Fix Chrome OS virtual keyboard accessibility

ui/views/accessibility/ax_window_obj_wrapper.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/accessibility/ax_window_obj_wrapper.h"
 
 #include <stddef.h>
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
@@ skipping 36 matching lines @@
   if (widget && widget->IsVisible())
     out_children->push_back(AXAuraObjCache::GetInstance()->GetOrCreate(widget));
 }
 
 void AXWindowObjWrapper::Serialize(ui::AXNodeData* out_node_data) {
   out_node_data->id = GetID();
   out_node_data->role = is_alert_ ? ui::AX_ROLE_ALERT : ui::AX_ROLE_WINDOW;
   out_node_data->AddStringAttribute(ui::AX_ATTR_NAME,
                                     base::UTF16ToUTF8(window_->GetTitle()));
   out_node_data->state = 0;
-  out_node_data->location = gfx::RectF(window_->bounds());
+  out_node_data->location = gfx::RectF(window_->GetBoundsInScreen());
 
   ui::AXTreeIDRegistry::AXTreeID child_ax_tree_id =
       window_->GetProperty(ui::kChildAXTreeID);
-  if (child_ax_tree_id != ui::AXTreeIDRegistry::kNoAXTreeID)
+  if (child_ax_tree_id != ui::AXTreeIDRegistry::kNoAXTreeID) {
+    // Most often, child AX trees are parented to Views. We need to handle
+    // the case where they're not here, but we don't want the same AX tree
+    // to be a child of two different parents.
+    //
+    // To avoid this double-parenting, only add the child tree ID of this
+    // window if the top-level window doesn't have an associated Widget.
+    if (!window_->GetToplevelWindow() ||

[David Tseng, 2017/04/27 23:03:12]

What about this first case? Do we want to add the child tree if the window has
no top level window?

[dmazzoni, 2017/04/27 23:20:15]

I don't think that should ever happen for a legit reason, but
maybe during teardown.

+        Widget::GetWidgetForNativeView(window_->GetToplevelWindow())) {
+      return;
+    }
+
     out_node_data->AddIntAttribute(ui::AX_ATTR_CHILD_TREE_ID, child_ax_tree_id);
+  }
 }
 
 int32_t AXWindowObjWrapper::GetID() {
   return AXAuraObjCache::GetInstance()->GetID(window_);
 }
 
 void AXWindowObjWrapper::OnWindowDestroyed(aura::Window* window) {
   AXAuraObjCache::GetInstance()->Remove(window, nullptr);
 }
 
 void AXWindowObjWrapper::OnWindowDestroying(aura::Window* window) {
   Widget* widget = Widget::GetWidgetForNativeView(window);
   if (widget)
     AXAuraObjCache::GetInstance()->Remove(widget);
 }
 
 void AXWindowObjWrapper::OnWindowHierarchyChanged(
     const HierarchyChangeParams& params) {
   if (params.phase == WindowObserver::HierarchyChangeParams::HIERARCHY_CHANGED)
     AXAuraObjCache::GetInstance()->Remove(params.target, params.old_parent);
 }
 
 void AXWindowObjWrapper::OnWindowBoundsChanged(aura::Window* window,
                                                const gfx::Rect& old_bounds,
                                                const gfx::Rect& new_bounds) {
+  AXAuraObjCache::GetInstance()->FireEvent(this, ui::AX_EVENT_LOCATION_CHANGED);
+
   Widget* widget = Widget::GetWidgetForNativeView(window);
   if (widget) {
     widget->GetRootView()->NotifyAccessibilityEvent(
         ui::AX_EVENT_LOCATION_CHANGED, true);
   }
 }
 
+void AXWindowObjWrapper::OnWindowPropertyChanged(aura::Window* window,
+                                                 const void* key,
+                                                 intptr_t old) {
+  if (key == ui::kChildAXTreeID) {
+    AXAuraObjCache::GetInstance()->FireEvent(this,

[David Tseng, 2017/04/27 23:03:12]

Is |this| always the wrapper for |window|?

[dmazzoni, 2017/04/27 23:20:15]

Good catch, added check for window_ == window

+                                             ui::AX_EVENT_CHILDREN_CHANGED);
+  }
+}
+
 }  // namespace views