MarkdownToolBar: First attempt at the toolbar

This can be enabled via 'Settings -> Experimental'. It's very rough
right now and a lot still needs to be done.

Related to #157

assets/langs/en.yaml

@@ -62,6 +62,7 @@ settings:
     subtitle: Try out features in Development
     backlinks: Show Backlinks in Markdown Preview
     fs: Show File System
+    markdownToolbar: Show Markdown Toolbar in Editor
   editors:
     title: Editor Settings
     subtitle: Configure how different editors work

lib/editors/markdown_editor.dart

@@ -129,6 +129,23 @@ class MarkdownEditorState extends State<MarkdownEditor>
 
     Widget body = editingMode ? editor : NoteViewer(note: note);
 
+    if (Settings.instance.experimentalMarkdownToolbar && editingMode) {
+      body = Container(
+        height: 600,
+        child: Column(
+          children: <Widget>[
+            Expanded(child: editor),
+            MarkdownToolBar(
+              onHeader1: () => _modifyCurrentLine('# '),
+              onItallics: () => _modifyCurrentWord('*'),
+              onBold: () => _modifyCurrentWord('**'),
+            ),
+          ],
+          mainAxisSize: MainAxisSize.min,
+        ),
+      );
+    }
+
     var extraButton = IconButton(
       icon: editingMode
           ? const Icon(Icons.remove_red_eye)
@@ -226,4 +243,126 @@ class MarkdownEditorState extends State<MarkdownEditor>
 
   @override
   bool get noteModified => _noteModified;
+
+  void _modifyCurrentLine(String char) {
+    var selection = _textController.value.selection;
+    var text = _textController.value.text;
+
+    print('Base offset: ${selection.baseOffset}');
+    print('Extent offset: ${selection.extentOffset}');
+    var cursorPos = selection.baseOffset;
+    if (cursorPos == -1) {
+      cursorPos = 0;
+    }
+    print('CursorPos: $cursorPos');
+
+    var lineStartPos =
+        text.lastIndexOf('\n', cursorPos == 0 ? 0 : cursorPos - 1);
+    if (lineStartPos == -1) {
+      lineStartPos = 0;
+    }
+
+    var lineEndPos = text.indexOf('\n', cursorPos);
+    if (lineEndPos == -1) {
+      lineEndPos = text.length;
+    }
+
+    print('Line Start: $lineStartPos');
+    print('Line End: $lineEndPos');
+    print('Line: ${text.substring(lineStartPos, lineEndPos)}');
+
+    // Check if already present
+    if (text.startsWith(char, lineStartPos)) {
+      print('Removing `$char`');
+      _textController.text = text.replaceFirst(char, '', lineStartPos);
+      _textController.selection =
+          TextSelection.collapsed(offset: cursorPos - char.length);
+      return;
+    }
+
+    print('Adding `$char`');
+    _textController.text = text.replaceRange(lineStartPos, lineStartPos, char);
+    _textController.selection =
+        TextSelection.collapsed(offset: cursorPos + char.length);
+  }
+
+  void _modifyCurrentWord(String char) {
+    var selection = _textController.value.selection;
+    var text = _textController.value.text;
+
+    print('Base offset: ${selection.baseOffset}');
+    print('Extent offset: ${selection.extentOffset}');
+    var cursorPos = selection.baseOffset;
+    if (cursorPos == -1) {
+      cursorPos = 0;
+    }
+    print('CursorPos: $cursorPos');
+
+    var wordStartPos =
+        text.lastIndexOf(' ', cursorPos == 0 ? 0 : cursorPos - 1);
+    if (wordStartPos == -1) {
+      wordStartPos = 0;
+    }
+
+    var wordEndPos = text.indexOf(' ', cursorPos);
+    if (wordEndPos == -1) {
+      wordEndPos = text.length;
+    }
+
+    print('Word Start: $wordStartPos');
+    print('Word End: $wordEndPos');
+    print('Word: ${text.substring(wordStartPos, wordEndPos)}');
+
+    // Check if already present
+    if (text.startsWith(char, wordStartPos)) {
+      print('Removing `$char`');
+      _textController.text = text.replaceFirst(char, '', wordStartPos);
+      _textController.selection =
+          TextSelection.collapsed(offset: cursorPos - (char.length * 2));
+      return;
+    }
+
+    print('Adding `$char`');
+    _textController.text = text.replaceRange(wordStartPos, wordStartPos, char);
+    wordEndPos += char.length;
+
+    _textController.text =
+        text.replaceRange(wordEndPos - 1, wordEndPos - 1, char);
+    _textController.selection =
+        TextSelection.collapsed(offset: cursorPos + (char.length * 2));
+
+    print('$char');
+  }
+}
+
+class MarkdownToolBar extends StatelessWidget {
+  final Function onHeader1;
+  final Function onItallics;
+  final Function onBold;
+
+  MarkdownToolBar({
+    @required this.onHeader1,
+    @required this.onItallics,
+    @required this.onBold,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      children: [
+        IconButton(
+          icon: const Text('H1'),
+          onPressed: onHeader1,
+        ),
+        IconButton(
+          icon: const Text('I'),
+          onPressed: onItallics,
+        ),
+        IconButton(
+          icon: const Text('B'),
+          onPressed: onBold,
+        ),
+      ],
+    );
+  }
 }

