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 WebCore {
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 enum RoundingHackFlags {
58 NoRounding = 0,
59 RunRounding = 1 << 0,
60 WordRounding = 1 << 1,
61 };
62
63 typedef unsigned RoundingHacks;
64
65 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, RoundingHacks roundingHacks = RunRounding | WordRounding)
m_charactersLength(len)66 : m_charactersLength(len)
67 , m_len(len)
68 , m_xpos(xpos)
69 , m_horizontalGlyphStretch(1)
70 , m_expansion(expansion)
71 , m_expansionBehavior(expansionBehavior)
72 , m_is8Bit(true)
73 , m_allowTabs(false)
74 , m_direction(direction)
75 , m_directionalOverride(directionalOverride)
76 , m_characterScanForCodePath(characterScanForCodePath)
77 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
78 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
79 , m_disableSpacing(false)
80 , m_tabSize(0)
81 {
82 m_data.characters8 = c;
83 }
84
85 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, RoundingHacks roundingHacks = RunRounding | WordRounding)
m_charactersLength(len)86 : m_charactersLength(len)
87 , m_len(len)
88 , m_xpos(xpos)
89 , m_horizontalGlyphStretch(1)
90 , m_expansion(expansion)
91 , m_expansionBehavior(expansionBehavior)
92 , m_is8Bit(false)
93 , m_allowTabs(false)
94 , m_direction(direction)
95 , m_directionalOverride(directionalOverride)
96 , m_characterScanForCodePath(characterScanForCodePath)
97 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
98 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
99 , m_disableSpacing(false)
100 , m_tabSize(0)
101 {
102 m_data.characters16 = c;
103 }
104
105 TextRun(const String& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true, RoundingHacks roundingHacks = RunRounding | WordRounding)
106 : m_charactersLength(string.length())
107 , m_len(string.length())
108 , m_xpos(xpos)
109 , m_horizontalGlyphStretch(1)
110 , m_expansion(expansion)
111 , m_expansionBehavior(expansionBehavior)
112 , m_allowTabs(false)
113 , m_direction(direction)
114 , m_directionalOverride(directionalOverride)
115 , m_characterScanForCodePath(characterScanForCodePath)
116 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
117 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
118 , m_disableSpacing(false)
119 , m_tabSize(0)
120 {
121 if (!m_charactersLength) {
122 m_is8Bit = true;
123 m_data.characters8 = 0;
124 } else if (string.is8Bit()) {
125 m_data.characters8 = string.characters8();
126 m_is8Bit = true;
127 } else {
128 m_data.characters16 = string.characters16();
129 m_is8Bit = false;
130 }
131 }
132
133 TextRun(const StringView& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false, bool characterScanForCodePath = true, RoundingHacks roundingHacks = RunRounding | WordRounding)
134 : m_charactersLength(string.length())
135 , m_len(string.length())
136 , m_xpos(xpos)
137 , m_horizontalGlyphStretch(1)
138 , m_expansion(expansion)
139 , m_expansionBehavior(expansionBehavior)
140 , m_allowTabs(false)
141 , m_direction(direction)
142 , m_directionalOverride(directionalOverride)
143 , m_characterScanForCodePath(characterScanForCodePath)
144 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
145 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
146 , m_disableSpacing(false)
147 , m_tabSize(0)
148 {
149 if (!m_charactersLength) {
150 m_is8Bit = true;
151 m_data.characters8 = 0;
152 } else if (string.is8Bit()) {
153 m_data.characters8 = string.characters8();
154 m_is8Bit = true;
155 } else {
156 m_data.characters16 = string.characters16();
157 m_is8Bit = false;
158 }
159 }
160
subRun(unsigned startOffset,unsigned length)161 TextRun subRun(unsigned startOffset, unsigned length) const
162 {
163 ASSERT(startOffset < m_len);
164
165 TextRun result = *this;
166
167 if (is8Bit()) {
168 result.setText(data8(startOffset), length);
169 return result;
170 }
171 result.setText(data16(startOffset), length);
172 return result;
173 }
174
175 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)176 const LChar* data8(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(is8Bit()); return &m_data.characters8[i]; }
data16(unsigned i)177 const UChar* data16(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(!is8Bit()); return &m_data.characters16[i]; }
178
characters8()179 const LChar* characters8() const { ASSERT(is8Bit()); return m_data.characters8; }
characters16()180 const UChar* characters16() const { ASSERT(!is8Bit()); return m_data.characters16; }
181
is8Bit()182 bool is8Bit() const { return m_is8Bit; }
length()183 int length() const { return m_len; }
charactersLength()184 int charactersLength() const { return m_charactersLength; }
185
setText(const LChar * c,unsigned len)186 void setText(const LChar* c, unsigned len) { m_data.characters8 = c; m_len = len; m_is8Bit = true;}
