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 "FloatSize.h" 35#include "PlatformWheelEvent.h" 36#include "ScrollTypes.h" 37#include <wtf/FastMalloc.h> 38#include <wtf/Forward.h> 39 40namespace WebCore { 41 42class FloatPoint; 43class PlatformTouchEvent; 44class ScrollableArea; 45class Scrollbar; 46 47class ScrollAnimator { 48 WTF_MAKE_FAST_ALLOCATED; 49public: 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 bool handleWheelEvent(const PlatformWheelEvent&); 65 66#if ENABLE(TOUCH_EVENTS) 67 virtual bool handleTouchEvent(const PlatformTouchEvent&); 68#endif 69 70#if PLATFORM(COCOA) 71 virtual void handleWheelEventPhase(PlatformWheelEventPhase) { } 72#endif 73 74 void setCurrentPosition(const FloatPoint&); 75 FloatPoint currentPosition() const; 76 77 virtual void cancelAnimations() { } 78 virtual void serviceScrollAnimations() { } 79 80 virtual void contentAreaWillPaint() const { } 81 virtual void mouseEnteredContentArea() const { } 82 virtual void mouseExitedContentArea() const { } 83 virtual void mouseMovedInContentArea() const { } 84 virtual void mouseEnteredScrollbar(Scrollbar*) const { } 85 virtual void mouseExitedScrollbar(Scrollbar*) const { } 86 virtual void willStartLiveResize() { } 87 virtual void contentsResized() const { } 88 virtual void willEndLiveResize() { } 89 virtual void contentAreaDidShow() const { } 90 virtual void contentAreaDidHide() const { } 91 92 virtual void lockOverlayScrollbarStateToHidden(bool) { } 93 virtual bool scrollbarsCanBeActive() const { return true; } 94 95 virtual void didAddVerticalScrollbar(Scrollbar*) { } 96 virtual void willRemoveVerticalScrollbar(Scrollbar*) { } 97 virtual void didAddHorizontalScrollbar(Scrollbar*) { } 98 virtual void willRemoveHorizontalScrollbar(Scrollbar*) { } 99 100 virtual void verticalScrollbarLayerDidChange() { } 101 virtual void horizontalScrollbarLayerDidChange() { } 102 103 virtual bool shouldScrollbarParticipateInHitTesting(Scrollbar*) { return true; } 104 105 virtual void notifyContentAreaScrolled(const FloatSize& delta) { UNUSED_PARAM(delta); } 106 107 virtual bool isRubberBandInProgress() const { return false; } 108 109protected: 110 explicit ScrollAnimator(ScrollableArea*); 111 112 virtual void notifyPositionChanged(const FloatSize& delta); 113 114 ScrollableArea* m_scrollableArea; 115 float m_currentPosX; // We avoid using a FloatPoint in order to reduce 116 float m_currentPosY; // subclass code complexity. 117}; 118 119} // namespace WebCore 120 121#endif // ScrollAnimator_h 122