true);
+        lines.put("- [x] ", true);
+        lines.put("* [ ] ", true);
+        lines.put("* [x] ", true);
+        lines.put("- [ ]", true);
+        lines.put("- [x]", true);
+        lines.put("* [ ]", true);
+        lines.put("* [x]", true);
+
+        lines.put("-[ ] ", false);
+        lines.put("-[x] ", false);
+        lines.put("*[ ] ", false);
+        lines.put("*[x] ", false);
+        lines.put("-[ ]", false);
+        lines.put("-[x]", false);
+        lines.put("*[ ]", false);
+        lines.put("*[x]", false);
+
+        lines.put("- [] ", false);
+        lines.put("* [] ", false);
+        lines.put("- []", false);
+        lines.put("* []", false);
+
+        lines.put("-[] ", false);
+        lines.put("*[] ", false);
+        lines.put("-[]", false);
+        lines.put("*[]", false);
+
+        lines.forEach((key, value) -> assertEquals(value, (Boolean) MarkwonMarkdownUtil.lineStartsWithCheckbox(key)));
+    }
+}
\ No newline at end of file
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownEditor.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownEditor.java
index 7dd73a94b..345a75347 100644
--- a/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownEditor.java
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownEditor.java
@@ -1,6 +1,7 @@
 package it.niedermann.android.markdown.markwon;
 
 import android.content.Context;
+import android.os.Build;
 import android.util.AttributeSet;
 import android.widget.EditText;
 
@@ -15,6 +16,8 @@ import io.noties.markwon.editor.MarkwonEditor;
 import io.noties.markwon.editor.handler.EmphasisEditHandler;
 import io.noties.markwon.editor.handler.StrongEmphasisEditHandler;
 import it.niedermann.android.markdown.MarkdownEditor;
+import it.niedermann.android.markdown.markwon.format.ContextBasedFormattingCallback;
+import it.niedermann.android.markdown.markwon.format.ContextBasedRangeFormattingCallback;
 import it.niedermann.android.markdown.markwon.handler.BlockQuoteEditHandler;
 import it.niedermann.android.markdown.markwon.handler.CodeBlockEditHandler;
 import it.niedermann.android.markdown.markwon.handler.CodeEditHandler;
@@ -47,6 +50,10 @@ public class MarkwonMarkdownEditor extends AppCompatEditText implements Markdown
                 .useEditHandler(new HeadingEditHandler())
                 .build();
         addTextChangedListener(new AutoContinuationTextWatcher(editor, this));
+        setCustomSelectionActionModeCallback(new ContextBasedRangeFormattingCallback(this));
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            setCustomInsertionActionModeCallback(new ContextBasedFormattingCallback(this));
+        }
     }
 
     @Override
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownUtil.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownUtil.java
index d33401b47..fdaf405da 100644
--- a/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownUtil.java
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/MarkwonMarkdownUtil.java
@@ -21,6 +21,7 @@ import io.noties.markwon.syntax.Prism4jThemeDefault;
 import io.noties.markwon.syntax.SyntaxHighlightPlugin;
 import io.noties.prism4j.Prism4j;
 import io.noties.prism4j.annotations.PrismBundle;
+import it.niedermann.android.markdown.markwon.model.EListType;
 import it.niedermann.android.markdown.markwon.plugins.NextcloudMentionsPlugin;
 import it.niedermann.android.markdown.markwon.plugins.ThemePlugin;
 
@@ -62,4 +63,48 @@ public class MarkwonMarkdownUtil {
         return initMarkwonViewer(context)
                 .usePlugin(NextcloudMentionsPlugin.create(context, mentions));
     }
+
+    public static int getStartOfLine(@NonNull CharSequence s, int cursorPosition) {
+        int startOfLine = cursorPosition;
+        while (startOfLine > 0 && s.charAt(startOfLine - 1) != '\n') {
+            startOfLine--;
+        }
+        return startOfLine;
+    }
+
+    public static int getEndOfLine(@NonNull CharSequence s, int cursorPosition) {
+        int nextLinebreak = s.toString().indexOf('\n', cursorPosition);
+        if (nextLinebreak > -1) {
+            return nextLinebreak;
+        }
+        return cursorPosition;
+    }
+
+    public static String getListItemIfIsEmpty(@NonNull String line) {
+        for (EListType listType : EListType.values()) {
