1/*
2 * Copyright (C) 2010 Alex Milowski (alex@milowski.com). All rights reserved.
3 * Copyright (C) 2012 David Barton (dbarton@mathscribe.com). All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#pragma once
28
29#if ENABLE(MATHML)
30
31#include "MathMLElement.h"
32#include "MathMLStyle.h"
33#include "RenderBlock.h"
34#include "RenderTable.h"
35#include "StyleInheritedData.h"
36
37namespace WebCore {
38
39class RenderMathMLOperator;
40class MathMLPresentationElement;
41
42class RenderMathMLBlock : public RenderBlock {
43 WTF_MAKE_ISO_ALLOCATED(RenderMathMLBlock);
44public:
45 RenderMathMLBlock(MathMLPresentationElement&, RenderStyle&&);
46 RenderMathMLBlock(Document&, RenderStyle&&);
47 virtual ~RenderMathMLBlock();
48
49 MathMLStyle& mathMLStyle() const { return m_mathMLStyle; }
50
51 bool isChildAllowed(const RenderObject&, const RenderStyle&) const override;
52
53 // MathML defines an "embellished operator" as roughly an <mo> that may have subscripts,
54 // superscripts, underscripts, overscripts, or a denominator (as in d/dx, where "d" is some
55 // differential operator). The padding, precedence, and stretchiness of the base <mo> should
56 // apply to the embellished operator as a whole. unembellishedOperator() checks for being an
57 // embellished operator, and omits any embellishments.
58 // FIXME: We don't yet handle all the cases in the MathML spec. See
59 // https://bugs.webkit.org/show_bug.cgi?id=78617.
60 virtual RenderMathMLOperator* unembellishedOperator() const { return 0; }
61
62 int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const override;
63
64#if ENABLE(DEBUG_MATH_LAYOUT)
65 virtual void paint(PaintInfo&, const LayoutPoint&);
66#endif
67
68protected:
69 LayoutUnit ruleThicknessFallback() const
70 {
71 // This function returns a value for the default rule thickness (TeX's \xi_8) to be used as a fallback when we lack a MATH table.
72 // This arbitrary value of 0.05em was used in early WebKit MathML implementations for the thickness of the fraction bars.
73 // Note that Gecko has a slower but more accurate version that measures the thickness of U+00AF MACRON to be more accurate and otherwise fallback to some arbitrary value.
74 return 0.05f * style().fontCascade().size();
75 }
76
77 LayoutUnit mathAxisHeight() const;
78 LayoutUnit mirrorIfNeeded(LayoutUnit horizontalOffset, LayoutUnit boxWidth = 0_lu) const;
79 LayoutUnit mirrorIfNeeded(LayoutUnit horizontalOffset, const RenderBox& child) const { return mirrorIfNeeded(horizontalOffset, child.logicalWidth()); }
80
81 static LayoutUnit ascentForChild(const RenderBox& child)
82 {
83 return child.firstLineBaseline().valueOr(child.logicalHeight());
84 }
85
86 void layoutBlock(bool relayoutChildren, LayoutUnit pageLogicalHeight = 0_lu) override;
87 void layoutInvalidMarkup(bool relayoutChildren);
88
89private:
90 bool isRenderMathMLBlock() const final { return true; }
91 const char* renderName() const override { return "RenderMathMLBlock"; }
92 bool avoidsFloats() const final { return true; }
93 bool canDropAnonymousBlockChild() const final { return false; }
94 void layoutItems(bool relayoutChildren);
95
96 Ref<MathMLStyle> m_mathMLStyle;
97};
98
99class RenderMathMLTable final : public RenderTable {
100 WTF_MAKE_ISO_ALLOCATED(RenderMathMLTable);
101public:
102 explicit RenderMathMLTable(MathMLElement& element, RenderStyle&& style)
103 : RenderTable(element, WTFMove(style))
104 , m_mathMLStyle(MathMLStyle::create())
105 {
106 }
107
108
109 MathMLStyle& mathMLStyle() const { return m_mathMLStyle; }
110
111private:
112 bool isRenderMathMLTable() const final { return true; }
113 const char* renderName() const final { return "RenderMathMLTable"; }
114 Optional<int> firstLineBaseline() const final;
115
116 Ref<MathMLStyle> m_mathMLStyle;
117};
118
119LayoutUnit toUserUnits(const MathMLElement::Length&, const RenderStyle&, const LayoutUnit& referenceValue);
120
121} // namespace WebCore
122
123SPECIALIZE_TYPE_TRAITS_RENDER_OBJECT(RenderMathMLBlock, isRenderMathMLBlock())
124SPECIALIZE_TYPE_TRAITS_RENDER_OBJECT(RenderMathMLTable, isRenderMathMLTable())
125
126#endif // ENABLE(MATHML)
127