Android accessibility bridge also fire selection change event when it…

… predict selection change. (flutter#30199)
nt4f04uNd · Dec 10, 2021 · 1ed10bb · 1ed10bb
1 parent 806d8bc
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diff --git a/shell/platform/android/io/flutter/view/AccessibilityBridge.java b/shell/platform/android/io/flutter/view/AccessibilityBridge.java
@@ -1208,7 +1208,23 @@ private boolean performCursorMoveAction(
         arguments.getBoolean(AccessibilityNodeInfo.ACTION_ARGUMENT_EXTEND_SELECTION_BOOLEAN);
     // The voice access expects the semantics node to update immediately. We update the semantics
     // node based on prediction. If the result is incorrect, it will be updated in the next frame.
+    final int previousTextSelectionBase = semanticsNode.textSelectionBase;
+    final int previousTextSelectionExtent = semanticsNode.textSelectionExtent;
     predictCursorMovement(semanticsNode, granularity, forward, extendSelection);
+
+    if (previousTextSelectionBase != semanticsNode.textSelectionBase
+        || previousTextSelectionExtent != semanticsNode.textSelectionExtent) {
+      final String value = semanticsNode.value != null ? semanticsNode.value : "";
+      final AccessibilityEvent selectionEvent =
+          obtainAccessibilityEvent(
+              semanticsNode.id, AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
+      selectionEvent.getText().add(value);
+      selectionEvent.setFromIndex(semanticsNode.textSelectionBase);
+      selectionEvent.setToIndex(semanticsNode.textSelectionExtent);
+      selectionEvent.setItemCount(value.length());
+      sendAccessibilityEvent(selectionEvent);
+    }
+
     switch (granularity) {
       case AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER:
         {

diff --git a/shell/platform/android/test/io/flutter/view/AccessibilityBridgeTest.java b/shell/platform/android/test/io/flutter/view/AccessibilityBridgeTest.java
@@ -6,6 +6,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.eq;
@@ -1106,6 +1107,107 @@ public void itCanPredictCursorMovementsWithGranularityWord() {
     assertEquals(nodeInfo.getTextSelectionEnd(), 5);
   }
 
