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lib/src/widgets/delegate.dart

@@ -18,29 +18,94 @@ abstract class EditorTextSelectionGestureDetectorBuilderDelegate {
   bool getSelectionEnabled();
 }
 
+/// Builds a [EditorTextSelectionGestureDetector] to wrap an [EditableText].
+///
+/// The class implements sensible defaults for many user interactions
+/// with an [EditableText] (see the documentation of the various gesture handler
+/// methods, e.g. [onTapDown], [onForcePressStart], etc.). Subclasses of
+/// [EditorTextSelectionGestureDetectorBuilder] can change the behavior
+/// performed in responds to these gesture events by overriding
+/// the corresponding handler methods of this class.
+///
+/// The resulting [EditorTextSelectionGestureDetector] to wrap an [EditableText]
+/// is obtained by calling [buildGestureDetector].
+///
+/// See also:
+///
+///  * [TextField], which uses a subclass to implement the Material-specific
+///    gesture logic of an [EditableText].
+///  * [CupertinoTextField], which uses a subclass to implement the
+///    Cupertino-specific gesture logic of an [EditableText].
 class EditorTextSelectionGestureDetectorBuilder {
-  EditorTextSelectionGestureDetectorBuilder(this.delegate);
+  /// Creates a [EditorTextSelectionGestureDetectorBuilder].
+  ///
+  /// The [delegate] must not be null.
+  EditorTextSelectionGestureDetectorBuilder({required this.delegate});
 
+  /// The delegate for this [EditorTextSelectionGestureDetectorBuilder].
+  ///
+  /// The delegate provides the builder with information about what actions can
+  /// currently be performed on the textfield. Based on this, the builder adds
+  /// the correct gesture handlers to the gesture detector.
+  @protected
   final EditorTextSelectionGestureDetectorBuilderDelegate delegate;
+
+  /// Whether to show the selection toolbar.
+  ///
+  /// It is based on the signal source when a [onTapDown] is called. This getter
+  /// will return true if current [onTapDown] event is triggered by a touch or
+  /// a stylus.
   bool shouldShowSelectionToolbar = true;
 
+  /// The [State] of the [EditableText] for which the builder will provide a
+  /// [EditorTextSelectionGestureDetector].
+  @protected
   EditorState? getEditor() {
     return delegate.getEditableTextKey().currentState;
   }
 
+  /// The [RenderObject] of the [EditableText] for which the builder will
+  /// provide a [EditorTextSelectionGestureDetector].
+  @protected
   RenderEditor? getRenderEditor() {
     return getEditor()!.getRenderEditor();
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onTapDown].
+  ///
+  /// By default, it forwards the tap to [RenderEditable.handleTapDown] and sets
+  /// [shouldShowSelectionToolbar] to true if the tap was initiated by a finger
+  /// or stylus.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onTapDown],
+  ///  which triggers this callback.
+  @protected
   void onTapDown(TapDownDetails details) {
     getRenderEditor()!.handleTapDown(details);
-
+    // The selection overlay should only be shown when the user is interacting
+    // through a touch screen (via either a finger or a stylus).
+    // A mouse shouldn't trigger the selection overlay.
+    // For backwards-compatibility, we treat a null kind the same as touch.
     final kind = details.kind;
     shouldShowSelectionToolbar = kind == null ||
         kind == PointerDeviceKind.touch ||
         kind == PointerDeviceKind.stylus;
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onForcePressStart].
+  ///
+  /// By default, it selects the word at the position of the force press,
+  /// if selection is enabled.
+  ///
+  /// This callback is only applicable when force press is enabled.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onForcePressStart],
+  ///  which triggers this callback.
+  @protected
   void onForcePressStart(ForcePressDetails details) {
     assert(delegate.getForcePressEnabled());
     shouldShowSelectionToolbar = true;
@@ -53,6 +118,18 @@ class EditorTextSelectionGestureDetectorBuilder {
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onForcePressEnd].
+  ///
+  /// By default, it selects words in the range specified in [details] and shows
+  /// toolbar if it is necessary.
+  ///
+  /// This callback is only applicable when force press is enabled.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onForcePressEnd],
+  ///  which triggers this callback.
+  @protected
   void onForcePressEnd(ForcePressDetails details) {
     assert(delegate.getForcePressEnabled());
     getRenderEditor()!.selectWordsInRange(
@@ -65,14 +142,44 @@ class EditorTextSelectionGestureDetectorBuilder {
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onSingleTapUp].
+  ///
+  /// By default, it selects word edge if selection is enabled.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onSingleTapUp], which triggers
+  ///    this callback.
+  @protected
   void onSingleTapUp(TapUpDetails details) {
     if (delegate.getSelectionEnabled()) {
       getRenderEditor()!.selectWordEdge(SelectionChangedCause.tap);
     }
   }
 
