1 /* 2 * Copyright (c) 2010, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef ScrollAnimator_h 32 #define ScrollAnimator_h 33 34 #include "core/platform/PlatformWheelEvent.h" 35 #include "core/platform/ScrollTypes.h" 36 #include "core/platform/graphics/FloatSize.h" 37 #include "wtf/FastAllocBase.h" 38 #include "wtf/Forward.h" 39 #include "wtf/UnusedParam.h" 40 41 namespace WebCore { 42 43 class FloatPoint; 44 class ScrollableArea; 45 class Scrollbar; 46 47 class ScrollAnimator { 48 WTF_MAKE_FAST_ALLOCATED; 49 public: 50 static PassOwnPtr<ScrollAnimator> create(ScrollableArea*); 51 52 virtual ~ScrollAnimator(); 53 54 // Computes a scroll destination for the given parameters. Returns false if 55 // already at the destination. Otherwise, starts scrolling towards the 56 // destination and returns true. Scrolling may be immediate or animated. 57 // The base class implementation always scrolls immediately, never animates. 58 virtual bool scroll(ScrollbarOrientation, ScrollGranularity, float step, float multiplier); 59 60 virtual void scrollToOffsetWithoutAnimation(const FloatPoint&); 61 62 ScrollableArea* scrollableArea() const { return m_scrollableArea; } 63 64 virtual void setIsActive() { } 65 66 virtual bool handleWheelEvent(const PlatformWheelEvent&); 67 68 #if OS(DARWIN) 69 virtual void handleWheelEventPhase(PlatformWheelEventPhase) { } 70 #endif 71 72 void setCurrentPosition(const FloatPoint&); 73 FloatPoint currentPosition() const; 74 75 virtual void cancelAnimations() { } 76 virtual void serviceScrollAnimations() { } 77 78 virtual void contentAreaWillPaint() const { } 79 virtual void mouseEnteredContentArea() const { } 80 virtual void mouseExitedContentArea() const { } 81 virtual void mouseMovedInContentArea() const { } 82 virtual void mouseEnteredScrollbar(Scrollbar*) const { } 83 virtual void mouseExitedScrollbar(Scrollbar*) const { } 84 virtual void willStartLiveResize() { } 85 virtual void contentsResized() const { } 86 virtual void willEndLiveResize() { } 87 virtual void contentAreaDidShow() const { } 88 virtual void contentAreaDidHide() const { } 89 90 virtual void finishCurrentScrollAnimations() { } 91 92 virtual void didAddVerticalScrollbar(Scrollbar*) { } 93 virtual void willRemoveVerticalScrollbar(Scrollbar*) { } 94 virtual void didAddHorizontalScrollbar(Scrollbar*) { } 95 virtual void willRemoveHorizontalScrollbar(Scrollbar*) { } 96 97 virtual bool shouldScrollbarParticipateInHitTesting(Scrollbar*) { return true; } 98 99 virtual void notifyContentAreaScrolled(const FloatSize& delta) { UNUSED_PARAM(delta); } 100 101 virtual bool isRubberBandInProgress() const { return false; } 102 103 protected: 104 explicit ScrollAnimator(ScrollableArea*); 105 106 virtual void notifyPositionChanged(const FloatSize& delta); 107 108 ScrollableArea* m_scrollableArea; 109 float m_currentPosX; // We avoid using a FloatPoint in order to reduce 110 float m_currentPosY; // subclass code complexity. 111 112 private: 113 float clampScrollPosition(ScrollbarOrientation, float); 114 }; 115 116 } // namespace WebCore 117 118 #endif // ScrollAnimator_h 119