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 "platform/geometry/LayoutRect.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 { 41 WTF_MAKE_NONCOPYABLE(RenderOverflow); WTF_MAKE_FAST_ALLOCATED; 42 public: 43 RenderOverflow(const LayoutRect& layoutRect, const LayoutRect& visualRect) 44 : m_layoutOverflow(layoutRect) 45 , m_visualOverflow(visualRect) 46 { 47 } 48 49 const LayoutRect layoutOverflowRect() const { return m_layoutOverflow; } 50 const LayoutRect visualOverflowRect() const { return m_visualOverflow; } 51 LayoutRect contentsVisualOverflowRect() const { return m_contentsVisualOverflow; } 52 53 void move(LayoutUnit dx, LayoutUnit dy); 54 55 void addLayoutOverflow(const LayoutRect&); 56 void addVisualOverflow(const LayoutRect&); 57 void addContentsVisualOverflow(const LayoutRect& rect) { m_contentsVisualOverflow.unite(rect); } 58 59 void setLayoutOverflow(const LayoutRect&); 60 void setVisualOverflow(const LayoutRect&); 61 62 LayoutUnit layoutClientAfterEdge() const { return m_layoutClientAfterEdge; } 63 void setLayoutClientAfterEdge(LayoutUnit clientAfterEdge) { m_layoutClientAfterEdge = clientAfterEdge; } 64 65 private: 66 LayoutRect m_layoutOverflow; 67 LayoutRect m_visualOverflow; 68 LayoutRect m_contentsVisualOverflow; 69 70 LayoutUnit m_layoutClientAfterEdge; 71 }; 72 73 inline void RenderOverflow::move(LayoutUnit dx, LayoutUnit dy) 74 { 75 m_layoutOverflow.move(dx, dy); 76 m_visualOverflow.move(dx, dy); 77 m_contentsVisualOverflow.move(dx, dy); 78 } 79 80 inline void RenderOverflow::addLayoutOverflow(const LayoutRect& rect) 81 { 82 LayoutUnit maxX = std::max(rect.maxX(), m_layoutOverflow.maxX()); 83 LayoutUnit maxY = std::max(rect.maxY(), m_layoutOverflow.maxY()); 84 LayoutUnit minX = std::min(rect.x(), m_layoutOverflow.x()); 85 LayoutUnit minY = std::min(rect.y(), m_layoutOverflow.y()); 86 // In case the width/height is larger than LayoutUnit can represent, fix the right/bottom edge and shift the top/left ones 87 m_layoutOverflow.setWidth(maxX - minX); 88 m_layoutOverflow.setHeight(maxY - minY); 89 m_layoutOverflow.setX(maxX - m_layoutOverflow.width()); 90 m_layoutOverflow.setY(maxY - m_layoutOverflow.height()); 91 } 92 93 inline void RenderOverflow::addVisualOverflow(const LayoutRect& rect) 94 { 95 LayoutUnit maxX = std::max(rect.maxX(), m_visualOverflow.maxX()); 96 LayoutUnit maxY = std::max(rect.maxY(), m_visualOverflow.maxY()); 97 m_visualOverflow.setX(std::min(rect.x(), m_visualOverflow.x())); 98 m_visualOverflow.setY(std::min(rect.y(), m_visualOverflow.y())); 99 m_visualOverflow.setWidth(maxX - m_visualOverflow.x()); 100 m_visualOverflow.setHeight(maxY - m_visualOverflow.y()); 101 } 102 103 inline void RenderOverflow::setLayoutOverflow(const LayoutRect& rect) 104 { 105 m_layoutOverflow = rect; 106 } 107 108 inline void RenderOverflow::setVisualOverflow(const LayoutRect& rect) 109 { 110 m_visualOverflow = rect; 111 } 112 113 } // namespace WebCore 114 115 #endif // RenderOverflow_h 116