1 /*
2 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
3 * (C) 2000 Antti Koivisto (koivisto@kde.org)
4 * (C) 2000 Dirk Mueller (mueller@kde.org)
5 * Copyright (C) 2003, 2006, 2007, 2011 Apple Inc. All rights reserved.
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public License
18 * along with this library; see the file COPYING.LIB. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 *
22 */
23
24 #ifndef TextRun_h
25 #define TextRun_h
26
27 #include "platform/PlatformExport.h"
28 #include "platform/fonts/Glyph.h"
29 #include "platform/geometry/FloatRect.h"
30 #include "platform/text/TextDirection.h"
31 #include "platform/text/TextPath.h"
32 #include "wtf/RefCounted.h"
33 #include "wtf/text/WTFString.h"
34
35 namespace blink {
36
37 class FloatPoint;
38 class Font;
39 class GraphicsContext;
40 class GlyphBuffer;
41 class SimpleFontData;
42 struct GlyphData;
43 struct WidthIterator;
44
45 class PLATFORM_EXPORT TextRun {
46 WTF_MAKE_FAST_ALLOCATED;
47 public:
48 enum ExpansionBehaviorFlags {
49 ForbidTrailingExpansion = 0 << 0,
50 AllowTrailingExpansion = 1 << 0,
51 ForbidLeadingExpansion = 0 << 1,
52 AllowLeadingExpansion = 1 << 1,
53 };
54
55 typedef unsigned ExpansionBehavior;
56
57 TextRun(const LChar* c, unsigned len, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true)
m_charactersLength(len)58 : m_charactersLength(len)
59 , m_len(len)
60 , m_xpos(xpos)
61 , m_horizontalGlyphStretch(1)
62 , m_expansion(expansion)
63 , m_expansionBehavior(expansionBehavior)
64 , m_is8Bit(true)
65 , m_allowTabs(false)
66 , m_direction(direction)
67 , m_directionalOverride(directionalOverride)
68 , m_characterScanForCodePath(characterScanForCodePath)
69 , m_useComplexCodePath(false)
70 , m_disableSpacing(false)
71 , m_tabSize(0)
72 , m_normalizeSpace(false)
73 {
74 m_data.characters8 = c;
75 }
76
77 TextRun(const UChar* c, unsigned len, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true)
m_charactersLength(len)78 : m_charactersLength(len)
79 , m_len(len)
80 , m_xpos(xpos)
81 , m_horizontalGlyphStretch(1)
82 , m_expansion(expansion)
83 , m_expansionBehavior(expansionBehavior)
84 , m_is8Bit(false)
85 , m_allowTabs(false)
86 , m_direction(direction)
87 , m_directionalOverride(directionalOverride)
88 , m_characterScanForCodePath(characterScanForCodePath)
89 , m_useComplexCodePath(false)
90 , m_disableSpacing(false)
91 , m_tabSize(0)
92 , m_normalizeSpace(false)
93 {
94 m_data.characters16 = c;
95 }
96
97 TextRun(const String& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true, bool normalizeSpace = false)
98 : m_charactersLength(string.length())
99 , m_len(string.length())
100 , m_xpos(xpos)
101 , m_horizontalGlyphStretch(1)
102 , m_expansion(expansion)
103 , m_expansionBehavior(expansionBehavior)
104 , m_allowTabs(false)
105 , m_direction(direction)
106 , m_directionalOverride(directionalOverride)
107 , m_characterScanForCodePath(characterScanForCodePath)
108 , m_useComplexCodePath(false)
109 , m_disableSpacing(false)
110 , m_tabSize(0)
111 , m_normalizeSpace(normalizeSpace)
112 {
113 if (!m_charactersLength) {
114 m_is8Bit = true;
115 m_data.characters8 = 0;
116 } else if (string.is8Bit()) {
117 m_data.characters8 = string.characters8();
118 m_is8Bit = true;
119 } else {
120 m_data.characters16 = string.characters16();
121 m_is8Bit = false;
122 }
123 }
124
125 TextRun(const StringView& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true, bool normalizeSpace = false)
126 : m_charactersLength(string.length())
127 , m_len(string.length())
128 , m_xpos(xpos)
129 , m_horizontalGlyphStretch(1)
130 , m_expansion(expansion)
131 , m_expansionBehavior(expansionBehavior)
132 , m_allowTabs(false)
133 , m_direction(direction)
134 , m_directionalOverride(directionalOverride)
135 , m_characterScanForCodePath(characterScanForCodePath)
136 , m_useComplexCodePath(false)
137 , m_disableSpacing(false)
138 , m_tabSize(0)
139 , m_normalizeSpace(normalizeSpace)
140 {
141 if (!m_charactersLength) {
142 m_is8Bit = true;
143 m_data.characters8 = 0;
144 } else if (string.is8Bit()) {
145 m_data.characters8 = string.characters8();
146 m_is8Bit = true;
147 } else {
148 m_data.characters16 = string.characters16();
149 m_is8Bit = false;
150 }
151 }
152
subRun(unsigned startOffset,unsigned length)153 TextRun subRun(unsigned startOffset, unsigned length) const
154 {
155 ASSERT(startOffset < m_len);
156
157 TextRun result = *this;
158
159 if (is8Bit()) {
160 result.setText(data8(startOffset), length);
161 return result;
162 }
163 result.setText(data16(startOffset), length);
164 return result;
165 }
166
167 UChar operator[](unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); return is8Bit() ? m_data.characters8[i] :m_data.characters16[i]; }
data8(unsigned i)168 const LChar* data8(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(is8Bit()); return &m_data.characters8[i]; }
data16(unsigned i)169 const UChar* data16(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(!is8Bit()); return &m_data.characters16[i]; }
170
characters8()171 const LChar* characters8() const { ASSERT(is8Bit()); return m_data.characters8; }
characters16()172 const UChar* characters16() const { ASSERT(!is8Bit()); return m_data.characters16; }
