Add accessibilityFocus and loseAccessibilityFocus as a11y actions (#14603)

bin/internal/engine.version

-8ac6f6efa177fb548dcdc81f1501f060b2ad1115
+a00f94582b61dec88a140751a8a43d79d525fd8f

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -3022,6 +3022,8 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
     MoveCursorHandler onMoveCursorForwardByCharacter,
     MoveCursorHandler onMoveCursorBackwardByCharacter,
     SetSelectionHandler onSetSelection,
+    VoidCallback onDidGainAccessibilityFocus,
+    VoidCallback onDidLoseAccessibilityFocus,
   }) : assert(container != null),
        _container = container,
        _explicitChildNodes = explicitChildNodes,
@@ -3050,6 +3052,8 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
        _onMoveCursorForwardByCharacter = onMoveCursorForwardByCharacter,
        _onMoveCursorBackwardByCharacter = onMoveCursorBackwardByCharacter,
        _onSetSelection = onSetSelection,
+       _onDidGainAccessibilityFocus = onDidGainAccessibilityFocus,
+       _onDidLoseAccessibilityFocus = onDidLoseAccessibilityFocus,
        super(child);
 
   /// If 'container' is true, this [RenderObject] will introduce a new
@@ -3493,6 +3497,62 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
       markNeedsSemanticsUpdate();
   }
 
+  /// The handler for [SemanticsAction.didGainAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler gains
+  /// the accessibility focus. The accessibility focus is the
+  /// green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidLoseAccessibilityFocus], which is invoked when the accessibility
+  ///    focus is removed from the node
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  VoidCallback get onDidGainAccessibilityFocus => _onDidGainAccessibilityFocus;
+  VoidCallback _onDidGainAccessibilityFocus;
+  set onDidGainAccessibilityFocus(VoidCallback handler) {
+    if (_onDidGainAccessibilityFocus == handler)
+      return;
+    final bool hadValue = _onDidGainAccessibilityFocus != null;
+    _onDidGainAccessibilityFocus = handler;
+    if ((handler != null) != hadValue)
+      markNeedsSemanticsUpdate();
+  }
+
+  /// The handler for [SemanticsAction.didLoseAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler
+  /// loses the accessibility focus. The accessibility focus is
+  /// the green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidGainAccessibilityFocus], which is invoked when the node gains
+  ///    accessibility focus
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  VoidCallback get onDidLoseAccessibilityFocus => _onDidLoseAccessibilityFocus;
+  VoidCallback _onDidLoseAccessibilityFocus;
+  set onDidLoseAccessibilityFocus(VoidCallback handler) {
+    if (_onDidLoseAccessibilityFocus == handler)
+      return;
+    final bool hadValue = _onDidLoseAccessibilityFocus != null;
+    _onDidLoseAccessibilityFocus = handler;
+    if ((handler != null) != hadValue)
+      markNeedsSemanticsUpdate();
+  }
+
   @override
   void describeSemanticsConfiguration(SemanticsConfiguration config) {
     super.describeSemanticsConfiguration(config);
@@ -3552,6 +3612,10 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
       config.onMoveCursorBackwardByCharacter = _performMoveCursorBackwardByCharacter;
     if (onSetSelection != null)
       config.onSetSelection = _performSetSelection;
+    if (onDidGainAccessibilityFocus != null)
+      config.onDidGainAccessibilityFocus = _performDidGainAccessibilityFocus;
+    if (onDidLoseAccessibilityFocus != null)
+      config.onDidLoseAccessibilityFocus = _performDidLoseAccessibilityFocus;
   }
 
   void _performTap() {
@@ -3623,6 +3687,16 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
     if (onSetSelection != null)
       onSetSelection(selection);
   }
+
+  void _performDidGainAccessibilityFocus() {
+    if (onDidGainAccessibilityFocus != null)
+      onDidGainAccessibilityFocus();
+  }
+
+  void _performDidLoseAccessibilityFocus() {
+    if (onDidLoseAccessibilityFocus != null)
+      onDidLoseAccessibilityFocus();
+  }
 }
 
 /// Causes the semantics of all earlier render objects below the same semantic

packages/flutter/lib/src/semantics/semantics.dart

@@ -329,6 +329,8 @@ class SemanticsProperties extends DiagnosticableTree {
     this.onMoveCursorForwardByCharacter,
     this.onMoveCursorBackwardByCharacter,
     this.onSetSelection,
+    this.onDidGainAccessibilityFocus,
+    this.onDidLoseAccessibilityFocus,
   });
 
   /// If non-null, indicates that this subtree represents something that can be
@@ -590,6 +592,44 @@ class SemanticsProperties extends DiagnosticableTree {
   /// beginning/end" or "Select all" from the local context menu.
   final SetSelectionHandler onSetSelection;
 
+  /// The handler for [SemanticsAction.didGainAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler gains
+  /// the accessibility focus. The accessibility focus is the
+  /// green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidLoseAccessibilityFocus], which is invoked when the accessibility
+  ///    focus is removed from the node
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  final VoidCallback onDidGainAccessibilityFocus;
+
+  /// The handler for [SemanticsAction.didLoseAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler
+  /// loses the accessibility focus. The accessibility focus is
+  /// the green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidGainAccessibilityFocus], which is invoked when the node gains
+  ///    accessibility focus
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  final VoidCallback onDidLoseAccessibilityFocus;
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder description) {
     super.debugFillProperties(description);
@@ -1977,6 +2017,54 @@ class SemanticsConfiguration {
     _onSetSelection = value;
   }
 
