AndroidVelocityTracker.h (1304B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef mozilla_layers_AndroidVelocityTracker_h 8 #define mozilla_layers_AndroidVelocityTracker_h 9 10 #include <utility> 11 12 #include "Axis.h" 13 #include "mozilla/Maybe.h" 14 #include "nsTArray.h" 15 16 namespace mozilla { 17 namespace layers { 18 19 class AndroidVelocityTracker : public VelocityTracker { 20 public: 21 explicit AndroidVelocityTracker(); 22 void StartTracking(ParentLayerCoord aPos, TimeStamp aTimestamp) override; 23 Maybe<float> AddPosition(ParentLayerCoord aPos, 24 TimeStamp aTimestamp) override; 25 Maybe<float> ComputeVelocity(TimeStamp aTimestamp) override; 26 void Clear() override; 27 28 private: 29 // A queue of (timestamp, position) pairs; these are the historical 30 // positions at the given timestamps. 31 nsTArray<std::pair<TimeStamp, ParentLayerCoord>> mHistory; 32 // The last time an event was added to the tracker, or the null moment if no 33 // events have been added. 34 TimeStamp mLastEventTime; 35 }; 36 37 } // namespace layers 38 } // namespace mozilla 39 40 #endif