ScrollbarTheme.h revision 635860845790a19bf50bbc51ba8fb66a96dde068 
1/*
2 * Copyright (C) 2008 Apple 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 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 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 ScrollbarTheme_h
27#define ScrollbarTheme_h
28
29#include "GraphicsContext.h"
30#include "IntRect.h"
31#include "ScrollTypes.h"
32
33namespace WebCore {
34
35class PlatformMouseEvent;
36class Scrollbar;
37class ScrollView;
38
39class ScrollbarTheme {
40public:
41    virtual ~ScrollbarTheme() {};
42
43    virtual bool paint(Scrollbar*, GraphicsContext*, const IntRect& /*damageRect*/) { return false; }
44    virtual ScrollbarPart hitTest(Scrollbar*, const PlatformMouseEvent&) { return NoPart; }
45
46    virtual int scrollbarThickness(ScrollbarControlSize = RegularScrollbar) { return 0; }
47
48    virtual ScrollbarButtonsPlacement buttonsPlacement() const { return ScrollbarButtonsSingle; }
49
50    virtual bool supportsControlTints() const { return false; }
51
52    virtual void themeChanged() {}
53
54    virtual bool invalidateOnMouseEnterExit() { return false; }
55
56    void invalidateParts(Scrollbar* scrollbar, ScrollbarControlPartMask mask)
57    {
58        if (mask & BackButtonStartPart)
59            invalidatePart(scrollbar, BackButtonStartPart);
60        if (mask & ForwardButtonStartPart)
61            invalidatePart(scrollbar, ForwardButtonStartPart);
62        if (mask & BackTrackPart)
63            invalidatePart(scrollbar, BackTrackPart);
64        if (mask & ThumbPart)
65            invalidatePart(scrollbar, ThumbPart);
66        if (mask & ForwardTrackPart)
67            invalidatePart(scrollbar, ForwardTrackPart);
68        if (mask & BackButtonEndPart)
69            invalidatePart(scrollbar, BackButtonEndPart);
70        if (mask & ForwardButtonEndPart)
71            invalidatePart(scrollbar, ForwardButtonEndPart);
72    }
73
74    virtual void invalidatePart(Scrollbar*, ScrollbarPart) {}
75
76    virtual void paintScrollCorner(ScrollView*, GraphicsContext* context, const IntRect& cornerRect) { context->fillRect(cornerRect, Color::white); }
77
78    virtual bool shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent&) { return false; }
79    virtual int thumbPosition(Scrollbar*) { return 0; } // The position of the thumb relative to the track.
80    virtual int thumbLength(Scrollbar*) { return 0; } // The length of the thumb along the axis of the scrollbar.
81    virtual int trackPosition(Scrollbar*) { return 0; } // The position of the track relative to the scrollbar.
82    virtual int trackLength(Scrollbar*) { return 0; } // The length of the track along the axis of the scrollbar.
83
84    virtual double initialAutoscrollTimerDelay() { return 0.25; }
85    virtual double autoscrollTimerDelay() { return 0.05; }
86
87    virtual void registerScrollbar(Scrollbar*) {}
88    virtual void unregisterScrollbar(Scrollbar*) {}
89
90    static ScrollbarTheme* nativeTheme(); // Must be implemented to return the correct theme subclass.
91};
92
93}
94#endif
95