1 /*
2 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21 #ifndef RenderOverflow_h
22 #define RenderOverflow_h
23
24 #include "IntRect.h"
25
26 namespace WebCore
27 {
28 // RenderOverflow is a class for tracking content that spills out of a box. This class is used by RenderBox and
29 // InlineFlowBox.
30 //
31 // There are two types of overflow: layout overflow (which is expected to be reachable via scrolling mechanisms) and
32 // visual overflow (which is not expected to be reachable via scrolling mechanisms).
33 //
34 // Layout overflow examples include other boxes that spill out of our box, For example, in the inline case a tall image
35 // could spill out of a line box.
36
37 // Examples of visual overflow are shadows, text stroke (and eventually outline and border-image).
38
39 // This object is allocated only when some of these fields have non-default values in the owning box.
40 class RenderOverflow : public Noncopyable {
41 public:
42 RenderOverflow(const IntRect& defaultRect = IntRect())
43 : m_topLayoutOverflow(defaultRect.y())
44 , m_bottomLayoutOverflow(defaultRect.bottom())
45 , m_leftLayoutOverflow(defaultRect.x())
46 , m_rightLayoutOverflow(defaultRect.right())
47 , m_topVisualOverflow(defaultRect.y())
48 , m_bottomVisualOverflow(defaultRect.bottom())
49 , m_leftVisualOverflow(defaultRect.x())
50 , m_rightVisualOverflow(defaultRect.right())
51 {
52 }
53
topLayoutOverflow()54 int topLayoutOverflow() const { return m_topLayoutOverflow; }
bottomLayoutOverflow()55 int bottomLayoutOverflow() const { return m_bottomLayoutOverflow; }
leftLayoutOverflow()56 int leftLayoutOverflow() const { return m_leftLayoutOverflow; }
rightLayoutOverflow()57 int rightLayoutOverflow() const { return m_rightLayoutOverflow; }
58 IntRect layoutOverflowRect() const;
59
topVisualOverflow()60 int topVisualOverflow() const { return m_topVisualOverflow; }
bottomVisualOverflow()61 int bottomVisualOverflow() const { return m_bottomVisualOverflow; }
leftVisualOverflow()62 int leftVisualOverflow() const { return m_leftVisualOverflow; }
rightVisualOverflow()63 int rightVisualOverflow() const { return m_rightVisualOverflow; }
64 IntRect visualOverflowRect() const;
65
66 IntRect visibleOverflowRect() const;
67
setTopLayoutOverflow(int overflow)68 void setTopLayoutOverflow(int overflow) { m_topLayoutOverflow = overflow; }
setBottomLayoutOverflow(int overflow)69 void setBottomLayoutOverflow(int overflow) { m_bottomLayoutOverflow = overflow; }
setLeftLayoutOverflow(int overflow)70 void setLeftLayoutOverflow(int overflow) { m_leftLayoutOverflow = overflow; }
setRightLayoutOverflow(int overflow)71 void setRightLayoutOverflow(int overflow) { m_rightLayoutOverflow = overflow; }
72
setTopVisualOverflow(int overflow)73 void setTopVisualOverflow(int overflow) { m_topVisualOverflow = overflow; }
setBottomVisualOverflow(int overflow)74 void setBottomVisualOverflow(int overflow) { m_bottomVisualOverflow = overflow; }
setLeftVisualOverflow(int overflow)75 void setLeftVisualOverflow(int overflow) { m_leftVisualOverflow = overflow; }
setRightVisualOverflow(int overflow)76 void setRightVisualOverflow(int overflow) { m_rightVisualOverflow = overflow; }
77
78 void move(int dx, int dy);
79
80 void addLayoutOverflow(const IntRect&);
81 void addVisualOverflow(const IntRect&);
82
83 void resetLayoutOverflow(const IntRect& defaultRect);
84
85 private:
86 int m_topLayoutOverflow;
87 int m_bottomLayoutOverflow;
88 int m_leftLayoutOverflow;
89 int m_rightLayoutOverflow;
90
91 int m_topVisualOverflow;
92 int m_bottomVisualOverflow;
93 int m_leftVisualOverflow;
94 int m_rightVisualOverflow;
95 };
96
layoutOverflowRect()97 inline IntRect RenderOverflow::layoutOverflowRect() const
98 {
99 return IntRect(m_leftLayoutOverflow, m_topLayoutOverflow, m_rightLayoutOverflow - m_leftLayoutOverflow, m_bottomLayoutOverflow - m_topLayoutOverflow);
100 }
101
visualOverflowRect()102 inline IntRect RenderOverflow::visualOverflowRect() const
103 {
104 return IntRect(m_leftVisualOverflow, m_topVisualOverflow, m_rightVisualOverflow - m_leftVisualOverflow, m_bottomVisualOverflow - m_topVisualOverflow);
105 }
106
visibleOverflowRect()107 inline IntRect RenderOverflow::visibleOverflowRect() const
108 {
109 IntRect combinedRect(layoutOverflowRect());
110 combinedRect.unite(visualOverflowRect());
111 return combinedRect;
112 }
113
move(int dx,int dy)114 inline void RenderOverflow::move(int dx, int dy)
115 {
116 m_topLayoutOverflow += dy;
117 m_bottomLayoutOverflow += dy;
118 m_leftLayoutOverflow += dx;
119 m_rightLayoutOverflow += dx;
120
121 m_topVisualOverflow += dy;
122 m_bottomVisualOverflow += dy;
123 m_leftVisualOverflow += dx;
124 m_rightVisualOverflow += dx;
125 }
126
addLayoutOverflow(const IntRect & rect)127 inline void RenderOverflow::addLayoutOverflow(const IntRect& rect)
128 {
129 m_topLayoutOverflow = std::min(rect.y(), m_topLayoutOverflow);
130 m_bottomLayoutOverflow = std::max(rect.bottom(), m_bottomLayoutOverflow);
131 m_leftLayoutOverflow = std::min(rect.x(), m_leftLayoutOverflow);
132 m_rightLayoutOverflow = std::max(rect.right(), m_rightLayoutOverflow);
133 }
134
addVisualOverflow(const IntRect & rect)135 inline void RenderOverflow::addVisualOverflow(const IntRect& rect)
136 {
137 m_topVisualOverflow = std::min(rect.y(), m_topVisualOverflow);
138 m_bottomVisualOverflow = std::max(rect.bottom(), m_bottomVisualOverflow);
139 m_leftVisualOverflow = std::min(rect.x(), m_leftVisualOverflow);
140 m_rightVisualOverflow = std::max(rect.right(), m_rightVisualOverflow);
141 }
142
resetLayoutOverflow(const IntRect & rect)143 inline void RenderOverflow::resetLayoutOverflow(const IntRect& rect)
144 {
145 m_topLayoutOverflow = rect.y();
146 m_bottomLayoutOverflow = rect.bottom();
147 m_leftLayoutOverflow = rect.x();
148 m_rightLayoutOverflow = rect.right();
149 }
150
151 } // namespace WebCore
152
153 #endif // RenderOverflow_h
154