173
is8Bit()174 bool is8Bit() const { return m_is8Bit; }
length()175 int length() const { return m_len; }
charactersLength()176 int charactersLength() const { return m_charactersLength; }
177
normalizeSpace()178 bool normalizeSpace() const { return m_normalizeSpace; }
setNormalizeSpace(bool normalizeSpace)179 void setNormalizeSpace(bool normalizeSpace) { m_normalizeSpace = normalizeSpace; }
180
setText(const LChar * c,unsigned len)181 void setText(const LChar* c, unsigned len) { m_data.characters8 = c; m_len = len; m_is8Bit = true;}
setText(const UChar * c,unsigned len)182 void setText(const UChar* c, unsigned len) { m_data.characters16 = c; m_len = len; m_is8Bit = false;}
183 void setText(const String&);
setCharactersLength(unsigned charactersLength)184 void setCharactersLength(unsigned charactersLength) { m_charactersLength = charactersLength; }
185
horizontalGlyphStretch()186 float horizontalGlyphStretch() const { return m_horizontalGlyphStretch; }
setHorizontalGlyphStretch(float scale)187 void setHorizontalGlyphStretch(float scale) { m_horizontalGlyphStretch = scale; }
188
allowTabs()189 bool allowTabs() const { return m_allowTabs; }
tabSize()190 unsigned tabSize() const { return m_tabSize; }
191 void setTabSize(bool, unsigned);
192
xPos()193 float xPos() const { return m_xpos; }
setXPos(float xPos)194 void setXPos(float xPos) { m_xpos = xPos; }
expansion()195 float expansion() const { return m_expansion; }
allowsLeadingExpansion()196 bool allowsLeadingExpansion() const { return m_expansionBehavior & AllowLeadingExpansion; }
allowsTrailingExpansion()197 bool allowsTrailingExpansion() const { return m_expansionBehavior & AllowTrailingExpansion; }
direction()198 TextDirection direction() const { return static_cast<TextDirection>(m_direction); }
rtl()199 bool rtl() const { return m_direction == RTL; }
ltr()200 bool ltr() const { return m_direction == LTR; }
directionalOverride()201 bool directionalOverride() const { return m_directionalOverride; }
characterScanForCodePath()202 bool characterScanForCodePath() const { return m_characterScanForCodePath; }
useComplexCodePath()203 bool useComplexCodePath() const { return m_useComplexCodePath; }
spacingDisabled()204 bool spacingDisabled() const { return m_disableSpacing; }
205
disableSpacing()206 void disableSpacing() { m_disableSpacing = true; }
setDirection(TextDirection direction)207 void setDirection(TextDirection direction) { m_direction = direction; }
setDirectionalOverride(bool override)208 void setDirectionalOverride(bool override) { m_directionalOverride = override; }
setCharacterScanForCodePath(bool scan)209 void setCharacterScanForCodePath(bool scan) { m_characterScanForCodePath = scan; }
setUseComplexCodePath(bool useComplex)210 void setUseComplexCodePath(bool useComplex) { m_useComplexCodePath = useComplex; }
211
212 class RenderingContext : public RefCounted<RenderingContext> {
213 public:
~RenderingContext()214 virtual ~RenderingContext() { }
215
216 virtual GlyphData glyphDataForCharacter(const Font&, const TextRun&, WidthIterator&, UChar32 character, bool mirror, int currentCharacter, unsigned& advanceLength) = 0;
217 virtual void drawSVGGlyphs(GraphicsContext*, const TextRun&, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const = 0;
218 virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, int& charsConsumed, Glyph& glyphId) const = 0;
219 };
220
renderingContext()221 RenderingContext* renderingContext() const { return m_renderingContext.get(); }
setRenderingContext(PassRefPtr<RenderingContext> context)222 void setRenderingContext(PassRefPtr<RenderingContext> context) { m_renderingContext = context; }
223
224 private:
225 union {
226 const LChar* characters8;
227 const UChar* characters16;
228 } m_data;
229 unsigned m_charactersLength; // Marks the end of the characters buffer. Default equals to m_len.
230 unsigned m_len;
231
232 // m_xpos is the x position relative to the left start of the text line, not relative to the left
233 // start of the containing block. In the case of right alignment or center alignment, left start of
234 // the text line is not the same as left start of the containing block.
235 float m_xpos;
236 float m_horizontalGlyphStretch;
237
238 float m_expansion;
239 ExpansionBehavior m_expansionBehavior : 2;
240 unsigned m_is8Bit : 1;
241 unsigned m_allowTabs : 1;
242 unsigned m_direction : 1;
243 unsigned m_directionalOverride : 1; // Was this direction set by an override character.
244 unsigned m_characterScanForCodePath : 1;
245 unsigned m_useComplexCodePath : 1;
246 unsigned m_disableSpacing : 1;
247 unsigned m_tabSize;
248 bool m_normalizeSpace;
249 RefPtr<RenderingContext> m_renderingContext;
250 };
251
setTabSize(bool allow,unsigned size)252 inline void TextRun::setTabSize(bool allow, unsigned size)
253 {
254 m_allowTabs = allow;
255 m_tabSize = size;
256 }
257
258 // Container for parameters needed to paint TextRun.
259 struct TextRunPaintInfo {
TextRunPaintInfoTextRunPaintInfo260 explicit TextRunPaintInfo(const TextRun& r)
261 : run(r)
262 , from(0)
263 , to(r.length())
264 {
265 }
266
267 const TextRun& run;
268 int from;
269 int to;
270 FloatRect bounds;
271 };
272
273 }
274 #endif
275