+            if (line.equals(listType.checkboxUncheckedWithTrailingSpace)) {
+                return listType.checkboxUncheckedWithTrailingSpace;
+            } else if (line.equals(listType.listSymbolWithTrailingSpace)) {
+                return listType.listSymbolWithTrailingSpace;
+            }
+        }
+        return null;
+    }
+
+    public static boolean lineStartsWithCheckbox(@NonNull String line) {
+        for (EListType listType : EListType.values()) {
+            if (lineStartsWithCheckbox(line, listType)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public static boolean lineStartsWithCheckbox(@NonNull String line, @NonNull EListType listType) {
+        return line.startsWith(listType.checkboxUnchecked) || line.startsWith(listType.checkboxChecked);
+    }
+
+    public static boolean lineStartsWithList(@NonNull String line, @NonNull EListType listType) {
+        return line.startsWith(listType.listSymbol);
+    }
 }
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedFormattingCallback.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedFormattingCallback.java
new file mode 100644
index 000000000..6bed4b1db
--- /dev/null
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedFormattingCallback.java
@@ -0,0 +1,127 @@
+package it.niedermann.android.markdown.markwon.format;
+
+import android.text.SpannableStringBuilder;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.ActionMode;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import it.niedermann.android.markdown.R;
+import it.niedermann.android.markdown.markwon.MarkwonMarkdownEditor;
+import it.niedermann.android.markdown.markwon.model.EListType;
+import it.niedermann.android.util.ClipboardUtil;
+
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.getEndOfLine;
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.getStartOfLine;
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.lineStartsWithCheckbox;
+
+public class ContextBasedFormattingCallback implements ActionMode.Callback {
+
+    private static final String TAG = ContextBasedFormattingCallback.class.getSimpleName();
+
+    private final MarkwonMarkdownEditor editText;
+
+    public ContextBasedFormattingCallback(MarkwonMarkdownEditor editText) {
+        this.editText = editText;
+    }
+
+    @Override
+    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
+        mode.getMenuInflater().inflate(R.menu.context_based_formatting, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
+        final CharSequence text = editText.getText();
+        if (text != null) {
+            final int cursorPosition = editText.getSelectionStart();
+            if (cursorPosition >= 0 && cursorPosition <= text.length()) {
+                final int startOfLine = getStartOfLine(text, cursorPosition);
+                final int endOfLine = getEndOfLine(text, startOfLine);
+                final String line = text.subSequence(startOfLine, endOfLine).toString();
+                if (lineStartsWithCheckbox(line)) {
+                    menu.findItem(R.id.checkbox).setVisible(false);
+                    Log.i(TAG, "Hide checkbox menu item because line starts already with checkbox");
+                }
+            } else {
+                Log.e(TAG, "SelectionStart is " + cursorPosition + ". Expected to be between 0 and " + text.length());
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
+        int itemId = item.getItemId();
+        if (itemId == R.id.checkbox) {
+            insertCheckbox();
+            return true;
+        } else if (itemId == R.id.link) {
+            insertLink();
+            return true;
+        }
+        return false;
+    }
+
+    private void insertCheckbox() {
+        final CharSequence text = editText.getText();
+        if (text == null) {
+            editText.setMarkdownString(EListType.DASH.checkboxUncheckedWithTrailingSpace);
+            editText.setSelection(EListType.DASH.checkboxUncheckedWithTrailingSpace.length());
+        } else {
+            final int originalCursorPosition = editText.getSelectionStart();
+            final int startOfLine = getStartOfLine(text, originalCursorPosition);
+            Log.i(TAG, "Inserting checkbox at position " + startOfLine);
