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/geometry/FloatRect.h"
29 #include "platform/text/TextDirection.h"
30 #include "wtf/RefCounted.h"
31 #include "wtf/text/WTFString.h"
32
33 namespace WebCore {
34
35 class FloatPoint;
36 class Font;
37 class GraphicsContext;
38 class GlyphBuffer;
39 class SimpleFontData;
40 struct GlyphData;
41 struct WidthIterator;
42
43 class PLATFORM_EXPORT TextRun {
44 WTF_MAKE_FAST_ALLOCATED;
45 public:
46 enum ExpansionBehaviorFlags {
47 ForbidTrailingExpansion = 0 << 0,
48 AllowTrailingExpansion = 1 << 0,
49 ForbidLeadingExpansion = 0 << 1,
50 AllowLeadingExpansion = 1 << 1,
51 };
52
53 typedef unsigned ExpansionBehavior;
54
55 enum RoundingHackFlags {
56 NoRounding = 0,
57 RunRounding = 1 << 0,
58 WordRounding = 1 << 1,
59 };
60
61 typedef unsigned RoundingHacks;
62
63 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)64 : m_charactersLength(len)
65 , m_len(len)
66 , m_xpos(xpos)
67 , m_horizontalGlyphStretch(1)
68 , m_expansion(expansion)
69 , m_expansionBehavior(expansionBehavior)
70 , m_is8Bit(true)
71 , m_allowTabs(false)
72 , m_direction(direction)
73 , m_directionalOverride(directionalOverride)
74 , m_characterScanForCodePath(characterScanForCodePath)
75 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
76 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
77 , m_disableSpacing(false)
78 , m_tabSize(0)
79 {
80 m_data.characters8 = c;
81 }
82
83 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)84 : m_charactersLength(len)
85 , m_len(len)
86 , m_xpos(xpos)
87 , m_horizontalGlyphStretch(1)
88 , m_expansion(expansion)
89 , m_expansionBehavior(expansionBehavior)
90 , m_is8Bit(false)
91 , m_allowTabs(false)
92 , m_direction(direction)
93 , m_directionalOverride(directionalOverride)
94 , m_characterScanForCodePath(characterScanForCodePath)
95 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
96 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
97 , m_disableSpacing(false)
98 , m_tabSize(0)
99 {
100 m_data.characters16 = c;
101 }
102
103 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)
104 : m_charactersLength(string.length())
105 , m_len(string.length())
106 , m_xpos(xpos)
107 , m_horizontalGlyphStretch(1)
108 , m_expansion(expansion)
109 , m_expansionBehavior(expansionBehavior)
110 , m_allowTabs(false)
111 , m_direction(direction)
112 , m_directionalOverride(directionalOverride)
113 , m_characterScanForCodePath(characterScanForCodePath)
114 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
115 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
116 , m_disableSpacing(false)
117 , m_tabSize(0)
118 {
119 if (!m_charactersLength) {
120 m_is8Bit = true;
121 m_data.characters8 = 0;
122 } else if (string.is8Bit()) {
123 m_data.characters8 = string.characters8();
124 m_is8Bit = true;
125 } else {
126 m_data.characters16 = string.characters16();
127 m_is8Bit = false;
128 }
129 }
130
131 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)
132 : m_charactersLength(string.length())
133 , m_len(string.length())
134 , m_xpos(xpos)
135 , m_horizontalGlyphStretch(1)
136 , m_expansion(expansion)
137 , m_expansionBehavior(expansionBehavior)
138 , m_allowTabs(false)
139 , m_direction(direction)
140 , m_directionalOverride(directionalOverride)
141 , m_characterScanForCodePath(characterScanForCodePath)
142 , m_applyRunRounding((roundingHacks & RunRounding) && s_allowsRoundingHacks)
143 , m_applyWordRounding((roundingHacks & WordRounding) && s_allowsRoundingHacks)
144 , m_disableSpacing(false)
145 , m_tabSize(0)
146 {
147 if (!m_charactersLength) {
148 m_is8Bit = true;
149 m_data.characters8 = 0;
150 } else if (string.is8Bit()) {
151 m_data.characters8 = string.characters8();
152 m_is8Bit = true;
153 } else {
154 m_data.characters16 = string.characters16();
155 m_is8Bit = false;
156 }
157 }
158
subRun(unsigned startOffset,unsigned length)159 TextRun subRun(unsigned startOffset, unsigned length) const
160 {
161 ASSERT(startOffset < m_len);
162
163 TextRun result = *this;
164
165 if (is8Bit()) {
166 result.setText(data8(startOffset), length);
167 return result;
168 }
169 result.setText(data16(startOffset), length);
170 return result;
171 }
172
173 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)174 const LChar* data8(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(is8Bit()); return &m_data.characters8[i]; }
data16(unsigned i)175 const UChar* data16(unsigned i) const { ASSERT_WITH_SECURITY_IMPLICATION(i < m_len); ASSERT(!is8Bit()); return &m_data.characters16[i]; }
176
characters8()177 const LChar* characters8() const { ASSERT(is8Bit()); return m_data.characters8; }
characters16()178 const UChar* characters16() const { ASSERT(!is8Bit()); return m_data.characters16; }
179
is8Bit()180 bool is8Bit() const { return m_is8Bit; }
length()181 int length() const { return m_len; }
charactersLength()182 int charactersLength() const { return m_charactersLength; }
