1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/*
* Copyright (C) 2012 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "RenderMultiColumnBlock.h"
#include "RenderMultiColumnFlowThread.h"
#include "RenderMultiColumnSet.h"
using namespace std;
namespace WebCore {
RenderMultiColumnBlock::RenderMultiColumnBlock(Node* node)
: RenderBlock(node)
, m_flowThread(0)
, m_columnCount(1)
, m_columnWidth(ZERO_LAYOUT_UNIT)
, m_columnHeight(ZERO_LAYOUT_UNIT)
{
}
void RenderMultiColumnBlock::computeColumnCountAndWidth()
{
// Calculate our column width and column count.
// FIXME: Can overflow on fast/block/float/float-not-removed-from-next-sibling4.html, see https://bugs.webkit.org/show_bug.cgi?id=68744
m_columnCount = 1;
m_columnWidth = contentLogicalWidth();
ASSERT(!style()->hasAutoColumnCount() || !style()->hasAutoColumnWidth());
LayoutUnit availWidth = m_columnWidth;
LayoutUnit colGap = columnGap();
LayoutUnit colWidth = max<LayoutUnit>(1, LayoutUnit(style()->columnWidth()));
int colCount = max<int>(1, style()->columnCount());
if (style()->hasAutoColumnWidth() && !style()->hasAutoColumnCount()) {
m_columnCount = colCount;
m_columnWidth = max<LayoutUnit>(0, (availWidth - ((m_columnCount - 1) * colGap)) / m_columnCount);
} else if (!style()->hasAutoColumnWidth() && style()->hasAutoColumnCount()) {
m_columnCount = max<LayoutUnit>(1, (availWidth + colGap) / (colWidth + colGap));
m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
} else {
m_columnCount = max<LayoutUnit>(min<LayoutUnit>(colCount, (availWidth + colGap) / (colWidth + colGap)), 1);
m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
}
}
bool RenderMultiColumnBlock::recomputeLogicalWidth()
{
bool relayoutChildren = RenderBlock::recomputeLogicalWidth();
LayoutUnit oldColumnWidth = m_columnWidth;
computeColumnCountAndWidth();
if (m_columnWidth != oldColumnWidth)
relayoutChildren = true;
return relayoutChildren;
}
void RenderMultiColumnBlock::checkForPaginationLogicalHeightChange(LayoutUnit& pageLogicalHeight, bool& pageLogicalHeightChanged, bool& hasSpecifiedPageLogicalHeight)
{
// We need to go ahead and set our explicit page height if one exists, so that we can
// avoid doing multiple layout passes.
computeLogicalHeight();
LayoutUnit newContentLogicalHeight = contentLogicalHeight();
if (newContentLogicalHeight > ZERO_LAYOUT_UNIT) {
pageLogicalHeight = newContentLogicalHeight;
hasSpecifiedPageLogicalHeight = true;
}
setLogicalHeight(ZERO_LAYOUT_UNIT);
if (columnHeight() != pageLogicalHeight && everHadLayout()) {
setColumnHeight(pageLogicalHeight);
pageLogicalHeightChanged = true;
}
// Set up our column sets.
ensureColumnSets();
}
bool RenderMultiColumnBlock::relayoutForPagination(bool, LayoutUnit, LayoutStateMaintainer&)
{
// FIXME: Implement.
return false;
}
void RenderMultiColumnBlock::addChild(RenderObject* newChild, RenderObject* beforeChild)
{
if (!m_flowThread) {
m_flowThread = new (renderArena()) RenderMultiColumnFlowThread(document());
m_flowThread->setStyle(RenderStyle::createAnonymousStyleWithDisplay(style(), BLOCK));
RenderBlock::addChild(m_flowThread); // Always put the flow thread at the end.
}
// Column sets are siblings of the flow thread. All children designed to be in the columns, however, are part
// of the flow thread itself.
if (newChild->isRenderMultiColumnSet())
RenderBlock::addChild(newChild, beforeChild);
else
m_flowThread->addChild(newChild, beforeChild);
}
void RenderMultiColumnBlock::ensureColumnSets()
{
// This function ensures we have the correct column set information before we get into layout.
// For a simple multi-column layout in continuous media, only one column set child is required.
// Once a column is nested inside an enclosing pagination context, the number of column sets
// required becomes 2n-1, where n is the total number of nested pagination contexts. For example:
//
// Column layout with no enclosing pagination model = 2 * 1 - 1 = 1 column set.
// Columns inside pages = 2 * 2 - 1 = 3 column sets (bottom of first page, all the subsequent pages, then the last page).
// Columns inside columns inside pages = 2 * 3 - 1 = 5 column sets.
//
// In addition, column spans will force a column set to "split" into before/after sets around the spanning region.
//
// Finally, we will need to deal with columns inside regions. If regions have variable widths, then there will need
// to be unique column sets created inside any region whose width is different from its surrounding regions. This is
// actually pretty similar to the spanning case, in that we break up the column sets whenever the width varies.
//
// FIXME: For now just make one column set. This matches the old multi-column code.
// Right now our goal is just feature parity with the old multi-column code so that we can switch over to the
// new code as soon as possible.
if (flowThread() && !firstChild()->isRenderMultiColumnSet()) {
RenderMultiColumnSet* columnSet = new (renderArena()) RenderMultiColumnSet(document(), flowThread());
columnSet->setStyle(RenderStyle::createAnonymousStyleWithDisplay(style(), BLOCK));
RenderBlock::addChild(columnSet, firstChild());
}
}
const char* RenderMultiColumnBlock::renderName() const
{
if (isFloating())
return "RenderMultiColumnBlock (floating)";
if (isOutOfFlowPositioned())
return "RenderMultiColumnBlock (positioned)";
if (isAnonymousBlock())
return "RenderMultiColumnBlock (anonymous)";
if (isAnonymous())
return "RenderMultiColumnBlock (generated)";
if (isRelPositioned())
return "RenderMultiColumnBlock (relative positioned)";
return "RenderMultiColumnBlock";
}
}
|