+            final CharSequence part1 = text.subSequence(0, startOfLine);
+            final CharSequence part2 = text.subSequence(startOfLine, text.length());
+            editText.setMarkdownString(TextUtils.concat(part1, EListType.DASH.checkboxUncheckedWithTrailingSpace, part2));
+            editText.setSelection(originalCursorPosition + EListType.DASH.checkboxUncheckedWithTrailingSpace.length());
+        }
+    }
+
+    private void insertLink() {
+        final CharSequence text = editText.getText();
+        final SpannableStringBuilder ssb = new SpannableStringBuilder(text);
+        final boolean textToFormatIsLink;
+        final int start;
+        int end;
+        if (text == null) {
+            start = end = 0;
+            textToFormatIsLink = false;
+        } else {
+            start = text.length();
+            end = start;
+            textToFormatIsLink = TextUtils.indexOf(text.subSequence(start, end), "http") == 0;
+        }
+
+        if (textToFormatIsLink) {
+            Log.i(TAG, "Inserting link description for position " + start + " to " + end);
+            ssb.insert(end, ")");
+            ssb.insert(start, "[](");
+        } else {
+            String clipboardURL = ClipboardUtil.INSTANCE.getClipboardURLorNull(editText.getContext());
+            if (clipboardURL != null) {
+                Log.i(TAG, "Inserting link from clipboard at position " + start + " to " + end + ": " + clipboardURL);
+                ssb.insert(end, "](" + clipboardURL + ")");
+                end += clipboardURL.length();
+            } else {
+                Log.i(TAG, "Inserting empty link for position " + start + " to " + end);
+                ssb.insert(end, "]()");
+            }
+            ssb.insert(start, "[");
+        }
+        editText.setMarkdownString(ssb);
+        if (textToFormatIsLink) {
+            editText.setSelection(start + 1);
+        } else {
+            editText.setSelection(end + 3); // after <end>](
+        }
+    }
+
+    @Override
+    public void onDestroyActionMode(ActionMode mode) {
+        // Nothing to do here...
+    }
+}
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedRangeFormattingCallback.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedRangeFormattingCallback.java
new file mode 100644
index 000000000..20b26674d
--- /dev/null
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/format/ContextBasedRangeFormattingCallback.java
@@ -0,0 +1,130 @@
+package it.niedermann.android.markdown.markwon.format;
+
+import android.graphics.Typeface;
+import android.text.SpannableStringBuilder;
+import android.text.TextUtils;
+import android.text.style.StyleSpan;
+import android.util.SparseIntArray;
+import android.view.ActionMode;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import androidx.annotation.Nullable;
+
+import it.niedermann.android.markdown.R;
+import it.niedermann.android.markdown.markwon.MarkwonMarkdownEditor;
+import it.niedermann.android.util.ClipboardUtil;
+
+public class ContextBasedRangeFormattingCallback implements ActionMode.Callback {
+
+    private static final String TAG = ContextBasedRangeFormattingCallback.class.getSimpleName();
+
+    private final MarkwonMarkdownEditor editText;
+
+    public ContextBasedRangeFormattingCallback(MarkwonMarkdownEditor editText) {
+        this.editText = editText;
+    }
+
+    @Override
+    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
+        mode.getMenuInflater().inflate(R.menu.context_based_range_formatting, menu);
+
+        final SparseIntArray styleFormatMap = new SparseIntArray();
+        styleFormatMap.append(R.id.bold, Typeface.BOLD);
+        styleFormatMap.append(R.id.italic, Typeface.ITALIC);
+
+        MenuItem item;
+        CharSequence title;
+        SpannableStringBuilder ssb;
+
+        for (int i = 0; i < styleFormatMap.size(); i++) {
+            item = menu.findItem(styleFormatMap.keyAt(i));
+            title = item.getTitle();
+            ssb = new SpannableStringBuilder(title);
+            ssb.setSpan(new StyleSpan(styleFormatMap.valueAt(i)), 0, title.length(), 0);
+            item.setTitle(ssb);
+        }
+
+        return true;
+    }
+
+    @Override
+    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
+        // TODO hide actions if not available?
