1 // Copyright 2011 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_TIME_SOURCE_H_ 6 #define CC_SCHEDULER_TIME_SOURCE_H_ 7 8 #include "base/memory/ref_counted.h" 9 #include "base/time/time.h" 10 #include "cc/base/cc_export.h" 11 12 namespace cc { 13 14 class TimeSourceClient { 15 public: 16 virtual void OnTimerTick() = 0; 17 18 protected: ~TimeSourceClient()19 virtual ~TimeSourceClient() {} 20 }; 21 22 // An generic interface for getting a reliably-ticking timesource of 23 // a specified rate. 24 // 25 // Be sure to call SetActive(false) before releasing your reference to the 26 // timer, or it will keep on ticking! 27 class CC_EXPORT TimeSource : public base::RefCounted<TimeSource> { 28 public: 29 virtual void SetClient(TimeSourceClient* client) = 0; 30 31 // If transitioning from not active to active, SetActive will return the 32 // timestamp of the most recenly missed tick that did not have OnTimerTick 33 // called. 34 virtual base::TimeTicks SetActive(bool active) = 0; 35 36 virtual bool Active() const = 0; 37 virtual void SetTimebaseAndInterval(base::TimeTicks timebase, 38 base::TimeDelta interval) = 0; 39 virtual base::TimeTicks LastTickTime() = 0; 40 virtual base::TimeTicks NextTickTime() = 0; 41 42 protected: ~TimeSource()43 virtual ~TimeSource() {} 44 45 private: 46 friend class base::RefCounted<TimeSource>; 47 }; 48 49 } // namespace cc 50 51 #endif // CC_SCHEDULER_TIME_SOURCE_H_ 52