+  /// The handler for [SemanticsAction.didGainAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler gains
+  /// the accessibility focus. The accessibility focus is the
+  /// green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidLoseAccessibilityFocus], which is invoked when the accessibility
+  ///    focus is removed from the node
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  VoidCallback get onDidGainAccessibilityFocus => _onDidGainAccessibilityFocus;
+  VoidCallback _onDidGainAccessibilityFocus;
+  set onDidGainAccessibilityFocus(VoidCallback value) {
+    _addArgumentlessAction(SemanticsAction.didGainAccessibilityFocus, value);
+    _onDidGainAccessibilityFocus = value;
+  }
+
+  /// The handler for [SemanticsAction.didLoseAccessibilityFocus].
+  ///
+  /// This handler is invoked when the node annotated with this handler
+  /// loses the accessibility focus. The accessibility focus is
+  /// the green (on Android with TalkBack) or black (on iOS with VoiceOver)
+  /// rectangle shown on screen to indicate what element an accessibility
+  /// user is currently interacting with.
+  ///
+  /// The accessibility focus is different from the input focus. The input focus
+  /// is usually held by the element that currently responds to keyboard inputs.
+  /// Accessibility focus and input focus can be held by two different nodes!
+  ///
+  /// See also:
+  ///
+  ///  * [onDidGainAccessibilityFocus], which is invoked when the node gains
+  ///    accessibility focus
+  ///  * [FocusNode], [FocusScope], [FocusManager], which manage the input focus
+  VoidCallback get onDidLoseAccessibilityFocus => _onDidLoseAccessibilityFocus;
+  VoidCallback _onDidLoseAccessibilityFocus;
+  set onDidLoseAccessibilityFocus(VoidCallback value) {
+    _addArgumentlessAction(SemanticsAction.didLoseAccessibilityFocus, value);
+    _onDidLoseAccessibilityFocus = value;
+  }
+
   /// Returns the action handler registered for [action] or null if none was
   /// registered.
   ///

packages/flutter/lib/src/widgets/basic.dart

@@ -4869,6 +4869,8 @@ class Semantics extends SingleChildRenderObjectWidget {
     MoveCursorHandler onMoveCursorForwardByCharacter,
     MoveCursorHandler onMoveCursorBackwardByCharacter,
     SetSelectionHandler onSetSelection,
+    VoidCallback onDidGainAccessibilityFocus,
+    VoidCallback onDidLoseAccessibilityFocus,
   }) : this.fromProperties(
     key: key,
     child: child,
@@ -4899,6 +4901,8 @@ class Semantics extends SingleChildRenderObjectWidget {
       onPaste: onPaste,
       onMoveCursorForwardByCharacter: onMoveCursorForwardByCharacter,
       onMoveCursorBackwardByCharacter: onMoveCursorBackwardByCharacter,
+      onDidGainAccessibilityFocus: onDidGainAccessibilityFocus,
+      onDidLoseAccessibilityFocus: onDidLoseAccessibilityFocus,
     onSetSelection: onSetSelection,),
   );
 
@@ -4977,6 +4981,8 @@ class Semantics extends SingleChildRenderObjectWidget {
       onMoveCursorForwardByCharacter: properties.onMoveCursorForwardByCharacter,
       onMoveCursorBackwardByCharacter: properties.onMoveCursorBackwardByCharacter,
       onSetSelection: properties.onSetSelection,
+      onDidGainAccessibilityFocus: properties.onDidGainAccessibilityFocus,
+      onDidLoseAccessibilityFocus: properties.onDidLoseAccessibilityFocus,
     );
   }
 
@@ -5020,7 +5026,9 @@ class Semantics extends SingleChildRenderObjectWidget {
       ..onPaste = properties.onPaste
       ..onMoveCursorForwardByCharacter = properties.onMoveCursorForwardByCharacter
       ..onMoveCursorBackwardByCharacter = properties.onMoveCursorForwardByCharacter
-      ..onSetSelection = properties.onSetSelection;
+      ..onSetSelection = properties.onSetSelection
+      ..onDidGainAccessibilityFocus = properties.onDidGainAccessibilityFocus
+      ..onDidLoseAccessibilityFocus = properties.onDidLoseAccessibilityFocus;
   }
 
   @override

packages/flutter/test/widgets/semantics_test.dart

@@ -398,6 +398,8 @@ void main() {
         onMoveCursorForwardByCharacter: (bool _) => performedActions.add(SemanticsAction.moveCursorForwardByCharacter),
         onMoveCursorBackwardByCharacter: (bool _) => performedActions.add(SemanticsAction.moveCursorBackwardByCharacter),
         onSetSelection: (TextSelection _) => performedActions.add(SemanticsAction.setSelection),
+        onDidGainAccessibilityFocus: () => performedActions.add(SemanticsAction.didGainAccessibilityFocus),
+        onDidLoseAccessibilityFocus: () => performedActions.add(SemanticsAction.didLoseAccessibilityFocus),
       )
     );