+        return false;
+    }
+
+    @Override
+    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
+        final SpannableStringBuilder ssb = new SpannableStringBuilder(editText.getText());
+        final int itemId = item.getItemId();
+        final int start = editText.getSelectionStart();
+        int end = editText.getSelectionEnd();
+
+        if (itemId == R.id.bold) {
+            final String punctuation = "**";
+            final boolean hasAlreadyMarkdown = hasAlreadyMarkdown(editText.getText(), start, end, punctuation);
+            if (hasAlreadyMarkdown) {
+                removeMarkdown(ssb, start, end, punctuation);
+            } else {
+                ssb.insert(end, punctuation);
+                ssb.insert(start, punctuation);
+            }
+            editText.setMarkdownString(ssb);
+            editText.setSelection(hasAlreadyMarkdown ? end - punctuation.length() : end + punctuation.length() * 2);
+            return true;
+        } else if (itemId == R.id.italic) {
+            final String punctuation = "*";
+            final boolean hasAlreadyMarkdown = hasAlreadyMarkdown(editText.getText(), start, end, punctuation);
+            if (hasAlreadyMarkdown) {
+                removeMarkdown(ssb, start, end, punctuation);
+            } else {
+                ssb.insert(end, punctuation);
+                ssb.insert(start, punctuation);
+            }
+            editText.setMarkdownString(ssb);
+            editText.setSelection(hasAlreadyMarkdown ? end - punctuation.length() : end + punctuation.length() * 2);
+            return true;
+        } else if (itemId == R.id.link) {
+            final CharSequence text = editText.getText();
+            final boolean textToFormatIsLink = text != null && TextUtils.indexOf(text.subSequence(start, end), "http") == 0;
+            if (textToFormatIsLink) {
+                ssb.insert(end, ")");
+                ssb.insert(start, "[](");
+            } else {
+                String clipboardURL = ClipboardUtil.INSTANCE.getClipboardURLorNull(editText.getContext());
+                if (clipboardURL != null) {
+                    ssb.insert(end, "](" + clipboardURL + ")");
+                    end += clipboardURL.length();
+                } else {
+                    ssb.insert(end, "]()");
+                }
+                ssb.insert(start, "[");
+            }
+            editText.setMarkdownString(ssb);
+            if (textToFormatIsLink) {
+                editText.setSelection(start + 1);
+            } else {
+                editText.setSelection(end + 3); // after <end>](
+            }
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void onDestroyActionMode(ActionMode mode) {
+        // Nothing to do here...
+    }
+
+    private static boolean hasAlreadyMarkdown(@Nullable CharSequence text, int start, int end, String punctuation) {
+        return text != null && (start > punctuation.length() && punctuation.contentEquals(text.subSequence(start - punctuation.length(), start)) &&
+                text.length() > end + punctuation.length() && punctuation.contentEquals(text.subSequence(end, end + punctuation.length())));
+    }
+
+    private static void removeMarkdown(SpannableStringBuilder ssb, int start, int end, String punctuation) {
+        // FIXME disabled, because it does not work properly and might cause data loss
+        ssb.delete(start - punctuation.length(), start);
+        ssb.delete(end - punctuation.length(), end);
+    }
+}
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/model/EListType.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/model/EListType.java
new file mode 100644
index 000000000..a03987fda
--- /dev/null
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/model/EListType.java
@@ -0,0 +1,21 @@
+package it.niedermann.android.markdown.markwon.model;
+
+public enum EListType {
+    STAR('*'),
+    DASH('-'),
+    PLUS('+');
+
+    public final String listSymbol;
