xref: /external/webkit/Source/WebCore/platform/ScrollAnimator.h

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#ifndef ScrollAnimator_h
#define ScrollAnimator_h

#include "ScrollTypes.h"
#include <wtf/Forward.h>

namespace WebCore {

class FloatPoint;
class PlatformWheelEvent;
class ScrollableArea;
class Scrollbar;

#if ENABLE(GESTURE_EVENTS)
class PlatformGestureEvent;
#endif

class ScrollAnimator {
public:
    static PassOwnPtr<ScrollAnimator> create(ScrollableArea*);

    virtual ~ScrollAnimator();

    // Computes a scroll destination for the given parameters.  Returns false if
    // already at the destination.  Otherwise, starts scrolling towards the
    // destination and returns true.  Scrolling may be immediate or animated.
    // The base class implementation always scrolls immediately, never animates.
    virtual bool scroll(ScrollbarOrientation, ScrollGranularity, float step, float multiplier);

    virtual void scrollToOffsetWithoutAnimation(const FloatPoint&);

    ScrollableArea* scrollableArea() const { return m_scrollableArea; }

    virtual void handleWheelEvent(PlatformWheelEvent&);
#if ENABLE(GESTURE_EVENTS)
    virtual void handleGestureEvent(const PlatformGestureEvent&);
#endif

    FloatPoint currentPosition() const;

    virtual void cancelAnimations() { }

    virtual void contentAreaWillPaint() const { }
    virtual void mouseEnteredContentArea() const { }
    virtual void mouseExitedContentArea() const { }
    virtual void mouseMovedInContentArea() const { }
    virtual void willStartLiveResize() { }
    virtual void contentsResized() const { }
    virtual void willEndLiveResize() { }
    virtual void contentAreaDidShow() const { }
    virtual void contentAreaDidHide() const { }

    virtual void didAddVerticalScrollbar(Scrollbar*) { }
    virtual void willRemoveVerticalScrollbar(Scrollbar*) { }
    virtual void didAddHorizontalScrollbar(Scrollbar*) { }
    virtual void willRemoveHorizontalScrollbar(Scrollbar*) { }

protected:
    ScrollAnimator(ScrollableArea*);

    virtual void notityPositionChanged();

    ScrollableArea* m_scrollableArea;
    float m_currentPosX; // We avoid using a FloatPoint in order to reduce
    float m_currentPosY; // subclass code complexity.
};

} // namespace WebCore

#endif // ScrollAnimator_h