Improves focus/activation for aura-mus and DesktopNativeWidgetAura

ui/aura/env.h

 // Copyright (c) 2012 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 UI_AURA_ENV_H_
 #define UI_AURA_ENV_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/supports_user_data.h"
 #include "ui/aura/aura_export.h"
 #include "ui/events/event_handler.h"
 #include "ui/events/event_target.h"
 #include "ui/gfx/geometry/point.h"
 
 namespace ui {
 class ContextFactory;
 class PlatformEventSource;
 }
 namespace aura {
 
+namespace client {
+class FocusClient;
+}
+
 namespace test {
 class EnvTestHelper;
 }
 
 class EnvObserver;
 class InputStateLookup;
 class Window;
 class WindowPort;
 class WindowTreeHost;
 
@@ skipping 32 matching lines @@
 
   // Whether any touch device is currently down.
   bool is_touch_down() const { return is_touch_down_; }
   void set_touch_down(bool value) { is_touch_down_ = value; }
 
   void set_context_factory(ui::ContextFactory* context_factory) {
     context_factory_ = context_factory;
   }
   ui::ContextFactory* context_factory() { return context_factory_; }
 
+  // Sets the active FocusClient and the window the FocusClient is associated
+  // with. |window| is not necessarily the window that actually has focus.
+  // |window| may be null, which indicates all windows share a FocusClient.
+  void SetActiveFocusClient(client::FocusClient* focus_client,
+                            Window* focus_client_root);
+  client::FocusClient* active_focus_client() { return active_focus_client_; }
+  Window* active_focus_client_root() { return active_focus_client_root_; }
+
  private:
+  class ActiveFocusClientWindowObserver;
+
   friend class test::EnvTestHelper;
   friend class Window;
   friend class WindowTreeHost;
 
   explicit Env(const WindowPortFactory& window_port_factory);
 
   void Init();
 
   // Called by the Window when it is initialized. Notifies observers.
   void NotifyWindowInitialized(Window* window);
 
   // Called by the WindowTreeHost when it is initialized. Notifies observers.
   void NotifyHostInitialized(WindowTreeHost* host);
 
   // Invoked by WindowTreeHost when it is activated. Notifies observers.
   void NotifyHostActivated(WindowTreeHost* host);
 
+  void OnActiveFocusClientWindowDestroying();
+
   // Overridden from ui::EventTarget:
   bool CanAcceptEvent(const ui::Event& event) override;
   ui::EventTarget* GetParentTarget() override;
   std::unique_ptr<ui::EventTargetIterator> GetChildIterator() const override;
   ui::EventTargeter* GetEventTargeter() override;
 
   WindowPortFactory window_port_factory_;
 
   base::ObserverList<EnvObserver> observers_;
 
   int mouse_button_flags_;
   // Location of last mouse event, in screen coordinates.
   gfx::Point last_mouse_location_;
   bool is_touch_down_;
 
   std::unique_ptr<InputStateLookup> input_state_lookup_;
   std::unique_ptr<ui::PlatformEventSource> event_source_;
 
   ui::ContextFactory* context_factory_;
 
+  Window* active_focus_client_root_ = nullptr;
+  client::FocusClient* active_focus_client_ = nullptr;
+  std::unique_ptr<ActiveFocusClientWindowObserver>
+      active_focus_client_window_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(Env);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_ENV_H_