1/*
2 * Copyright (C) 2004, 2006 Apple Computer, 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef Scrollbar_h
27#define Scrollbar_h
28
29#include "ScrollTypes.h"
30#include "Timer.h"
31#include "Widget.h"
32#include <wtf/MathExtras.h>
33#include <wtf/PassRefPtr.h>
34
35namespace WebCore {
36
37class GraphicsContext;
38class IntRect;
39class PlatformMouseEvent;
40class ScrollableArea;
41class ScrollbarTheme;
42
43class Scrollbar : public Widget {
44public:
45    // Must be implemented by platforms that can't simply use the Scrollbar base class.  Right now the only platform that is not using the base class is GTK.
46    static PassRefPtr<Scrollbar> createNativeScrollbar(ScrollableArea*, ScrollbarOrientation orientation, ScrollbarControlSize size);
47
48    virtual ~Scrollbar();
49
50    // Called by the ScrollableArea when the scroll offset changes.
51    void offsetDidChange();
52
53    static int pixelsPerLineStep() { return 40; }
54    static float minFractionToStepWhenPaging() { return 0.875f; }
55    static int maxOverlapBetweenPages();
56
57    void disconnectFromScrollableArea() { m_scrollableArea = 0; }
58    ScrollableArea* scrollableArea() const { return m_scrollableArea; }
59
60    virtual bool isCustomScrollbar() const { return false; }
61    ScrollbarOrientation orientation() const { return m_orientation; }
62
63    int value() const { return lroundf(m_currentPos); }
64    float currentPos() const { return m_currentPos; }
65    int pressedPos() const { return m_pressedPos; }
66    int visibleSize() const { return m_visibleSize; }
67    int totalSize() const { return m_totalSize; }
68    int maximum() const { return m_totalSize - m_visibleSize; }
69    ScrollbarControlSize controlSize() const { return m_controlSize; }
70
71    int lineStep() const { return m_lineStep; }
72    int pageStep() const { return m_pageStep; }
73    float pixelStep() const { return m_pixelStep; }
74
75    ScrollbarPart pressedPart() const { return m_pressedPart; }
76    ScrollbarPart hoveredPart() const { return m_hoveredPart; }
77    virtual void setHoveredPart(ScrollbarPart);
78    virtual void setPressedPart(ScrollbarPart);
79
80    void setSteps(int lineStep, int pageStep, int pixelsPerStep = 1);
81    void setProportion(int visibleSize, int totalSize);
82    void setPressedPos(int p) { m_pressedPos = p; }
83
84    virtual void paint(GraphicsContext*, const IntRect& damageRect);
85
86    bool enabled() const { return m_enabled; }
87    virtual void setEnabled(bool e);
88
89    virtual bool isOverlayScrollbar() const;
90
91    bool isWindowActive() const;
92
93    // These methods are used for platform scrollbars to give :hover feedback.  They will not get called
94    // when the mouse went down in a scrollbar, since it is assumed the scrollbar will start
95    // grabbing all events in that case anyway.
96    bool mouseMoved(const PlatformMouseEvent&);
97    bool mouseExited();
98
99    // Used by some platform scrollbars to know when they've been released from capture.
100    bool mouseUp();
101
102    bool mouseDown(const PlatformMouseEvent&);
103
104#if PLATFORM(QT)
105    // For platforms that wish to handle context menu events.
106    // FIXME: This is misplaced.  Normal hit testing should be used to populate a correct
107    // context menu.  There's no reason why the scrollbar should have to do it.
108    bool contextMenu(const PlatformMouseEvent& event);
109#endif
110
111    ScrollbarTheme* theme() const { return m_theme; }
112
113    virtual void setParent(ScrollView*);
114    virtual void setFrameRect(const IntRect&);
115
116    virtual void invalidateRect(const IntRect&);
117
118    bool suppressInvalidation() const { return m_suppressInvalidation; }
119    void setSuppressInvalidation(bool s) { m_suppressInvalidation = s; }
120
121    virtual void styleChanged() { }
122
123    virtual IntRect convertToContainingView(const IntRect&) const;
124    virtual IntRect convertFromContainingView(const IntRect&) const;
125
126    virtual IntPoint convertToContainingView(const IntPoint&) const;
127    virtual IntPoint convertFromContainingView(const IntPoint&) const;
128
129protected:
130    Scrollbar(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize, ScrollbarTheme* = 0);
131
132    void updateThumb();
133    virtual void updateThumbPosition();
134    virtual void updateThumbProportion();
135
136    void autoscrollTimerFired(Timer<Scrollbar>*);
137    void startTimerIfNeeded(double delay);
138    void stopTimerIfNeeded();
139    void autoscrollPressedPart(double delay);
140    ScrollDirection pressedPartScrollDirection();
141    ScrollGranularity pressedPartScrollGranularity();
142
143    void moveThumb(int pos);
144
145    ScrollableArea* m_scrollableArea;
146    ScrollbarOrientation m_orientation;
147    ScrollbarControlSize m_controlSize;
148    ScrollbarTheme* m_theme;
149
150    int m_visibleSize;
151    int m_totalSize;
152    float m_currentPos;
153    float m_dragOrigin;
154    int m_lineStep;
155    int m_pageStep;
156    float m_pixelStep;
157
158    ScrollbarPart m_hoveredPart;
159    ScrollbarPart m_pressedPart;
160    int m_pressedPos;
161
162    bool m_enabled;
163
164    Timer<Scrollbar> m_scrollTimer;
165    bool m_overlapsResizer;
166
167    bool m_suppressInvalidation;
168
169private:
170    virtual bool isScrollbar() const { return true; }
171    virtual AXObjectCache* axObjectCache() const;
172};
173
174} // namespace WebCore
175
176#endif // Scrollbar_h
177