ui/compositor/compositor_observer.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_COMPOSITOR_COMPOSITOR_OBSERVER_H_
   6 #define UI_COMPOSITOR_COMPOSITOR_OBSERVER_H_
   7
   8 #include "ui/compositor/compositor_export.h"
   9
  10 namespace ui {
  11
  12 class Compositor;
  13
  14 // A compositor observer is notified when compositing completes.
  15 class COMPOSITOR_EXPORT CompositorObserver {
  16  public:
  17   // A commit proxies information from the main thread to the compositor
  18   // thread. It typically happens when some state changes that will require a
  19   // composite. In the multi-threaded case, many commits may happen between
  20   // two successive composites. In the single-threaded, a single commit
  21   // between two composites (just before the composite as part of the
  22   // composite cycle). If the compositor is locked, it will not send this
  23   // this signal.
  24   virtual void OnCompositingDidCommit(Compositor* compositor) = 0;
  25
  26   // Called when compositing started: it has taken all the layer changes into
  27   // account and has issued the graphics commands.
  28   virtual void OnCompositingStarted(Compositor* compositor) = 0;
  29
  30   // Called when compositing completes: the present to screen has completed.
  31   virtual void OnCompositingEnded(Compositor* compositor) = 0;
  32
  33   // Called when compositing is aborted (e.g. lost graphics context).
  34   virtual void OnCompositingAborted(Compositor* compositor) = 0;
  35
  36   // Called when the compositor lock state changes.
  37   virtual void OnCompositingLockStateChanged(Compositor* compositor) = 0;
  38
  39  protected:
  40   virtual ~CompositorObserver() {}
  41 };
  42
  43 }  // namespace ui
  44
  45 #endif  // UI_COMPOSITOR_COMPOSITOR_OBSERVER_H_