1/*
2 * Copyright (C) 2012 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#pragma once
27
28#include "RenderFragmentedFlow.h"
29#include <wtf/HashMap.h>
30
31namespace WebCore {
32
33class RenderMultiColumnSet;
34class RenderMultiColumnSpannerPlaceholder;
35
36class RenderMultiColumnFlow final : public RenderFragmentedFlow {
37 WTF_MAKE_ISO_ALLOCATED(RenderMultiColumnFlow);
38public:
39 RenderMultiColumnFlow(Document&, RenderStyle&&);
40 ~RenderMultiColumnFlow();
41
42 RenderBlockFlow* multiColumnBlockFlow() const { return downcast<RenderBlockFlow>(parent()); }
43
44 RenderMultiColumnSet* firstMultiColumnSet() const;
45 RenderMultiColumnSet* lastMultiColumnSet() const;
46 RenderBox* firstColumnSetOrSpanner() const;
47 bool hasColumnSpanner() const { return !m_spannerMap->isEmpty(); }
48 static RenderBox* nextColumnSetOrSpannerSiblingOf(const RenderBox*);
49 static RenderBox* previousColumnSetOrSpannerSiblingOf(const RenderBox*);
50
51 RenderMultiColumnSpannerPlaceholder* findColumnSpannerPlaceholder(RenderBox* spanner) const { return m_spannerMap->get(spanner).get(); }
52
53 void layout() override;
54
55 unsigned columnCount() const { return m_columnCount; }
56 LayoutUnit columnWidth() const { return m_columnWidth; }
57 LayoutUnit columnHeightAvailable() const { return m_columnHeightAvailable; }
58 void setColumnHeightAvailable(LayoutUnit available) { m_columnHeightAvailable = available; }
59 bool inBalancingPass() const { return m_inBalancingPass; }
60 void setInBalancingPass(bool balancing) { m_inBalancingPass = balancing; }
61 bool needsHeightsRecalculation() const { return m_needsHeightsRecalculation; }
62 void setNeedsHeightsRecalculation(bool recalculate) { m_needsHeightsRecalculation = recalculate; }
63
64 bool shouldRelayoutForPagination() const { return !m_inBalancingPass && m_needsHeightsRecalculation; }
65
66 void setColumnCountAndWidth(unsigned count, LayoutUnit width)
67 {
68 m_columnCount = count;
69 m_columnWidth = width;
70 }
71
72 bool progressionIsInline() const { return m_progressionIsInline; }
73 void setProgressionIsInline(bool progressionIsInline) { m_progressionIsInline = progressionIsInline; }
74
75 bool progressionIsReversed() const { return m_progressionIsReversed; }
76 void setProgressionIsReversed(bool reversed) { m_progressionIsReversed = reversed; }
77
78 RenderFragmentContainer* mapFromFlowToFragment(TransformState&) const override;
79
80 // This method takes a logical offset and returns a physical translation that can be applied to map
81 // a physical point (corresponding to the logical offset) into the fragment's physical coordinate space.
82 LayoutSize physicalTranslationOffsetFromFlowToFragment(const RenderFragmentContainer*, const LayoutUnit) const;
83
84 // The point is physical, and the result is a physical location within the fragment.
85 RenderFragmentContainer* physicalTranslationFromFlowToFragment(LayoutPoint&) const;
86
87 // This method is the inverse of the previous method and goes from fragment to flow.
88 LayoutSize physicalTranslationFromFragmentToFlow(const RenderMultiColumnSet*, const LayoutPoint&) const;
89
90 bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
91
92 void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const override;
93 LayoutSize offsetFromContainer(RenderElement&, const LayoutPoint&, bool* offsetDependsOnPoint = nullptr) const override;
94
95 // FIXME: Eventually as column and fragment flow threads start nesting, this will end up changing.
96 bool shouldCheckColumnBreaks() const override;
97
98 typedef HashMap<RenderBox*, WeakPtr<RenderMultiColumnSpannerPlaceholder>> SpannerMap;
99 SpannerMap& spannerMap() { return *m_spannerMap; }
100
101private:
102 bool isRenderMultiColumnFlow() const override { return true; }
103 const char* renderName() const override;
104 void addFragmentToThread(RenderFragmentContainer*) override;
105 void willBeRemovedFromTree() override;
106 void fragmentedFlowDescendantBoxLaidOut(RenderBox*) override;
107 LogicalExtentComputedValues computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop) const override;
108 LayoutUnit initialLogicalWidth() const override;
109 void setPageBreak(const RenderBlock*, LayoutUnit offset, LayoutUnit spaceShortage) override;
110 void updateMinimumPageHeight(const RenderBlock*, LayoutUnit offset, LayoutUnit minHeight) override;
111 RenderFragmentContainer* fragmentAtBlockOffset(const RenderBox*, LayoutUnit, bool extendLastFragment = false) const override;
112 void setFragmentRangeForBox(const RenderBox&, RenderFragmentContainer*, RenderFragmentContainer*) override;
113 bool addForcedFragmentBreak(const RenderBlock*, LayoutUnit, RenderBox* breakChild, bool isBefore, LayoutUnit* offsetBreakAdjustment = 0) override;
114 bool isPageLogicalHeightKnown() const override;
115
116private:
117 std::unique_ptr<SpannerMap> m_spannerMap;
118
119 // The last set we worked on. It's not to be used as the "current set". The concept of a
120 // "current set" is difficult, since layout may jump back and forth in the tree, due to wrong
121 // top location estimates (due to e.g. margin collapsing), and possibly for other reasons.
122 RenderMultiColumnSet* m_lastSetWorkedOn;
123
124 unsigned m_columnCount; // The default column count/width that are based off our containing block width. These values represent only the default,
125 LayoutUnit m_columnWidth; // A multi-column block that is split across variable width pages or fragments will have different column counts and widths in each. These values will be cached (eventually) for multi-column blocks.
126
127 LayoutUnit m_columnHeightAvailable; // Total height available to columns, or 0 if auto.
128 bool m_inLayout; // Set while we're laying out the flow thread, during which colum set heights are unknown.
129 bool m_inBalancingPass; // Guard to avoid re-entering column balancing.
130 bool m_needsHeightsRecalculation;
131
132 bool m_progressionIsInline;
133 bool m_progressionIsReversed;
134};
135
136} // namespace WebCore
137
138SPECIALIZE_TYPE_TRAITS_RENDER_OBJECT(RenderMultiColumnFlow, isRenderMultiColumnFlow())
139