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 RenderScrollbarPart_h
27#define RenderScrollbarPart_h
28
29#include "core/rendering/RenderBlock.h"
30#include "platform/scroll/ScrollTypes.h"
31
32namespace blink {
33
34class RenderScrollbar;
35
36class RenderScrollbarPart FINAL : public RenderBlock {
37public:
38    static RenderScrollbarPart* createAnonymous(Document*, RenderScrollbar* = 0, ScrollbarPart = NoPart);
39
40    virtual ~RenderScrollbarPart();
41
42    virtual const char* renderName() const OVERRIDE { return "RenderScrollbarPart"; }
43
44    virtual LayerType layerTypeRequired() const OVERRIDE { return NoLayer; }
45
46    virtual void layout() OVERRIDE;
47
48    void paintIntoRect(GraphicsContext*, const LayoutPoint&, const LayoutRect&);
49
50    // Scrollbar parts needs to be rendered at device pixel boundaries.
51    virtual LayoutUnit marginTop() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.top())); return m_marginBox.top(); }
52    virtual LayoutUnit marginBottom() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.bottom())); return m_marginBox.bottom(); }
53    virtual LayoutUnit marginLeft() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.left())); return m_marginBox.left(); }
54    virtual LayoutUnit marginRight() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.right())); return m_marginBox.right(); }
55
56    virtual bool isRenderScrollbarPart() const OVERRIDE { return true; }
57    RenderObject* rendererOwningScrollbar() const;
58
59protected:
60    virtual void styleWillChange(StyleDifference, const RenderStyle& newStyle) OVERRIDE;
61    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
62    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) OVERRIDE;
63
64private:
65    RenderScrollbarPart(RenderScrollbar*, ScrollbarPart);
66
67    virtual void computePreferredLogicalWidths() OVERRIDE;
68
69    // Have all padding getters return 0. The important point here is to avoid resolving percents
70    // against the containing block, since scroll bar corners don't always have one (so it would
71    // crash). Scroll bar corners are not actually laid out, and they don't have child content, so
72    // what we return here doesn't really matter.
73    virtual LayoutUnit paddingTop() const OVERRIDE { return LayoutUnit(); }
74    virtual LayoutUnit paddingBottom() const OVERRIDE { return LayoutUnit(); }
75    virtual LayoutUnit paddingLeft() const OVERRIDE { return LayoutUnit(); }
76    virtual LayoutUnit paddingRight() const OVERRIDE { return LayoutUnit(); }
77    virtual LayoutUnit paddingBefore() const OVERRIDE { return LayoutUnit(); }
78    virtual LayoutUnit paddingAfter() const OVERRIDE { return LayoutUnit(); }
79    virtual LayoutUnit paddingStart() const OVERRIDE { return LayoutUnit(); }
80    virtual LayoutUnit paddingEnd() const OVERRIDE { return LayoutUnit(); }
81
82    void layoutHorizontalPart();
83    void layoutVerticalPart();
84
85    void computeScrollbarWidth();
86    void computeScrollbarHeight();
87
88    RenderScrollbar* m_scrollbar;
89    ScrollbarPart m_part;
90};
91
92DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderScrollbarPart, isRenderScrollbarPart());
93
94} // namespace blink
95
96#endif // RenderScrollbarPart_h
97