lib/screens/settings_experimental.dart

@@ -47,6 +47,15 @@ class _ExperimentalSettingsScreenState
                 setState(() {});
               },
             ),
+            SwitchListTile(
+              title: Text(tr('settings.experimental.markdownToolbar')),
+              value: settings.experimentalFs,
+              onChanged: (bool newVal) {
+                settings.experimentalFs = newVal;
+                settings.save();
+                setState(() {});
+              },
+            ),
           ],
           padding: const EdgeInsets.fromLTRB(0.0, 16.0, 0.0, 0.0),
         ),

lib/settings.dart

@@ -54,6 +54,7 @@ class Settings {
 
   bool experimentalBacklinks = true;
   bool experimentalFs = false;
+  bool experimentalMarkdownToolbar = false;
 
   bool zenMode = false;
   bool saveTitleInH1 = true;
@@ -123,6 +124,8 @@ class Settings {
     experimentalBacklinks =
         pref.getBool("experimentalBacklinks") ?? experimentalBacklinks;
     experimentalFs = pref.getBool("experimentalFs") ?? experimentalFs;
+    experimentalMarkdownToolbar = pref.getBool("experimentalMarkdownToolbar") ??
+        experimentalMarkdownToolbar;
 
     zenMode = pref.getBool("zenMode") ?? zenMode;
     saveTitleInH1 = pref.getBool("saveTitleInH1") ?? saveTitleInH1;
@@ -194,6 +197,8 @@ class Settings {
     _setBool(pref, "experimentalBacklinks", experimentalBacklinks,
         defaultSet.experimentalBacklinks);
     _setBool(pref, "experimentalFs", experimentalFs, defaultSet.experimentalFs);
+    _setBool(pref, "experimentalMarkdownToolbar", experimentalMarkdownToolbar,
+        defaultSet.experimentalMarkdownToolbar);
     _setBool(pref, "zenMode", zenMode, defaultSet.zenMode);
     _setBool(pref, "saveTitleInH1", saveTitleInH1, defaultSet.saveTitleInH1);
 
@@ -257,6 +262,7 @@ class Settings {
       'debugLogLevel': debugLogLevel,
       'experimentalBacklinks': experimentalBacklinks.toString(),
       'experimentalFs': experimentalFs.toString(),
+      'experimentalMarkdownToolbar': experimentalMarkdownToolbar.toString(),
       'zenMode': zenMode.toString(),
       'saveTitleInH1': saveTitleInH1.toString(),
     };