Add word movement granularities to android (#5902)

lib/ui/semantics.dart

@@ -28,6 +28,8 @@ class SemanticsAction {
   static const int _kDidLoseAccessibilityFocusIndex = 1 << 16;
   static const int _kCustomAction = 1 << 17;
   static const int _kDismissIndex = 1 << 18;
+  static const int _kMoveCursorForwardByWordIndex = 1 << 19;
+  static const int _kMoveCursorBackwardByWordIndex = 1 << 20;
 
   /// The numerical value for this action.
   ///
@@ -163,6 +165,22 @@ class SemanticsAction {
   /// (with VoiceOver) users can perform a standard gesture to dismiss it.
   static const SemanticsAction dismiss = const SemanticsAction._(_kDismissIndex);
 
+  /// Move the cursor forward by one word.
+  ///
+  /// This is for example used by the cursor control in text fields.
+  ///
+  /// The action includes a boolean argument, which indicates whether the cursor
+  /// movement should extend (or start) a selection.
+  static const SemanticsAction moveCursorForwardByWord = const SemanticsAction._(_kMoveCursorForwardByWordIndex);
+
+  /// Move the cursor backward by one word.
+  ///
+  /// This is for example used by the cursor control in text fields.
+  ///
+  /// The action includes a boolean argument, which indicates whether the cursor
+  /// movement should extend (or start) a selection.
+  static const SemanticsAction moveCursorBackwardByWord = const SemanticsAction._(_kMoveCursorBackwardByWordIndex);
+
   /// The possible semantics actions.
   ///
   /// The map's key is the [index] of the action and the value is the action
@@ -187,6 +205,8 @@ class SemanticsAction {
     _kDidLoseAccessibilityFocusIndex: didLoseAccessibilityFocus,
     _kCustomAction: customAction,
     _kDismissIndex: dismiss,
+    _kMoveCursorForwardByWordIndex: moveCursorForwardByWord,
+    _kMoveCursorBackwardByWordIndex: moveCursorBackwardByWord,
   };
 
   @override
@@ -230,6 +250,10 @@ class SemanticsAction {
         return 'SemanticsAction.customAction';
       case _kDismissIndex:
         return 'SemanticsAction.dismiss';
+      case _kMoveCursorForwardByWordIndex:
+        return 'SemanticsAction.moveCursorForwardByWord';
+      case _kMoveCursorBackwardByWordIndex:
+        return 'SemanticsAction.moveCursorBackwardByWord';
     }
     return null;
   }

shell/platform/android/io/flutter/view/AccessibilityBridge.java

@@ -63,7 +63,9 @@ class AccessibilityBridge
         DID_GAIN_ACCESSIBILITY_FOCUS(1 << 15),
         DID_LOSE_ACCESSIBILITY_FOCUS(1 << 16),
         CUSTOM_ACTION(1 << 17),
-        DISMISS(1 << 18);
+        DISMISS(1 << 18),
+        MOVE_CURSOR_FORWARD_BY_WORD(1 << 19),
+        MOVE_CURSOR_BACKWARD_BY_WORD(1 << 20);
 
         Action(int value) {
             this.value = value;
@@ -172,6 +174,14 @@ class AccessibilityBridge
                 result.addAction(AccessibilityNodeInfo.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY);
                 granularities |= AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER;
             }
+            if (object.hasAction(Action.MOVE_CURSOR_FORWARD_BY_WORD)) {
+                result.addAction(AccessibilityNodeInfo.ACTION_NEXT_AT_MOVEMENT_GRANULARITY);
+                granularities |= AccessibilityNodeInfo.MOVEMENT_GRANULARITY_WORD;
+            }
+            if (object.hasAction(Action.MOVE_CURSOR_BACKWARD_BY_WORD)) {
+                result.addAction(AccessibilityNodeInfo.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY);
+                granularities |= AccessibilityNodeInfo.MOVEMENT_GRANULARITY_WORD;
+            }
             result.setMovementGranularities(granularities);
         }
         if (object.hasAction(Action.SET_SELECTION)) {
@@ -479,8 +489,20 @@ class AccessibilityBridge
                             Action.MOVE_CURSOR_BACKWARD_BY_CHARACTER, extendSelection);
                     return true;
                 }
+                break;
             }
-                // TODO(goderbauer): support other granularities.
+            case AccessibilityNodeInfo.MOVEMENT_GRANULARITY_WORD:
+                if (forward && object.hasAction(Action.MOVE_CURSOR_FORWARD_BY_WORD)) {
+                    mOwner.dispatchSemanticsAction(virtualViewId,
+                            Action.MOVE_CURSOR_FORWARD_BY_WORD, extendSelection);
+                    return true;
+                }
+                if (!forward && object.hasAction(Action.MOVE_CURSOR_BACKWARD_BY_WORD)) {
+                    mOwner.dispatchSemanticsAction(virtualViewId,
+                            Action.MOVE_CURSOR_BACKWARD_BY_WORD, extendSelection);
+                    return true;
+                }
+                break;
         }
         return false;
     }