1/*
2 * Copyright (C) 2007 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 LayoutState_h
27#define LayoutState_h
28
29#include "core/rendering/ColumnInfo.h"
30#include "platform/geometry/LayoutRect.h"
31#include "wtf/HashMap.h"
32#include "wtf/Noncopyable.h"
33
34namespace blink {
35
36class ForceHorriblySlowRectMapping;
37class RenderBox;
38class RenderObject;
39class RenderInline;
40class RenderView;
41
42class LayoutState {
43    WTF_MAKE_NONCOPYABLE(LayoutState);
44public:
45    // Constructor for root LayoutState created by RenderView
46    LayoutState(LayoutUnit pageLogicalHeight, bool pageLogicalHeightChanged, RenderView&);
47    // Constructor for sub-tree Layout and RenderTableSections
48    explicit LayoutState(RenderObject& root);
49
50    LayoutState(RenderBox&, const LayoutSize& offset, LayoutUnit pageLogicalHeight = 0, bool pageHeightLogicalChanged = false, ColumnInfo* = 0, bool containingBlockLogicalWidthChanged = false);
51    LayoutState(RenderInline&);
52
53    ~LayoutState();
54
55    void clearPaginationInformation();
56    bool isPaginatingColumns() const { return m_columnInfo; }
57    bool isPaginated() const { return m_isPaginated; }
58
59    // The page logical offset is the object's offset from the top of the page in the page progression
60    // direction (so an x-offset in vertical text and a y-offset for horizontal text).
61    LayoutUnit pageLogicalOffset(const RenderBox&, const LayoutUnit& childLogicalOffset) const;
62
63    void addForcedColumnBreak(const RenderBox&, const LayoutUnit& childLogicalOffset);
64
65    void setColumnInfo(ColumnInfo* columnInfo) { m_columnInfo = columnInfo; }
66
67    const LayoutSize& layoutOffset() const { return m_layoutOffset; }
68    const LayoutSize& pageOffset() const { return m_pageOffset; }
69    LayoutUnit pageLogicalHeight() const { return m_pageLogicalHeight; }
70    bool pageLogicalHeightChanged() const { return m_pageLogicalHeightChanged; }
71    bool containingBlockLogicalWidthChanged() const { return m_containingBlockLogicalWidthChanged; }
72
73    LayoutState* next() const { return m_next; }
74
75    bool needsBlockDirectionLocationSetBeforeLayout() const { return m_isPaginated && m_pageLogicalHeight; }
76
77    ColumnInfo* columnInfo() const { return m_columnInfo; }
78
79    RenderObject& renderer() const { return m_renderer; }
80
81private:
82    friend class ForceHorriblySlowRectMapping;
83
84    // Do not add anything apart from bitfields until after m_columnInfo. See https://bugs.webkit.org/show_bug.cgi?id=100173
85    bool m_isPaginated : 1;
86    // If our page height has changed, this will force all blocks to relayout.
87    bool m_pageLogicalHeightChanged : 1;
88    bool m_containingBlockLogicalWidthChanged : 1;
89
90    // If the enclosing pagination model is a column model, then this will store column information for easy retrieval/manipulation.
91    ColumnInfo* m_columnInfo;
92    LayoutState* m_next;
93
94    // x/y offset from container. Does not include relative positioning or scroll offsets.
95    LayoutSize m_layoutOffset;
96
97    // The current page height for the pagination model that encloses us.
98    LayoutUnit m_pageLogicalHeight;
99    // The offset of the start of the first page in the nearest enclosing pagination model.
100    LayoutSize m_pageOffset;
101
102    RenderObject& m_renderer;
103};
104
105} // namespace blink
106
107#endif // LayoutState_h
108