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_ 57
