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31 #ifndef ScrollAnimator_h
32 #define ScrollAnimator_h
34 #include "platform/PlatformExport.h"
35 #include "platform/PlatformWheelEvent.h"
36 #include "platform/geometry/FloatSize.h"
37 #include "platform/scroll/ScrollTypes.h"
38 #include "wtf/FastAllocBase.h"
39 #include "wtf/Forward.h"
40 #include "wtf/Noncopyable.h"
48 class PLATFORM_EXPORT ScrollAnimator {
49 WTF_MAKE_FAST_ALLOCATED; WTF_MAKE_NONCOPYABLE(ScrollAnimator);
51 static PassOwnPtr<ScrollAnimator> create(ScrollableArea*);
53 virtual ~ScrollAnimator();
55 // Computes a scroll destination for the given parameters. Returns false if
56 // already at the destination. Otherwise, starts scrolling towards the
57 // destination and returns true. Scrolling may be immediate or animated.
58 // The base class implementation always scrolls immediately, never animates.
59 virtual bool scroll(ScrollbarOrientation, ScrollGranularity, float step, float delta);
61 virtual void scrollToOffsetWithoutAnimation(const FloatPoint&);
63 ScrollableArea* scrollableArea() const { return m_scrollableArea; }
65 virtual void setIsActive() { }
67 virtual bool handleWheelEvent(const PlatformWheelEvent&);
70 virtual void handleWheelEventPhase(PlatformWheelEventPhase) { }
73 void setCurrentPosition(const FloatPoint&);
74 FloatPoint currentPosition() const;
76 virtual void cancelAnimations() { }
77 virtual void serviceScrollAnimations() { }
79 virtual void contentAreaWillPaint() const { }
80 virtual void mouseEnteredContentArea() const { }
81 virtual void mouseExitedContentArea() const { }
82 virtual void mouseMovedInContentArea() const { }
83 virtual void mouseEnteredScrollbar(Scrollbar*) const { }
84 virtual void mouseExitedScrollbar(Scrollbar*) const { }
85 virtual void willStartLiveResize() { }
86 virtual void contentsResized() const { }
87 virtual void willEndLiveResize() { }
88 virtual void contentAreaDidShow() const { }
89 virtual void contentAreaDidHide() const { }
91 virtual void finishCurrentScrollAnimations() { }
93 virtual void didAddVerticalScrollbar(Scrollbar*) { }
94 virtual void willRemoveVerticalScrollbar(Scrollbar*) { }
95 virtual void didAddHorizontalScrollbar(Scrollbar*) { }
96 virtual void willRemoveHorizontalScrollbar(Scrollbar*) { }
98 virtual bool shouldScrollbarParticipateInHitTesting(Scrollbar*) { return true; }
100 virtual void notifyContentAreaScrolled(const FloatSize&) { }
102 virtual bool isRubberBandInProgress() const { return false; }
105 explicit ScrollAnimator(ScrollableArea*);
107 virtual void notifyPositionChanged();
109 ScrollableArea* m_scrollableArea;
110 float m_currentPosX; // We avoid using a FloatPoint in order to reduce
111 float m_currentPosY; // subclass code complexity.
114 float clampScrollPosition(ScrollbarOrientation, float);
119 #endif // ScrollAnimator_h