setText(const UChar * c,unsigned len)187 void setText(const UChar* c, unsigned len) { m_data.characters16 = c; m_len = len; m_is8Bit = false;}
188 void setText(const String&);
setCharactersLength(unsigned charactersLength)189 void setCharactersLength(unsigned charactersLength) { m_charactersLength = charactersLength; }
190
horizontalGlyphStretch()191 float horizontalGlyphStretch() const { return m_horizontalGlyphStretch; }
setHorizontalGlyphStretch(float scale)192 void setHorizontalGlyphStretch(float scale) { m_horizontalGlyphStretch = scale; }
193
allowTabs()194 bool allowTabs() const { return m_allowTabs; }
tabSize()195 unsigned tabSize() const { return m_tabSize; }
196 void setTabSize(bool, unsigned);
197
xPos()198 float xPos() const { return m_xpos; }
setXPos(float xPos)199 void setXPos(float xPos) { m_xpos = xPos; }
expansion()200 float expansion() const { return m_expansion; }
allowsLeadingExpansion()201 bool allowsLeadingExpansion() const { return m_expansionBehavior & AllowLeadingExpansion; }
allowsTrailingExpansion()202 bool allowsTrailingExpansion() const { return m_expansionBehavior & AllowTrailingExpansion; }
direction()203 TextDirection direction() const { return static_cast<TextDirection>(m_direction); }
rtl()204 bool rtl() const { return m_direction == RTL; }
ltr()205 bool ltr() const { return m_direction == LTR; }
directionalOverride()206 bool directionalOverride() const { return m_directionalOverride; }
characterScanForCodePath()207 bool characterScanForCodePath() const { return m_characterScanForCodePath; }
applyRunRounding()208 bool applyRunRounding() const { return m_applyRunRounding; }
applyWordRounding()209 bool applyWordRounding() const { return m_applyWordRounding; }
spacingDisabled()210 bool spacingDisabled() const { return m_disableSpacing; }
211
disableSpacing()212 void disableSpacing() { m_disableSpacing = true; }
disableRoundingHacks()213 void disableRoundingHacks() { m_applyRunRounding = m_applyWordRounding = false; }
setDirection(TextDirection direction)214 void setDirection(TextDirection direction) { m_direction = direction; }
setDirectionalOverride(bool override)215 void setDirectionalOverride(bool override) { m_directionalOverride = override; }
setCharacterScanForCodePath(bool scan)216 void setCharacterScanForCodePath(bool scan) { m_characterScanForCodePath = scan; }
217
218 class RenderingContext : public RefCounted<RenderingContext> {
219 public:
~RenderingContext()220 virtual ~RenderingContext() { }
221
222 virtual GlyphData glyphDataForCharacter(const Font&, const TextRun&, WidthIterator&, UChar32 character, bool mirror, int currentCharacter, unsigned& advanceLength) = 0;
223 virtual void drawSVGGlyphs(GraphicsContext*, const TextRun&, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const = 0;
224 virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, int& charsConsumed, Glyph& glyphId) const = 0;
225 };
226
renderingContext()227 RenderingContext* renderingContext() const { return m_renderingContext.get(); }
setRenderingContext(PassRefPtr<RenderingContext> context)228 void setRenderingContext(PassRefPtr<RenderingContext> context) { m_renderingContext = context; }
229
230 static void setAllowsRoundingHacks(bool);
231 static bool allowsRoundingHacks();
232
233 private:
234 static bool s_allowsRoundingHacks;
235
236 union {
237 const LChar* characters8;
238 const UChar* characters16;
239 } m_data;
240 unsigned m_charactersLength; // Marks the end of the characters buffer. Default equals to m_len.
241 unsigned m_len;
242
243 // m_xpos is the x position relative to the left start of the text line, not relative to the left
244 // start of the containing block. In the case of right alignment or center alignment, left start of
245 // the text line is not the same as left start of the containing block.
246 float m_xpos;
247 float m_horizontalGlyphStretch;
248
249 float m_expansion;
250 ExpansionBehavior m_expansionBehavior : 2;
251 unsigned m_is8Bit : 1;
252 unsigned m_allowTabs : 1;
253 unsigned m_direction : 1;
254 unsigned m_directionalOverride : 1; // Was this direction set by an override character.
255 unsigned m_characterScanForCodePath : 1;
256 unsigned m_applyRunRounding : 1;
257 unsigned m_applyWordRounding : 1;
258 unsigned m_disableSpacing : 1;
259 unsigned m_tabSize;
260 RefPtr<RenderingContext> m_renderingContext;
261 };
262
setTabSize(bool allow,unsigned size)263 inline void TextRun::setTabSize(bool allow, unsigned size)
264 {
265 m_allowTabs = allow;
266 m_tabSize = size;
267 }
268
269 // Container for parameters needed to paint TextRun.
270 struct TextRunPaintInfo {
TextRunPaintInfoTextRunPaintInfo271 explicit TextRunPaintInfo(const TextRun& r)
272 : run(r)
273 , from(0)
274 , to(r.length())
275 {
276 }
277
278 const TextRun& run;
279 int from;
280 int to;
281 FloatRect bounds;
282 };
283
284 }
285 #endif
286