+  @Test
+  public void itAlsoFireSelectionEventWhenPredictCursorMovements() {
+    AccessibilityChannel mockChannel = mock(AccessibilityChannel.class);
+    AccessibilityViewEmbedder mockViewEmbedder = mock(AccessibilityViewEmbedder.class);
+    AccessibilityManager mockManager = mock(AccessibilityManager.class);
+    View mockRootView = mock(View.class);
+    Context context = mock(Context.class);
+    when(mockRootView.getContext()).thenReturn(context);
+    when(context.getPackageName()).thenReturn("test");
+    AccessibilityBridge accessibilityBridge =
+        setUpBridge(
+            /*rootAccessibilityView=*/ mockRootView,
+            /*accessibilityChannel=*/ mockChannel,
+            /*accessibilityManager=*/ mockManager,
+            /*contentResolver=*/ null,
+            /*accessibilityViewEmbedder=*/ mockViewEmbedder,
+            /*platformViewsAccessibilityDelegate=*/ null);
+
+    ViewParent mockParent = mock(ViewParent.class);
+    when(mockRootView.getParent()).thenReturn(mockParent);
+    when(mockManager.isEnabled()).thenReturn(true);
+
+    TestSemanticsNode root = new TestSemanticsNode();
+    root.id = 0;
+    TestSemanticsNode node1 = new TestSemanticsNode();
+    node1.id = 1;
+    node1.value = "some text";
+    node1.textSelectionBase = 0;
+    node1.textSelectionExtent = 0;
+    node1.addFlag(AccessibilityBridge.Flag.IS_TEXT_FIELD);
+    root.children.add(node1);
+    TestSemanticsUpdate testSemanticsUpdate = root.toUpdate();
+    testSemanticsUpdate.sendUpdateToBridge(accessibilityBridge);
+    Bundle bundle = new Bundle();
+    bundle.putInt(
+        AccessibilityNodeInfo.ACTION_ARGUMENT_MOVEMENT_GRANULARITY_INT,
+        AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER);
+    bundle.putBoolean(AccessibilityNodeInfo.ACTION_ARGUMENT_EXTEND_SELECTION_BOOLEAN, false);
+    accessibilityBridge.performAction(
+        1, AccessibilityNodeInfo.ACTION_NEXT_AT_MOVEMENT_GRANULARITY, bundle);
+    ArgumentCaptor<AccessibilityEvent> eventCaptor =
+        ArgumentCaptor.forClass(AccessibilityEvent.class);
+    verify(mockParent, times(2))
+        .requestSendAccessibilityEvent(eq(mockRootView), eventCaptor.capture());
+    AccessibilityEvent event = eventCaptor.getAllValues().get(1);
+    assertEquals(event.getEventType(), AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
+    assertEquals(event.getText().toString(), "[" + node1.value + "]");
+    assertEquals(event.getFromIndex(), 1);
+    assertEquals(event.getToIndex(), 1);
+    assertEquals(event.getItemCount(), node1.value.length());
+  }
+
+  @Test
+  public void itDoesNotFireSelectionEventWhenPredictCursorMovementsDoesNotChangeSelection() {
+    AccessibilityChannel mockChannel = mock(AccessibilityChannel.class);
+    AccessibilityViewEmbedder mockViewEmbedder = mock(AccessibilityViewEmbedder.class);
+    AccessibilityManager mockManager = mock(AccessibilityManager.class);
+    View mockRootView = mock(View.class);
+    Context context = mock(Context.class);
+    when(mockRootView.getContext()).thenReturn(context);
+    when(context.getPackageName()).thenReturn("test");
+    AccessibilityBridge accessibilityBridge =
+        setUpBridge(
+            /*rootAccessibilityView=*/ mockRootView,
+            /*accessibilityChannel=*/ mockChannel,
+            /*accessibilityManager=*/ mockManager,
+            /*contentResolver=*/ null,
+            /*accessibilityViewEmbedder=*/ mockViewEmbedder,
+            /*platformViewsAccessibilityDelegate=*/ null);
+
+    ViewParent mockParent = mock(ViewParent.class);
+    when(mockRootView.getParent()).thenReturn(mockParent);
+    when(mockManager.isEnabled()).thenReturn(true);
+
+    TestSemanticsNode root = new TestSemanticsNode();
+    root.id = 0;
+    TestSemanticsNode node1 = new TestSemanticsNode();
+    node1.id = 1;
+    node1.value = "some text";
+    node1.textSelectionBase = 0;
+    node1.textSelectionExtent = 0;
+    node1.addFlag(AccessibilityBridge.Flag.IS_TEXT_FIELD);
+    root.children.add(node1);
+    TestSemanticsUpdate testSemanticsUpdate = root.toUpdate();
+    testSemanticsUpdate.sendUpdateToBridge(accessibilityBridge);
+    Bundle bundle = new Bundle();
+    bundle.putInt(
+        AccessibilityNodeInfo.ACTION_ARGUMENT_MOVEMENT_GRANULARITY_INT,
+        AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER);
+    bundle.putBoolean(AccessibilityNodeInfo.ACTION_ARGUMENT_EXTEND_SELECTION_BOOLEAN, false);
+    accessibilityBridge.performAction(
+        1, AccessibilityNodeInfo.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY, bundle);
+    ArgumentCaptor<AccessibilityEvent> eventCaptor =
+        ArgumentCaptor.forClass(AccessibilityEvent.class);
+    verify(mockParent, times(1))
+        .requestSendAccessibilityEvent(eq(mockRootView), eventCaptor.capture());
+    assertEquals(eventCaptor.getAllValues().size(), 1);
+    AccessibilityEvent event = eventCaptor.getAllValues().get(0);
+    assertNotEquals(event.getEventType(), AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
+  }
+
   @Test
   public void itCanPredictCursorMovementsWithGranularityWordUnicode() {
     AccessibilityChannel mockChannel = mock(AccessibilityChannel.class);