| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_ |
| #define UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_ |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/observer_list.h" |
| #include "base/synchronization/lock.h" |
| #include "base/time/time.h" |
| #include "ui/compositor/compositor_export.h" |
| |
| namespace ui { |
| |
| // This class manages vsync parameters for a compositor. It merges updates of |
| // the parameters from different sources and sends the merged updates to |
| // observers which register to it. |
| class COMPOSITOR_EXPORT CompositorVSyncManager |
| : public base::RefCounted<CompositorVSyncManager> { |
| public: |
| class Observer { |
| public: |
| virtual ~Observer() = default; |
| virtual void OnUpdateVSyncParameters(base::TimeTicks timebase, |
| base::TimeDelta interval) = 0; |
| }; |
| |
| CompositorVSyncManager(); |
| |
| // The vsync parameters consist of |timebase|, which is the platform timestamp |
| // of the last vsync, and |interval|, which is the interval between vsyncs. |
| void UpdateVSyncParameters(base::TimeTicks timebase, |
| base::TimeDelta interval); |
| |
| void AddObserver(Observer* observer); |
| void RemoveObserver(Observer* observer); |
| |
| private: |
| friend class base::RefCounted<CompositorVSyncManager>; |
| |
| ~CompositorVSyncManager(); |
| |
| void NotifyObservers(base::TimeTicks timebase, base::TimeDelta interval); |
| |
| base::ObserverList<Observer>::Unchecked observer_list_; |
| |
| base::TimeTicks last_timebase_; |
| base::TimeDelta last_interval_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CompositorVSyncManager); |
| }; |
| |
| } // namespace ui |
| |
| #endif // UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_ |