1/*
2 * Copyright (C) 2018 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. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
29
30#include <wtf/HashMap.h>
31#include <wtf/HashSet.h>
32#include <wtf/IsoMalloc.h>
33#include <wtf/OptionSet.h>
34
35namespace WebCore {
36
37#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
38class RenderView;
39#endif
40
41namespace Display {
42class Box;
43}
44
45namespace Layout {
46
47enum class StyleDiff;
48class Box;
49class Container;
50class FormattingContext;
51class FormattingState;
52
53// LayoutState is the entry point for layout. It takes the initial containing block which acts as the root of the layout context.
54// LayoutState::layout() generates the display tree for the root container's subtree (it does not run layout on the root though).
55// Note, while the initial containing block is entry point for the initial layout, it does not necessarily need to be the entry point of any
56// subsequent layouts (subtree layout). A non-initial, subtree layout could be initiated on multiple formatting contexts.
57// Each formatting context has an entry point for layout, which potenitally means multiple entry points per layout frame.
58// LayoutState also holds the formatting states. They cache formatting context specific data to enable performant incremental layouts.
59class LayoutState {
60 WTF_MAKE_ISO_ALLOCATED(LayoutState);
61public:
62 LayoutState(const Container& initialContainingBlock);
63
64 void updateLayout();
65 void styleChanged(const Box&, StyleDiff);
66 void setInQuirksMode(bool inQuirksMode) { m_inQuirksMode = inQuirksMode; }
67
68 enum class UpdateType {
69 Overflow = 1 << 0,
70 Position = 1 << 1,
71 Size = 1 << 2,
72 All = Overflow | Position | Size
73 };
74 void markNeedsUpdate(const Box&, OptionSet<UpdateType>);
75 bool needsUpdate(const Box&) const;
76
77 FormattingState& formattingStateForBox(const Box&) const;
78 FormattingState& establishedFormattingState(const Box& formattingRoot) const;
79 bool hasFormattingState(const Box& formattingRoot) const { return m_formattingStates.contains(&formattingRoot); }
80 FormattingState& createFormattingStateForFormattingRootIfNeeded(const Box& formattingRoot);
81
82 std::unique_ptr<FormattingContext> createFormattingContext(const Box& formattingContextRoot);
83#ifndef NDEBUG
84 void registerFormattingContext(const FormattingContext&);
85 void deregisterFormattingContext(const FormattingContext& formattingContext) { m_formattingContextList.remove(&formattingContext); }
86#endif
87
88 Display::Box& displayBoxForLayoutBox(const Box& layoutBox) const;
89 bool hasDisplayBox(const Box& layoutBox) const { return m_layoutToDisplayBox.contains(&layoutBox); }
90
91 bool inQuirksMode() const { return m_inQuirksMode; }
92 // For testing purposes only
93 void verifyAndOutputMismatchingLayoutTree(const RenderView&) const;
94
95private:
96 const Container& initialContainingBlock() const { return *m_initialContainingBlock; }
97 void layoutFormattingContextSubtree(const Box&);
98
99 WeakPtr<const Container> m_initialContainingBlock;
100 HashSet<const Container*> m_formattingContextRootListForLayout;
101 HashMap<const Box*, std::unique_ptr<FormattingState>> m_formattingStates;
102#ifndef NDEBUG
103 HashSet<const FormattingContext*> m_formattingContextList;
104#endif
105 mutable HashMap<const Box*, std::unique_ptr<Display::Box>> m_layoutToDisplayBox;
106 bool m_inQuirksMode { false };
107};
108
109#ifndef NDEBUG
110inline void LayoutState::registerFormattingContext(const FormattingContext& formattingContext)
111{
112 // Multiple formatting contexts of the same root within a layout frame indicates defective layout logic.
113 ASSERT(!m_formattingContextList.contains(&formattingContext));
114 m_formattingContextList.add(&formattingContext);
115}
116#endif
117
118}
119}
120#endif
121