ui/aura/client/event_client.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_AURA_CLIENT_EVENT_CLIENT_H_
   6 #define UI_AURA_CLIENT_EVENT_CLIENT_H_
   7
   8 #include "ui/aura/aura_export.h"
   9
  10 namespace ui {
  11 class EventTarget;
  12 }
  13
  14 namespace aura {
  15 class Window;
  16 namespace client {
  17
  18 // An interface implemented by an object that alters event processing.
  19 class AURA_EXPORT EventClient {
  20  public:
  21   // Returns true if events can be processed by |window| or any of its children.
  22   virtual bool CanProcessEventsWithinSubtree(const Window* window) const = 0;
  23
  24   // Returns the top level EventTarget for the current environment.
  25   virtual ui::EventTarget* GetToplevelEventTarget() = 0;
  26
  27  protected:
  28   virtual ~EventClient() {}
  29 };
  30
  31 // Sets/Gets the event client on the root Window.
  32 AURA_EXPORT void SetEventClient(Window* root_window, EventClient* client);
  33 AURA_EXPORT EventClient* GetEventClient(const Window* root_window);
  34
  35 }  // namespace clients
  36 }  // namespace aura
  37
  38 #endif  // UI_AURA_CLIENT_EVENT_CLIENT_H_