+    public final String listSymbolWithTrailingSpace;
+    public final String checkboxChecked;
+    public final String checkboxUnchecked;
+    public final String checkboxUncheckedWithTrailingSpace;
+
+    EListType(char listSymbol) {
+        this.listSymbol = String.valueOf(listSymbol);
+        this.listSymbolWithTrailingSpace = listSymbol + " ";
+        this.checkboxChecked = listSymbolWithTrailingSpace + "[x]";
+        this.checkboxUnchecked = listSymbolWithTrailingSpace + "[ ]";
+        this.checkboxUncheckedWithTrailingSpace = checkboxUnchecked + " ";
+    }
+}
\ No newline at end of file
diff --git a/markdown/src/main/java/it/niedermann/android/markdown/markwon/textwatcher/AutoContinuationTextWatcher.java b/markdown/src/main/java/it/niedermann/android/markdown/markwon/textwatcher/AutoContinuationTextWatcher.java
index 384dc78c5..795812f4c 100644
--- a/markdown/src/main/java/it/niedermann/android/markdown/markwon/textwatcher/AutoContinuationTextWatcher.java
+++ b/markdown/src/main/java/it/niedermann/android/markdown/markwon/textwatcher/AutoContinuationTextWatcher.java
@@ -10,6 +10,12 @@ import java.util.concurrent.Executors;
 import io.noties.markwon.editor.MarkwonEditor;
 import io.noties.markwon.editor.MarkwonEditorTextWatcher;
 import it.niedermann.android.markdown.markwon.MarkwonMarkdownEditor;
+import it.niedermann.android.markdown.markwon.model.EListType;
+
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.getListItemIfIsEmpty;
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.getStartOfLine;
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.lineStartsWithCheckbox;
+import static it.niedermann.android.markdown.markwon.MarkwonMarkdownUtil.lineStartsWithList;
 
 /**
  * Automatically continues lists and checkbox lists when pressing enter
@@ -88,51 +94,4 @@ public class AutoContinuationTextWatcher implements TextWatcher {
             }
         }
     }
-
-    private static int getStartOfLine(@NonNull CharSequence s, int cursorPosition) {
-        int startOfLine = cursorPosition;
-        while (startOfLine > 0 && s.charAt(startOfLine - 1) != '\n') {
-            startOfLine--;
-        }
-        return startOfLine;
-    }
-
-    private static String getListItemIfIsEmpty(@NonNull String line) {
-        for (EListType listType : EListType.values()) {
-            if (line.equals(listType.checkboxUncheckedWithTrailingSpace)) {
-                return listType.checkboxUncheckedWithTrailingSpace;
-            } else if (line.equals(listType.listSymbolWithTrailingSpace)) {
-                return listType.listSymbolWithTrailingSpace;
-            }
-        }
-        return null;
-    }
-
-    private static boolean lineStartsWithCheckbox(@NonNull String line, @NonNull EListType listType) {
-        return line.startsWith(listType.checkboxUnchecked) || line.startsWith(listType.checkboxChecked);
-    }
-
-    private static boolean lineStartsWithList(@NonNull String line, @NonNull EListType listType) {
-        return line.startsWith(listType.listSymbol);
-    }
-
-    enum EListType {
-        STAR('*'),
-        DASH('-'),
-        PLUS('+');
-
-        final String listSymbol;
-        final String listSymbolWithTrailingSpace;
-        final String checkboxChecked;
-        final String checkboxUnchecked;
-        final String checkboxUncheckedWithTrailingSpace;
-
-        EListType(char listSymbol) {
-            this.listSymbol = String.valueOf(listSymbol);
-            this.listSymbolWithTrailingSpace = listSymbol + " ";
-            this.checkboxChecked = listSymbolWithTrailingSpace + "[x]";
-            this.checkboxUnchecked = listSymbolWithTrailingSpace + "[ ]";
-            this.checkboxUncheckedWithTrailingSpace = checkboxUnchecked + " ";
-        }
-    }
 }
diff --git a/markdown/src/main/res/drawable/ic_format_bold_black_24dp.xml b/markdown/src/main/res/drawable/ic_format_bold_black_24dp.xml
new file mode 100644
index 000000000..0b06db879
--- /dev/null
