Draw underlay behind android apps using talkback

components/exo/shell_surface.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_EXO_SHELL_SURFACE_H_
 #define COMPONENTS_EXO_SHELL_SURFACE_H_
 
 #include <deque>
 #include <memory>
 #include <string>
 
+#include "ash/common/system/accessibility_observer.h"
 #include "ash/common/wm/window_state_observer.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/exo/surface_delegate.h"
 #include "components/exo/surface_observer.h"
 #include "components/exo/wm_helper.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/hit_test.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
@@ skipping 13 matching lines @@
 namespace exo {
 class Surface;
 
 // This class provides functions for treating a surfaces like toplevel,
 // fullscreen or popup widgets, move, resize or maximize them, associate
 // metadata like title and class, etc.
 class ShellSurface : public SurfaceDelegate,
                      public SurfaceObserver,
                      public views::WidgetDelegate,
                      public views::View,
+                     public ash::AccessibilityObserver,
                      public ash::wm::WindowStateObserver,
                      public aura::WindowObserver,
                      public WMHelper::ActivationObserver {
  public:
   ShellSurface(Surface* surface,
                ShellSurface* parent,
                const gfx::Rect& initial_bounds,
                bool activatable,
                int container);
   explicit ShellSurface(Surface* surface);
@@ skipping 132 matching lines @@
   const views::Widget* GetWidget() const override;
   views::View* GetContentsView() override;
   views::NonClientFrameView* CreateNonClientFrameView(
       views::Widget* widget) override;
   bool WidgetHasHitTestMask() const override;
   void GetWidgetHitTestMask(gfx::Path* mask) const override;
 
   // Overridden from views::View:
   gfx::Size GetPreferredSize() const override;
 
+  // Overridden from ash::AccessibilityObserver:
+  void OnAccessibilityModeChanged(
+      ash::AccessibilityNotificationVisibility notify) override;
+
   // Overridden from ash::wm::WindowStateObserver:
   void OnPreWindowStateTypeChange(ash::wm::WindowState* window_state,
                                   ash::wm::WindowStateType old_type) override;
   void OnPostWindowStateTypeChange(ash::wm::WindowState* window_state,
                                    ash::wm::WindowStateType old_type) override;
 
   // Overridden from aura::WindowObserver:
   void OnWindowBoundsChanged(aura::Window* window,
                              const gfx::Rect& old_bounds,
                              const gfx::Rect& new_bounds) override;
   void OnWindowDestroying(aura::Window* window) override;
 
   // Overridden from WMHelper::ActivationObserver:
   void OnWindowActivated(
       aura::Window* gained_active,
       aura::Window* lost_active) override;
 
   // Overridden from ui::EventHandler:
+  void OnEvent(ui::Event* event) override;
   void OnKeyEvent(ui::KeyEvent* event) override;
   void OnMouseEvent(ui::MouseEvent* event) override;
 
   // Overridden from ui::AcceleratorTarget:
   bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
 
   const aura::Window* shadow_underlay_for_test() const {
     return shadow_underlay_;
   }
 
@@ skipping 66 matching lines @@
   int pending_resize_component_ = HTCAPTION;
   aura::Window* shadow_overlay_ = nullptr;
   aura::Window* shadow_underlay_ = nullptr;
   gfx::Rect shadow_content_bounds_;
   std::deque<Config> pending_configs_;
   std::unique_ptr<ash::WindowResizer> resizer_;
   std::unique_ptr<ScopedAnimationsDisabled> scoped_animations_disabled_;
   int top_inset_height_ = 0;
   int pending_top_inset_height_ = 0;
   float rectangular_shadow_background_opacity_ = 1.0;
+  bool audio_feedback_ = false;

[reveman, 2016/09/28 16:11:51]

Does this state need to be cached here? Can we just use
ash::WmShell::Get()->accessibility_delegate()->IsSpokenFeedbackEnabled()
directly where needed instead?

[erosky, 2016/09/28 19:21:13]

Done.

 
   DISALLOW_COPY_AND_ASSIGN(ShellSurface);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_SHELL_SURFACE_H_