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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
/*
* Copyright (C) 2011 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "RenderCombineText.h"
#include "RenderBlock.h"
#include "RenderStyleInlines.h"
#include "StyleInheritedData.h"
#include <wtf/NeverDestroyed.h>
#include <wtf/TZoneMallocInlines.h>
namespace WebCore {
WTF_MAKE_TZONE_OR_ISO_ALLOCATED_IMPL(RenderCombineText);
const float textCombineMargin = 1.15f; // Allow em + 15% margin
RenderCombineText::RenderCombineText(Text& textNode, const String& string)
: RenderText(Type::CombineText, textNode, string)
, m_isCombined(false)
, m_needsFontUpdate(false)
{
ASSERT(isRenderCombineText());
}
RenderCombineText::~RenderCombineText() = default;
void RenderCombineText::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
// FIXME: This is pretty hackish.
// Only cache a new font style if our old one actually changed. We do this to avoid
// clobbering width variants and shrink-to-fit changes, since we won't recombine when
// the font doesn't change.
if (!oldStyle || !oldStyle->fontCascadeEqual(style()))
m_combineFontStyle = RenderStyle::clonePtr(style());
RenderText::styleDidChange(diff, oldStyle);
if (m_isCombined && selfNeedsLayout()) {
// Layouts cause the text to be recombined; therefore, only only un-combine when the style diff causes a layout.
RenderText::setRenderedText(originalText()); // This RenderCombineText has been combined once. Restore the original text for the next combineText().
m_isCombined = false;
}
m_needsFontUpdate = true;
combineTextIfNeeded();
}
void RenderCombineText::setRenderedText(const String& text)
{
RenderText::setRenderedText(text);
m_needsFontUpdate = true;
combineTextIfNeeded();
}
std::optional<FloatPoint> RenderCombineText::computeTextOrigin(const FloatRect& boxRect) const
{
if (!m_isCombined)
return std::nullopt;
// Visually center m_combinedTextWidth/Ascent/Descent within boxRect
FloatPoint result = boxRect.minXMaxYCorner();
FloatSize combinedTextSize(m_combinedTextWidth, m_combinedTextAscent + m_combinedTextDescent);
result.move((boxRect.size().transposedSize() - combinedTextSize) / 2);
result.move(0, m_combinedTextAscent);
return result;
}
String RenderCombineText::combinedStringForRendering() const
{
if (m_isCombined) {
auto originalText = this->originalText();
ASSERT(!originalText.isNull());
return originalText;
}
return { };
}
void RenderCombineText::combineTextIfNeeded()
{
if (!m_needsFontUpdate)
return;
// An ancestor element may trigger us to lay out again, even when we're already combined.
if (m_isCombined)
RenderText::setRenderedText(originalText());
m_isCombined = false;
m_needsFontUpdate = false;
// text-combine-upright works only in vertical typographic mode.
if (!writingMode().isVerticalTypographic())
return;
auto description = originalFont().fontDescription();
float emWidth = description.computedSize() * textCombineMargin;
RefPtr fontSelector = style().fontCascade().fontSelector();
description.setOrientation(FontOrientation::Horizontal); // We are going to draw combined text horizontally.
FontCascade horizontalFont(FontCascadeDescription { description }, style().fontCascade());
horizontalFont.update(fontSelector.copyRef());
GlyphOverflow glyphOverflow;
glyphOverflow.computeBounds = true;
float combinedTextWidth = width(0, text().length(), horizontalFont, 0, nullptr, &glyphOverflow);
float bestFitDelta = combinedTextWidth - emWidth;
auto bestFitDescription = description;
m_isCombined = combinedTextWidth <= emWidth;
if (m_isCombined)
m_combineFontStyle->setFontDescription(WTFMove(description)); // Need to change font orientation to horizontal.
else {
// Need to try compressed glyphs.
static const FontWidthVariant widthVariants[] = { FontWidthVariant::HalfWidth, FontWidthVariant::ThirdWidth, FontWidthVariant::QuarterWidth };
for (auto widthVariant : widthVariants) {
description.setWidthVariant(widthVariant); // When modifying this, make sure to keep it in sync with FontPlatformData::isForTextCombine()!
FontCascade compressedFont(FontCascadeDescription { description }, style().fontCascade());
compressedFont.update(fontSelector.copyRef());
glyphOverflow.left = glyphOverflow.top = glyphOverflow.right = glyphOverflow.bottom = 0;
float runWidth = width(0, text().length(), compressedFont, 0, nullptr, &glyphOverflow);
if (runWidth <= emWidth) {
combinedTextWidth = runWidth;
m_isCombined = true;
// Replace my font with the new one.
m_combineFontStyle->setFontDescription(WTFMove(description));
break;
}
float widthDelta = runWidth - emWidth;
if (widthDelta < bestFitDelta) {
bestFitDelta = widthDelta;
bestFitDescription = description;
}
}
}
if (!m_isCombined) {
float scaleFactor = std::max(0.4f, emWidth / (emWidth + bestFitDelta));
float originalSize = bestFitDescription.computedSize();
do {
float computedSize = originalSize * scaleFactor;
bestFitDescription.setComputedSize(computedSize);
m_combineFontStyle->setFontDescription(FontCascadeDescription { bestFitDescription });
FontCascade compressedFont(FontCascadeDescription { bestFitDescription }, style().fontCascade());
compressedFont.update(fontSelector.copyRef());
glyphOverflow.left = glyphOverflow.top = glyphOverflow.right = glyphOverflow.bottom = 0;
float runWidth = width(0, text().length(), compressedFont, 0, nullptr, &glyphOverflow);
if (runWidth <= emWidth) {
combinedTextWidth = runWidth;
m_isCombined = true;
break;
}
scaleFactor -= 0.05f;
} while (scaleFactor >= 0.4f);
}
if (m_isCombined) {
static NeverDestroyed<String> objectReplacementCharacterString = span(objectReplacementCharacter);
RenderText::setRenderedText(objectReplacementCharacterString.get());
m_combinedTextWidth = combinedTextWidth;
m_combinedTextAscent = glyphOverflow.top;
m_combinedTextDescent = glyphOverflow.bottom;
setNeedsLayout();
}
}
} // namespace WebCore
|