+++ b/markdown/src/main/res/drawable/ic_format_bold_black_24dp.xml
@@ -0,0 +1,11 @@
+<vector android:autoMirrored="true"
+    android:height="24dp"
+    android:tint="#757575"
+    android:viewportHeight="24.0"
+    android:viewportWidth="24.0"
+    android:width="24dp"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M15.6,10.79c0.97,-0.67 1.65,-1.77 1.65,-2.79 0,-2.26 -1.75,-4 -4,-4L7,4v14h7.04c2.09,0 3.71,-1.7 3.71,-3.79 0,-1.52 -0.86,-2.82 -2.15,-3.42zM10,6.5h3c0.83,0 1.5,0.67 1.5,1.5s-0.67,1.5 -1.5,1.5h-3v-3zM13.5,15.5L10,15.5v-3h3.5c0.83,0 1.5,0.67 1.5,1.5s-0.67,1.5 -1.5,1.5z" />
+</vector>
diff --git a/markdown/src/main/res/drawable/ic_format_italic_black_24dp.xml b/markdown/src/main/res/drawable/ic_format_italic_black_24dp.xml
new file mode 100644
index 000000000..20680318b
--- /dev/null
+++ b/markdown/src/main/res/drawable/ic_format_italic_black_24dp.xml
@@ -0,0 +1,11 @@
+<vector android:autoMirrored="true"
+    android:height="24dp"
+    android:tint="#757575"
+    android:viewportHeight="24.0"
+    android:viewportWidth="24.0"
+    android:width="24dp"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M10,4v3h2.21l-3.42,8H6v3h8v-3h-2.21l3.42,-8H18V4z" />
+</vector>
diff --git a/markdown/src/main/res/drawable/ic_insert_link_black_24dp.xml b/markdown/src/main/res/drawable/ic_insert_link_black_24dp.xml
new file mode 100644
index 000000000..91b42f7fb
--- /dev/null
+++ b/markdown/src/main/res/drawable/ic_insert_link_black_24dp.xml
@@ -0,0 +1,11 @@
+<vector android:autoMirrored="true"
+    android:height="24dp"
+    android:tint="#757575"
+    android:viewportHeight="24.0"
+    android:viewportWidth="24.0"
+    android:width="24dp"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M3.9,12c0,-1.71 1.39,-3.1 3.1,-3.1h4L11,7L7,7c-2.76,0 -5,2.24 -5,5s2.24,5 5,5h4v-1.9L7,15.1c-1.71,0 -3.1,-1.39 -3.1,-3.1zM8,13h8v-2L8,11v2zM17,7h-4v1.9h4c1.71,0 3.1,1.39 3.1,3.1s-1.39,3.1 -3.1,3.1h-4L13,17h4c2.76,0 5,-2.24 5,-5s-2.24,-5 -5,-5z" />
+</vector>
diff --git a/markdown/src/main/res/menu/context_based_formatting.xml b/markdown/src/main/res/menu/context_based_formatting.xml
new file mode 100644
index 000000000..9bf2d779f
--- /dev/null
+++ b/markdown/src/main/res/menu/context_based_formatting.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/checkbox"
+        android:title="@string/simple_checkbox"
+        app:showAsAction="ifRoom" />
+    <item
+        android:id="@+id/link"
+        android:icon="@drawable/ic_insert_link_black_24dp"
+        android:title="@string/simple_link"
+        app:showAsAction="ifRoom" />
+</menu>
\ No newline at end of file
diff --git a/markdown/src/main/res/menu/context_based_range_formatting.xml b/markdown/src/main/res/menu/context_based_range_formatting.xml
new file mode 100644
index 000000000..68d701f83
--- /dev/null
+++ b/markdown/src/main/res/menu/context_based_range_formatting.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/italic"
+        android:icon="@drawable/ic_format_italic_black_24dp"
+        android:title="@string/simple_italic"
+        app:showAsAction="ifRoom" />
+    <item
+        android:id="@+id/bold"
+        android:icon="@drawable/ic_format_bold_black_24dp"
+        android:title="@string/simple_bold"
+        app:showAsAction="ifRoom" />
+    <item
+        android:id="@+id/link"
+        android:icon="@drawable/ic_insert_link_black_24dp"
+        android:title="@string/simple_link"
+        app:showAsAction="ifRoom" />
+</menu>
\ No newline at end of file
diff --git a/markdown/src/main/res/values/strings.xml b/markdown/src/main/res/values/strings.xml
new file mode 100644
index 000000000..f78123e3b
--- /dev/null
+++ b/markdown/src/main/res/values/strings.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="simple_checkbox">Checkbox</string>
+    <string name="simple_bold">Bold</string>
+    <string name="simple_link">Link</string>
+    <string name="simple_italic">Italic</string>
+</resources>
\ No newline at end of file