/* * Copyright (C) 2015 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef WheelEventDeltaFilter_h #define WheelEventDeltaFilter_h #include "FloatSize.h" #include <wtf/Deque.h> namespace WebCore { class PlatformWheelEvent; class WheelEventDeltaFilter { public: WheelEventDeltaFilter(); virtual ~WheelEventDeltaFilter(); WEBCORE_EXPORT static std::unique_ptr<WheelEventDeltaFilter> create(); WEBCORE_EXPORT virtual void updateFromDelta(const FloatSize&) = 0; WEBCORE_EXPORT virtual void beginFilteringDeltas() = 0; WEBCORE_EXPORT virtual void endFilteringDeltas() = 0; WEBCORE_EXPORT bool isFilteringDeltas() const; WEBCORE_EXPORT FloatSize filteredDelta() const; protected: FloatSize m_currentFilteredDelta; bool m_isFilteringDeltas { false }; }; enum class DominantScrollGestureDirection { None, Vertical, Horizontal }; class BasicWheelEventDeltaFilter final : public WheelEventDeltaFilter { public: BasicWheelEventDeltaFilter(); void updateFromDelta(const FloatSize&) override; void beginFilteringDeltas() override; void endFilteringDeltas() override; private: DominantScrollGestureDirection dominantScrollGestureDirection() const; Deque<FloatSize> m_recentWheelEventDeltas; }; } #endif