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 "ScrollTypes.h"
35#include <wtf/Forward.h>
36
37namespace WebCore {
38
39class FloatPoint;
40class PlatformWheelEvent;
41class ScrollableArea;
42class Scrollbar;
43
44#if ENABLE(GESTURE_EVENTS)
45class PlatformGestureEvent;
46#endif
47
48class ScrollAnimator {
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 void handleWheelEvent(PlatformWheelEvent&);
65#if ENABLE(GESTURE_EVENTS)
66    virtual void handleGestureEvent(const PlatformGestureEvent&);
67#endif
68
69    FloatPoint currentPosition() const;
70
71    virtual void cancelAnimations() { }
72
73    virtual void contentAreaWillPaint() const { }
74    virtual void mouseEnteredContentArea() const { }
75    virtual void mouseExitedContentArea() const { }
76    virtual void mouseMovedInContentArea() const { }
77    virtual void willStartLiveResize() { }
78    virtual void contentsResized() const { }
79    virtual void willEndLiveResize() { }
80    virtual void contentAreaDidShow() const { }
81    virtual void contentAreaDidHide() const { }
82
83    virtual void didAddVerticalScrollbar(Scrollbar*) { }
84    virtual void willRemoveVerticalScrollbar(Scrollbar*) { }
85    virtual void didAddHorizontalScrollbar(Scrollbar*) { }
86    virtual void willRemoveHorizontalScrollbar(Scrollbar*) { }
87
88protected:
89    ScrollAnimator(ScrollableArea*);
90
91    virtual void notityPositionChanged();
92
93    ScrollableArea* m_scrollableArea;
94    float m_currentPosX; // We avoid using a FloatPoint in order to reduce
95    float m_currentPosY; // subclass code complexity.
96};
97
98} // namespace WebCore
99
100#endif // ScrollAnimator_h
101