cc/scheduler/vsync_time_source.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 CC_SCHEDULER_VSYNC_TIME_SOURCE_H_
   6 #define CC_SCHEDULER_VSYNC_TIME_SOURCE_H_
   7
   8 #include "cc/base/cc_export.h"
   9 #include "cc/scheduler/time_source.h"
  10
  11 namespace cc {
  12
  13 class CC_EXPORT VSyncClient {
  14  public:
  15   virtual void DidVSync(base::TimeTicks frame_time) = 0;
  16
  17  protected:
  18   virtual ~VSyncClient() {}
  19 };
  20
  21 class VSyncProvider {
  22  public:
  23   // Request to be notified of future vsync events. The notifications will be
  24   // delivered until they are disabled by calling this function with a null
  25   // client.
  26   virtual void RequestVSyncNotification(VSyncClient* client) = 0;
  27
  28  protected:
  29   virtual ~VSyncProvider() {}
  30 };
  31
  32 // This timer implements a time source that is explicitly triggered by an
  33 // external vsync signal.
  34 class CC_EXPORT VSyncTimeSource : public TimeSource, public VSyncClient {
  35  public:
  36   static scoped_refptr<VSyncTimeSource> Create(VSyncProvider* vsync_provider);
  37
  38   // TimeSource implementation
  39   virtual void SetClient(TimeSourceClient* client) OVERRIDE;
  40   virtual void SetTimebaseAndInterval(base::TimeTicks timebase,
  41                                       base::TimeDelta interval) OVERRIDE;
  42   virtual void SetActive(bool active) OVERRIDE;
  43   virtual bool Active() const OVERRIDE;
  44   virtual base::TimeTicks LastTickTime() OVERRIDE;
  45   virtual base::TimeTicks NextTickTime() OVERRIDE;
  46
  47   // VSyncClient implementation
  48   virtual void DidVSync(base::TimeTicks frame_time) OVERRIDE;
  49
  50  protected:
  51   explicit VSyncTimeSource(VSyncProvider* vsync_provider);
  52   virtual ~VSyncTimeSource();
  53
  54   base::TimeTicks last_tick_time_;
  55   base::TimeDelta interval_;
  56   bool active_;
  57   bool notification_requested_;
  58
  59   VSyncProvider* vsync_provider_;
  60   TimeSourceClient* client_;
  61
  62   DISALLOW_COPY_AND_ASSIGN(VSyncTimeSource);
  63 };
  64
  65 }  // namespace cc
  66
  67 #endif  // CC_SCHEDULER_VSYNC_TIME_SOURCE_H_