[Multiline Select] HomePage allows to select paragraph line on triple click (#983)

Co-authored-by: Luis Felipe Murguia Ramos <felipelfmr1@gmail.com>

example/lib/pages/home_page.dart

@@ -17,6 +17,12 @@ import 'package:tuple/tuple.dart';
 import '../universal_ui/universal_ui.dart';
 import 'read_only_page.dart';
 
+enum _SelectionType {
+  none,
+  word,
+  // line,
+}
+
 class HomePage extends StatefulWidget {
   @override
   _HomePageState createState() => _HomePageState();
@@ -25,6 +31,14 @@ class HomePage extends StatefulWidget {
 class _HomePageState extends State<HomePage> {
   QuillController? _controller;
   final FocusNode _focusNode = FocusNode();
+  Timer? _selectAllTimer;
+  _SelectionType _selectionType = _SelectionType.none;
+
+  @override
+  void dispose() {
+    _selectAllTimer?.cancel();
+    super.dispose();
+  }
 
   @override
   void initState() {
@@ -99,39 +113,109 @@ class _HomePageState extends State<HomePage> {
     );
   }
 
+  bool _onTripleClickSelection() {
+    final controller = _controller!;
+
+    _selectAllTimer?.cancel();
+    _selectAllTimer = null;
+
+    // If you want to select all text after paragraph, uncomment this line
+    // if (_selectionType == _SelectionType.line) {
+    //   final selection = TextSelection(
+    //     baseOffset: 0,
+    //     extentOffset: controller.document.length,
+    //   );
+
+    //   controller.updateSelection(selection, ChangeSource.REMOTE);
+
+    //   _selectionType = _SelectionType.none;
+
+    //   return true;
+    // }
+
+    if (controller.selection.isCollapsed) {
+      _selectionType = _SelectionType.none;
+    }
+
+    if (_selectionType == _SelectionType.none) {
+      _selectionType = _SelectionType.word;
+      _startTripleClickTimer();
+      return false;
+    }
+
+    if (_selectionType == _SelectionType.word) {
+      final child = controller.document.queryChild(
+        controller.selection.baseOffset,
+      );
+      final offset = child.node?.documentOffset ?? 0;
+      final length = child.node?.length ?? 0;
+
+      final selection = TextSelection(
+        baseOffset: offset,
+        extentOffset: offset + length,
+      );
+
+      controller.updateSelection(selection, ChangeSource.REMOTE);
+
+      // _selectionType = _SelectionType.line;
+
+      _selectionType = _SelectionType.none;
+
+      _startTripleClickTimer();
+
+      return true;
+    }
+
+    return false;
+  }
+
+  void _startTripleClickTimer() {
+    _selectAllTimer = Timer(const Duration(milliseconds: 900), () {
+      _selectionType = _SelectionType.none;
+    });
+  }
+
   Widget _buildWelcomeEditor(BuildContext context) {
-    var quillEditor = QuillEditor(
-      controller: _controller!,
-      scrollController: ScrollController(),
-      scrollable: true,
-      focusNode: _focusNode,
-      autoFocus: false,
-      readOnly: false,
-      placeholder: 'Add content',
-      enableSelectionToolbar: isMobile(),
-      expands: false,
-      padding: EdgeInsets.zero,
-      onImagePaste: _onImagePaste,
-      customStyles: DefaultStyles(
-        h1: DefaultTextBlockStyle(
-            const TextStyle(
-              fontSize: 32,
-              color: Colors.black,
-              height: 1.15,
-              fontWeight: FontWeight.w300,
-            ),
-            const Tuple2(16, 0),
-            const Tuple2(0, 0),
-            null),
-        sizeSmall: const TextStyle(fontSize: 9),
+    Widget quillEditor = MouseRegion(
+      cursor: SystemMouseCursors.text,
+      child: QuillEditor(
+        controller: _controller!,
+        scrollController: ScrollController(),
+        scrollable: true,
+        focusNode: _focusNode,
+        autoFocus: false,
+        readOnly: false,
+        placeholder: 'Add content',
+        enableSelectionToolbar: isMobile(),
+        expands: false,
+        padding: EdgeInsets.zero,
+        onImagePaste: _onImagePaste,
+        onTapUp: (details, p1) {
+          return _onTripleClickSelection();
+        },
+        customStyles: DefaultStyles(
+          h1: DefaultTextBlockStyle(
+              const TextStyle(
+                fontSize: 32,
+                color: Colors.black,
+                height: 1.15,
+                fontWeight: FontWeight.w300,
+              ),
+              const Tuple2(16, 0),
+              const Tuple2(0, 0),
+              null),
+          sizeSmall: const TextStyle(fontSize: 9),
+        ),
+        embedBuilders: [
+          ...FlutterQuillEmbeds.builders(),
+          NotesEmbedBuilder(addEditNote: _addEditNote)
+        ],
       ),
-      embedBuilders: [
-        ...FlutterQuillEmbeds.builders(),
-        NotesEmbedBuilder(addEditNote: _addEditNote)
-      ],
     );
     if (kIsWeb) {
-      quillEditor = QuillEditor(
+      quillEditor = MouseRegion(
+        cursor: SystemMouseCursors.text,
+        child: QuillEditor(
           controller: _controller!,
           scrollController: ScrollController(),
           scrollable: true,
@@ -141,6 +225,9 @@ class _HomePageState extends State<HomePage> {
           placeholder: 'Add content',
           expands: false,
           padding: EdgeInsets.zero,
+          onTapUp: (details, p1) {
+            return _onTripleClickSelection();
+          },
           customStyles: DefaultStyles(
             h1: DefaultTextBlockStyle(
                 const TextStyle(
@@ -154,7 +241,9 @@ class _HomePageState extends State<HomePage> {
                 null),
             sizeSmall: const TextStyle(fontSize: 9),
           ),
-          embedBuilders: defaultEmbedBuildersWeb);
+          embedBuilders: defaultEmbedBuildersWeb,
+        ),
+      );
     }
     var toolbar = QuillToolbar.basic(
       controller: _controller!,