-  void onSingleTapCancel() {}
+  /// Handler for [EditorTextSelectionGestureDetector.onSingleTapCancel].
+  ///
+  /// By default, it services as place holder to enable subclass override.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onSingleTapCancel], which triggers
+  ///    this callback.
+  @protected
+  void onSingleTapCancel() {
+    /* Subclass should override this method if needed. */
+  }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onSingleLongTapStart].
+  ///
+  /// By default, it selects text position specified in [details] if selection
+  /// is enabled.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onSingleLongTapStart],
+  ///  which triggers this callback.
+  @protected
   void onSingleLongTapStart(LongPressStartDetails details) {
     if (delegate.getSelectionEnabled()) {
       getRenderEditor()!.selectPositionAt(
@@ -82,6 +189,16 @@ class EditorTextSelectionGestureDetectorBuilder {
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onSingleLongTapMoveUpdate]
+  ///
+  /// By default, it updates the selection location specified in [details] if
+  /// selection is enabled.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onSingleLongTapMoveUpdate], which
+  ///    triggers this callback.
+  @protected
   void onSingleLongTapMoveUpdate(LongPressMoveUpdateDetails details) {
     if (delegate.getSelectionEnabled()) {
       getRenderEditor()!.selectPositionAt(
@@ -91,12 +208,31 @@ class EditorTextSelectionGestureDetectorBuilder {
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onSingleLongTapEnd].
+  ///
+  /// By default, it shows toolbar if necessary.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onSingleLongTapEnd],
+  ///  which triggers this callback.
+  @protected
   void onSingleLongTapEnd(LongPressEndDetails details) {
     if (shouldShowSelectionToolbar) {
       getEditor()!.showToolbar();
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onDoubleTapDown].
+  ///
+  /// By default, it selects a word through [RenderEditable.selectWord] if
+  /// selectionEnabled and shows toolbar if necessary.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onDoubleTapDown],
+  ///  which triggers this callback.
+  @protected
   void onDoubleTapDown(TapDownDetails details) {
     if (delegate.getSelectionEnabled()) {
       getRenderEditor()!.selectWord(SelectionChangedCause.tap);
@@ -106,20 +242,52 @@ class EditorTextSelectionGestureDetectorBuilder {
     }
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onDragSelectionStart].
+  ///
+  /// By default, it selects a text position specified in [details].
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onDragSelectionStart],
+  ///  which triggers this callback.
+  @protected
   void onDragSelectionStart(DragStartDetails details) {
     getRenderEditor()!.handleDragStart(details);
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onDragSelectionUpdate].
+  ///
+  /// By default, it updates the selection location specified in the provided
+  /// details objects.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onDragSelectionUpdate],
+  ///  which triggers this callback./lib/src/material/text_field.dart
+  @protected
   void onDragSelectionUpdate(
       DragStartDetails startDetails, DragUpdateDetails updateDetails) {
     getRenderEditor()!.extendSelection(updateDetails.globalPosition,
         cause: SelectionChangedCause.drag);
   }
 
+  /// Handler for [EditorTextSelectionGestureDetector.onDragSelectionEnd].
+  ///
+  /// By default, it services as place holder to enable subclass override.
+  ///
+  /// See also:
+  ///
+  ///  * [EditorTextSelectionGestureDetector.onDragSelectionEnd],
+  ///  which triggers this callback.
+  @protected
   void onDragSelectionEnd(DragEndDetails details) {
     getRenderEditor()!.handleDragEnd(details);
   }
 
+  /// Returns a [EditorTextSelectionGestureDetector] configured with
+  /// the handlers provided by this builder.
+  ///
+  /// The [child] or its subtree should contain [EditableText].
   Widget build(HitTestBehavior behavior, Widget child) {
     return EditorTextSelectionGestureDetector(
       onTapDown: onTapDown,

lib/src/widgets/editor.dart

@@ -463,7 +463,8 @@ class _QuillEditorState extends State<QuillEditor>
 
 class _QuillEditorSelectionGestureDetectorBuilder
     extends EditorTextSelectionGestureDetectorBuilder {
-  _QuillEditorSelectionGestureDetectorBuilder(this._state) : super(_state);
+  _QuillEditorSelectionGestureDetectorBuilder(this._state)
+      : super(delegate: _state);
 
   final _QuillEditorState _state;