arc-a11y: Handle multiple windows in one task correctly

There are some cases that one task exposes multiple accessibility
windows in Android. After this change, non-root windows have a generic
container role instead of an application role so that while moving focus
between windows, ChromeVox won't announce entering or exiting the
application.

Also, we won't dispatch focus for non-focused windows. Each window has
a focused node, but previously all focus events are handled equally.
With this change, only the focused window is considered in the focus
handling logic.

AX-Relnotes: n/a.
Bug: b:150827488
Test: current unit tests pass.
Change-Id: Icd900ef1dcf84926240c6b55f000ba75a05e1ad8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2576227
Commit-Queue: Hiroki Sato <hirokisato@chromium.org>
Reviewed-by: Sara Kato <sarakato@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836987}

chrome/browser/chromeos/arc/accessibility/accessibility_info_data_wrapper.h

@@ -48,6 +48,7 @@ class AccessibilityInfoDataWrapper {
   virtual std::string ComputeAXName(bool do_recursive) const = 0;
   virtual void GetChildren(
       std::vector<AccessibilityInfoDataWrapper*>* children) const = 0;
+  virtual int32_t GetWindowId() const = 0;
 
  protected:
   AXTreeSourceArc* tree_source_;

chrome/browser/chromeos/arc/accessibility/accessibility_node_info_data_wrapper.cc

@@ -556,6 +556,10 @@ void AccessibilityNodeInfoDataWrapper::GetChildren(
     children->push_back(tree_source_->GetFromId(id));
 }
 
+int32_t AccessibilityNodeInfoDataWrapper::GetWindowId() const {
+  return node_ptr_->window_id;
+}
+
 bool AccessibilityNodeInfoDataWrapper::GetProperty(
     AXBooleanProperty prop) const {
   return arc::GetBooleanProperty(node_ptr_, prop);

chrome/browser/chromeos/arc/accessibility/accessibility_node_info_data_wrapper.h

@@ -42,6 +42,7 @@ class AccessibilityNodeInfoDataWrapper : public AccessibilityInfoDataWrapper {
   std::string ComputeAXName(bool do_recursive) const override;
   void GetChildren(
       std::vector<AccessibilityInfoDataWrapper*>* children) const override;
+  int32_t GetWindowId() const override;
 
   mojom::AccessibilityNodeInfoData* node() { return node_ptr_; }
 

chrome/browser/chromeos/arc/accessibility/accessibility_window_info_data_wrapper.cc

@@ -81,7 +81,13 @@ void AccessibilityWindowInfoDataWrapper::PopulateAXRole(
       out_data->role = ax::mojom::Role::kWindow;
       return;
     case mojom::AccessibilityWindowType::TYPE_APPLICATION:
+      if (tree_source_->GetRoot()->GetId() == GetId()) {
+        // Root of this task.
         out_data->role = ax::mojom::Role::kApplication;
+      } else {
+        // A part of the main window.
+        out_data->role = ax::mojom::Role::kGenericContainer;
+      }
       return;
     case mojom::AccessibilityWindowType::TYPE_INPUT_METHOD:
       out_data->role = ax::mojom::Role::kKeyboard;
@@ -166,6 +172,10 @@ void AccessibilityWindowInfoDataWrapper::GetChildren(
     children->push_back(tree_source_->GetFromId(window_ptr_->root_node_id));
 }
 
+int32_t AccessibilityWindowInfoDataWrapper::GetWindowId() const {
+  return window_ptr_->window_id;
+}
+
 bool AccessibilityWindowInfoDataWrapper::GetProperty(
     mojom::AccessibilityWindowBooleanProperty prop) const {
   return arc::GetBooleanProperty(window_ptr_, prop);

chrome/browser/chromeos/arc/accessibility/accessibility_window_info_data_wrapper.h

@@ -40,6 +40,7 @@ class AccessibilityWindowInfoDataWrapper : public AccessibilityInfoDataWrapper {
   std::string ComputeAXName(bool do_recursive) const override;
   void GetChildren(
       std::vector<AccessibilityInfoDataWrapper*>* children) const override;
+  int32_t GetWindowId() const override;
 
  private:
   bool GetProperty(mojom::AccessibilityWindowBooleanProperty prop) const;

chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge_unittest.cc

@@ -337,20 +337,20 @@ TEST_F(ArcAccessibilityHelperBridgeTest, WindowIdTaskIdMapping) {
   event->event_type = arc::mojom::AccessibilityEventType::VIEW_FOCUSED;
   event->node_data.push_back(arc::mojom::AccessibilityNodeInfoData::New());
   event->node_data[0]->id = 10;
-  arc::SetProperty(event->node_data[0]->int_list_properties,
-                   mojom::AccessibilityIntListProperty::CHILD_NODE_IDS,
-                   {1, 2, 3});
+  event->node_data[0]->window_id = 100;
+  SetProperty(event->node_data[0]->int_list_properties,
+              mojom::AccessibilityIntListProperty::CHILD_NODE_IDS, {1, 2, 3});
   for (int i = 1; i <= 3; i++) {
     // This creates focusable nodes.
     // TODO(hirokisato): consider mock AXTreeSourceArc.
     event->node_data.push_back(arc::mojom::AccessibilityNodeInfoData::New());
     event->node_data[i]->id = i;
-    arc::SetProperty(event->node_data[i]->boolean_properties,
+    event->node_data[i]->window_id = 100;
+    SetProperty(event->node_data[i]->boolean_properties,
                 mojom::AccessibilityBooleanProperty::IMPORTANCE, true);
-    arc::SetProperty(event->node_data[i]->boolean_properties,
-                     mojom::AccessibilityBooleanProperty::VISIBLE_TO_USER,
-                     true);
-    arc::SetProperty(event->node_data[i]->string_properties,
+    SetProperty(event->node_data[i]->boolean_properties,
+                mojom::AccessibilityBooleanProperty::VISIBLE_TO_USER, true);
+    SetProperty(event->node_data[i]->string_properties,
                 mojom::AccessibilityStringProperty::CONTENT_DESCRIPTION,
                 "node" + base::NumberToString(i) + " description");
   }
@@ -361,6 +361,8 @@ TEST_F(ArcAccessibilityHelperBridgeTest, WindowIdTaskIdMapping) {
       event->window_data->back().get();
   root_window->window_id = 100;
   root_window->root_node_id = 10;
+  SetProperty(root_window->boolean_properties,
+              mojom::AccessibilityWindowBooleanProperty::FOCUSED, true);
 
   // There's no active window.
   helper_bridge->OnAccessibilityEvent(event.Clone());

chrome/browser/chromeos/arc/accessibility/arc_accessibility_util.h

@@ -36,7 +36,7 @@ std::string ToLiveStatusString(mojom::AccessibilityLiveRegionType type);
 
 template <class DataType, class PropType>
 bool GetBooleanProperty(DataType* node, PropType prop) {
-  if (!node->boolean_properties)
+  if (!node || !node->boolean_properties)
     return false;
 
   auto it = node->boolean_properties->find(prop);

chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.cc

@@ -31,6 +31,7 @@ using AXEventType = mojom::AccessibilityEventType;
 using AXIntProperty = mojom::AccessibilityIntProperty;
 using AXIntListProperty = mojom::AccessibilityIntListProperty;
 using AXNodeInfoData = mojom::AccessibilityNodeInfoData;
+using AXWindowBooleanProperty = mojom::AccessibilityWindowBooleanProperty;
 using AXWindowInfoData = mojom::AccessibilityWindowInfoData;
 using AXWindowIntListProperty = mojom::AccessibilityWindowIntListProperty;
 
@@ -396,9 +397,20 @@ AXTreeSourceArc::GetSelectedNodeInfoFromAdapterView(
 }
 
 bool AXTreeSourceArc::UpdateAndroidFocusedId(const AXEventData& event_data) {
+  AccessibilityInfoDataWrapper* source_node = GetFromId(event_data.source_id);
+  if (source_node) {
+    AccessibilityInfoDataWrapper* source_window =
+        GetFromId(source_node->GetWindowId());
+    if (!source_window ||
+        !GetBooleanProperty(source_window->GetWindow(),
+                            AXWindowBooleanProperty::FOCUSED)) {
+      // Don't update focus in this task for events from non-focused window.
+      return true;
+    }
+  }
+
   // TODO(hirokisato): Handle CLEAR_ACCESSIBILITY_FOCUS event.
   if (event_data.event_type == AXEventType::VIEW_FOCUSED) {
-    AccessibilityInfoDataWrapper* source_node = GetFromId(event_data.source_id);
     if (source_node && source_node->IsVisibleToUser()) {
       // Sometimes Android sets focus on unfocusable node, e.g. ListView.
       AccessibilityInfoDataWrapper* adjusted_node =
@@ -410,14 +422,12 @@ bool AXTreeSourceArc::UpdateAndroidFocusedId(const AXEventData& event_data) {
     }
   } else if (event_data.event_type == AXEventType::VIEW_ACCESSIBILITY_FOCUSED &&
              UseFullFocusMode()) {
-    AccessibilityInfoDataWrapper* source_node = GetFromId(event_data.source_id);
     if (source_node && source_node->IsVisibleToUser())
       android_focused_id_ = source_node->GetId();
   } else if (event_data.event_type == AXEventType::VIEW_SELECTED) {
     // In Android, VIEW_SELECTED event is dispatched in the two cases below:
     // 1. Changing a value in ProgressBar or TimePicker in ARC P.
     // 2. Selecting an item in the context of an AdapterView.
-    AccessibilityInfoDataWrapper* source_node = GetFromId(event_data.source_id);
     if (!source_node || !source_node->IsNode())
       return false;
 
@@ -438,7 +448,6 @@ bool AXTreeSourceArc::UpdateAndroidFocusedId(const AXEventData& event_data) {
     // is fired from Android multiple times.
     // The event of WINDOW_STATE_CHANGED is fired only once for each window
     // change and use it as a trigger to move the a11y focus to the first node.
-    AccessibilityInfoDataWrapper* source_node = GetFromId(event_data.source_id);
     AccessibilityInfoDataWrapper* new_focus = nullptr;
 
     // If the current window has ever been visited in the current task, try