ui/views/widget/desktop_aura/desktop_capture_client.h

   1 // Copyright 2013 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_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_CAPTURE_CLIENT_H_
   6 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_CAPTURE_CLIENT_H_
   7
   8 #include <set>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "ui/aura/client/capture_client.h"
  13 #include "ui/views/views_export.h"
  14
  15 namespace aura {
  16 class RootWindow;
  17 }
  18
  19 namespace views {
  20
  21 // Desktop implementation of CaptureClient. There is one CaptureClient per
  22 // DesktopNativeWidgetAura.
  23 //
  24 // DesktopCaptureClient and CaptureController (used by ash) differ slightly in
  25 // how they handle capture. CaptureController is a singleton shared among all
  26 // RootWindows created by ash. An implication of this is that all RootWindows
  27 // know which window has capture. This is not the case with
  28 // DesktopCaptureClient. Instead each RootWindow has its own
  29 // DesktopCaptureClient. This means only the RootWindow of the Window that has
  30 // capture knows which window has capture. All others think no one has
  31 // capture. This behavior is necessitated by Windows occassionally delivering
  32 // mouse events to a window other than the capture window and expecting that
  33 // window to get the event. If we shared the capture window on the desktop this
  34 // behavior would not be possible.
  35 class VIEWS_EXPORT DesktopCaptureClient : public aura::client::CaptureClient {
  36  public:
  37   explicit DesktopCaptureClient(aura::Window* root);
  38   virtual ~DesktopCaptureClient();
  39
  40   // Overridden from aura::client::CaptureClient:
  41   virtual void SetCapture(aura::Window* window) OVERRIDE;
  42   virtual void ReleaseCapture(aura::Window* window) OVERRIDE;
  43   virtual aura::Window* GetCaptureWindow() OVERRIDE;
  44   virtual aura::Window* GetGlobalCaptureWindow() OVERRIDE;
  45
  46  private:
  47   typedef std::set<DesktopCaptureClient*> CaptureClients;
  48
  49   aura::Window* root_;
  50   aura::Window* capture_window_;
  51
  52   // Set of DesktopCaptureClients.
  53   static CaptureClients* capture_clients_;
  54
  55   DISALLOW_COPY_AND_ASSIGN(DesktopCaptureClient);
  56 };
  57
  58 }  // namespace views
  59
  60 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_CAPTURE_CLIENT_H_