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 "base/time/time.h"
   9 #include "ui/compositor/compositor_export.h"
  10
  11 namespace ui {
  12
  13 class Compositor;
  14
  15 // A compositor observer is notified when compositing completes.
  16 class COMPOSITOR_EXPORT CompositorObserver {
  17  public:
  18   CompositorObserver();
  19
  20   // A commit proxies information from the main thread to the compositor
  21   // thread. It typically happens when some state changes that will require a
  22   // composite. In the multi-threaded case, many commits may happen between
  23   // two successive composites. In the single-threaded, a single commit
  24   // between two composites (just before the composite as part of the
  25   // composite cycle). If the compositor is locked, it will not send this
  26   // this signal.
  27   virtual void OnCompositingDidCommit(Compositor* compositor) = 0;
  28
  29   // Called when compositing started: it has taken all the layer changes into
  30   // account and has issued the graphics commands.
  31   virtual void OnCompositingStarted(Compositor* compositor,
  32                                     base::TimeTicks start_time) = 0;
  33
  34   // Called when compositing completes: the present to screen has completed.
  35   virtual void OnCompositingEnded(Compositor* compositor) = 0;
  36
  37   // Called when compositing is aborted (e.g. lost graphics context).
  38   virtual void OnCompositingAborted(Compositor* compositor) = 0;
  39
  40   // Called when the compositor lock state changes.
  41   virtual void OnCompositingLockStateChanged(Compositor* compositor) = 0;
  42
  43  protected:
  44 #if defined(OS_MACOSX)
  45   // Debugging instrumentation for crbug.com/401630.
  46   // TODO(ccameron): remove this.
  47   friend class Compositor;
  48   int32 observing_count_;
  49 #endif
  50
  51   virtual ~CompositorObserver();
  52 };
  53
  54 }  // namespace ui
  55
  56 #endif  // UI_COMPOSITOR_COMPOSITOR_OBSERVER_H_