a11y: Announce changes to cursor position on Android (flutter#4587)

kjpou1 · Jan 25, 2018 · 4c82c56 · 4c82c56
1 parent 93296fb
commit 4c82c56
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Showing 6 changed files with 39 additions and 24 deletions.
diff --git a/lib/ui/semantics.dart b/lib/ui/semantics.dart
@@ -293,7 +293,7 @@ class SemanticsUpdateBuilder extends NativeFieldWrapperClass2 {
   /// string describes what result an action performed on this node has. The
   /// reading direction of all these strings is given by `textDirection`.
   ///
-  /// The fields 'textSelectionStart' and 'textSelectionEnd' describe the
+  /// The fields 'textSelectionBase' and 'textSelectionExtent' describe the
   /// currently selected text within `value`.
   ///
   /// The `rect` is the region occupied by this node in its own coordinate
@@ -305,8 +305,8 @@ class SemanticsUpdateBuilder extends NativeFieldWrapperClass2 {
     int id,
     int flags,
     int actions,
-    int textSelectionStart,
-    int textSelectionEnd,
+    int textSelectionBase,
+    int textSelectionExtent,
     Rect rect,
     String label,
     String hint,
@@ -323,8 +323,8 @@ class SemanticsUpdateBuilder extends NativeFieldWrapperClass2 {
       id,
       flags,
       actions,
-      textSelectionStart,
-      textSelectionEnd,
+      textSelectionBase,
+      textSelectionExtent,
       rect.left,
       rect.top,
       rect.right,
@@ -343,8 +343,8 @@ class SemanticsUpdateBuilder extends NativeFieldWrapperClass2 {
     int id,
     int flags,
     int actions,
-    int textSelectionStart,
-    int textSelectionEnd,
+    int textSelectionBase,
+    int textSelectionExtent,
     double left,
     double top,
     double right,

diff --git a/lib/ui/semantics/semantics_node.h b/lib/ui/semantics/semantics_node.h
@@ -55,8 +55,8 @@ struct SemanticsNode {
   int32_t id = 0;
   int32_t flags = 0;
   int32_t actions = 0;
-  int32_t textSelectionStart = -1;
-  int32_t textSelectionEnd = -1;
+  int32_t textSelectionBase = -1;
+  int32_t textSelectionExtent = -1;
   std::string label;
   std::string hint;
   std::string value;

diff --git a/lib/ui/semantics/semantics_update_builder.cc b/lib/ui/semantics/semantics_update_builder.cc
@@ -37,8 +37,8 @@ SemanticsUpdateBuilder::~SemanticsUpdateBuilder() = default;
 void SemanticsUpdateBuilder::updateNode(int id,
                                         int flags,
                                         int actions,
-                                        int textSelectionStart,
-                                        int textSelectionEnd,
+                                        int textSelectionBase,
+                                        int textSelectionExtent,
                                         double left,
                                         double top,
                                         double right,
@@ -55,8 +55,8 @@ void SemanticsUpdateBuilder::updateNode(int id,
   node.id = id;
   node.flags = flags;
   node.actions = actions;
-  node.textSelectionStart = textSelectionStart;
-  node.textSelectionEnd = textSelectionEnd;
+  node.textSelectionBase = textSelectionBase;
+  node.textSelectionExtent = textSelectionExtent;
   node.rect = SkRect::MakeLTRB(left, top, right, bottom);
   node.label = label;
   node.hint = hint;

diff --git a/lib/ui/semantics/semantics_update_builder.h b/lib/ui/semantics/semantics_update_builder.h
@@ -28,8 +28,8 @@ class SemanticsUpdateBuilder
   void updateNode(int id,
                   int flags,
                   int actions,
-                  int textSelectionStart,
-                  int textSelectionEnd,
+                  int textSelectionBase,
+                  int textSelectionExtent,
                   double left,
                   double top,
                   double right,

diff --git a/shell/platform/android/io/flutter/view/AccessibilityBridge.java b/shell/platform/android/io/flutter/view/AccessibilityBridge.java
@@ -125,8 +125,8 @@ public AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualViewId) {
             result.setClassName("android.widget.EditText");
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
                 result.setEditable(true);
-                if (object.textSelectionStart != -1 && object.textSelectionEnd != -1) {
-                    result.setTextSelection(object.textSelectionStart, object.textSelectionEnd);
+                if (object.textSelectionBase != -1 && object.textSelectionExtent != -1) {
+                    result.setTextSelection(object.textSelectionBase, object.textSelectionExtent);
                 }
             }
 
@@ -460,6 +460,17 @@ void updateSemantics(ByteBuffer buffer, String[] strings) {
                 if (event != null) {
                     sendAccessibilityEvent(event);
                 }
+
+                if (object.previousTextSelectionBase != object.textSelectionBase
+                        || object.previousTextSelectionExtent != object.textSelectionExtent) {
+                    AccessibilityEvent selectionEvent = obtainAccessibilityEvent(
+                        object.id, AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
+                    selectionEvent.getText().add(newValue);
+                    selectionEvent.setFromIndex(object.textSelectionBase);
+                    selectionEvent.setToIndex(object.previousTextSelectionExtent);
+                    selectionEvent.setItemCount(newValue.length());
+                    sendAccessibilityEvent(selectionEvent);
+                }
             }
         }
     }
@@ -603,8 +614,8 @@ private class SemanticsObject {
 
         int flags;
         int actions;
-        int textSelectionStart;
-        int textSelectionEnd;
+        int textSelectionBase;
+        int textSelectionExtent;
         String label;
         String value;
         String increasedValue;
@@ -614,6 +625,8 @@ private class SemanticsObject {
 
         boolean hadPreviousConfig = false;
         int previousFlags;
+        int previousTextSelectionBase;
+        int previousTextSelectionExtent;
         String previousValue;
 
         private float left;
@@ -658,14 +671,16 @@ void log(String indent) {
         }
 
         void updateWith(ByteBuffer buffer, String[] strings) {
+            hadPreviousConfig = true;
             previousValue = value;
             previousFlags = flags;
-            hadPreviousConfig = true;
+            previousTextSelectionBase = textSelectionBase;
+            previousTextSelectionExtent = textSelectionExtent;
 
             flags = buffer.getInt();
             actions = buffer.getInt();
-            textSelectionStart = buffer.getInt();
-            textSelectionEnd = buffer.getInt();
+            textSelectionBase = buffer.getInt();
+            textSelectionExtent = buffer.getInt();
 
             int stringIndex = buffer.getInt();
             label = stringIndex == -1 ? null : strings[stringIndex];

diff --git a/shell/platform/android/platform_view_android.cc b/shell/platform/android/platform_view_android.cc
@@ -488,8 +488,8 @@ void PlatformViewAndroid::UpdateSemantics(
       buffer_int32[position++] = node.id;
       buffer_int32[position++] = node.flags;
       buffer_int32[position++] = node.actions;
-      buffer_int32[position++] = node.textSelectionStart;
-      buffer_int32[position++] = node.textSelectionEnd;
+      buffer_int32[position++] = node.textSelectionBase;
+      buffer_int32[position++] = node.textSelectionExtent;
       if (node.label.empty()) {
         buffer_int32[position++] = -1;
       } else {