183
setText(const LChar * c,unsigned len)184 void setText(const LChar* c, unsigned len) { m_data.characters8 = c; m_len = len; m_is8Bit = true;}
setText(const UChar * c,unsigned len)185 void setText(const UChar* c, unsigned len) { m_data.characters16 = c; m_len = len; m_is8Bit = false;}
186 void setText(const String&);
setCharactersLength(unsigned charactersLength)187 void setCharactersLength(unsigned charactersLength) { m_charactersLength = charactersLength; }
188
horizontalGlyphStretch()189 float horizontalGlyphStretch() const { return m_horizontalGlyphStretch; }
setHorizontalGlyphStretch(float scale)190 void setHorizontalGlyphStretch(float scale) { m_horizontalGlyphStretch = scale; }
191
allowTabs()192 bool allowTabs() const { return m_allowTabs; }
tabSize()193 unsigned tabSize() const { return m_tabSize; }
194 void setTabSize(bool, unsigned);
195
xPos()196 float xPos() const { return m_xpos; }
setXPos(float xPos)197 void setXPos(float xPos) { m_xpos = xPos; }
expansion()198 float expansion() const { return m_expansion; }
allowsLeadingExpansion()199 bool allowsLeadingExpansion() const { return m_expansionBehavior & AllowLeadingExpansion; }
allowsTrailingExpansion()200 bool allowsTrailingExpansion() const { return m_expansionBehavior & AllowTrailingExpansion; }
direction()201 TextDirection direction() const { return static_cast<TextDirection>(m_direction); }
rtl()202 bool rtl() const { return m_direction == RTL; }
ltr()203 bool ltr() const { return m_direction == LTR; }
directionalOverride()204 bool directionalOverride() const { return m_directionalOverride; }
characterScanForCodePath()205 bool characterScanForCodePath() const { return m_characterScanForCodePath; }
applyRunRounding()206 bool applyRunRounding() const { return m_applyRunRounding; }
applyWordRounding()207 bool applyWordRounding() const { return m_applyWordRounding; }
spacingDisabled()208 bool spacingDisabled() const { return m_disableSpacing; }
209
disableSpacing()210 void disableSpacing() { m_disableSpacing = true; }
disableRoundingHacks()211 void disableRoundingHacks() { m_applyRunRounding = m_applyWordRounding = false; }
setDirection(TextDirection direction)212 void setDirection(TextDirection direction) { m_direction = direction; }
setDirectionalOverride(bool override)213 void setDirectionalOverride(bool override) { m_directionalOverride = override; }
setCharacterScanForCodePath(bool scan)214 void setCharacterScanForCodePath(bool scan) { m_characterScanForCodePath = scan; }
215
216 class RenderingContext : public RefCounted<RenderingContext> {
217 public:
~RenderingContext()218 virtual ~RenderingContext() { }
219
220 virtual GlyphData glyphDataForCharacter(const Font&, const TextRun&, WidthIterator&, UChar32 character, bool mirror, int currentCharacter, unsigned& advanceLength) = 0;
221 virtual void drawSVGGlyphs(GraphicsContext*, const TextRun&, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const = 0;
222 virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, int& charsConsumed, String& glyphName) const = 0;
223 };
224
renderingContext()225 RenderingContext* renderingContext() const { return m_renderingContext.get(); }
setRenderingContext(PassRefPtr<RenderingContext> context)226 void setRenderingContext(PassRefPtr<RenderingContext> context) { m_renderingContext = context; }
227
228 static void setAllowsRoundingHacks(bool);
229 static bool allowsRoundingHacks();
230
231 private:
232 static bool s_allowsRoundingHacks;
233
234 union {
235 const LChar* characters8;
236 const UChar* characters16;
237 } m_data;
238 unsigned m_charactersLength; // Marks the end of the characters buffer. Default equals to m_len.
239 unsigned m_len;
240
241 // m_xpos is the x position relative to the left start of the text line, not relative to the left
242 // start of the containing block. In the case of right alignment or center alignment, left start of
243 // the text line is not the same as left start of the containing block.
244 float m_xpos;
245 float m_horizontalGlyphStretch;
246
247 float m_expansion;
248 ExpansionBehavior m_expansionBehavior : 2;
249 unsigned m_is8Bit : 1;
250 unsigned m_allowTabs : 1;
251 unsigned m_direction : 1;
252 unsigned m_directionalOverride : 1; // Was this direction set by an override character.
253 unsigned m_characterScanForCodePath : 1;
254 unsigned m_applyRunRounding : 1;
255 unsigned m_applyWordRounding : 1;
256 unsigned m_disableSpacing : 1;
257 unsigned m_tabSize;
258 RefPtr<RenderingContext> m_renderingContext;
259 };
260
setTabSize(bool allow,unsigned size)261 inline void TextRun::setTabSize(bool allow, unsigned size)
262 {
263 m_allowTabs = allow;
264 m_tabSize = size;
265 }
266
267 // Container for parameters needed to paint TextRun.
268 struct TextRunPaintInfo {
TextRunPaintInfoTextRunPaintInfo269 explicit TextRunPaintInfo(const TextRun& r)
270 : run(r)
271 , from(0)
272 , to(r.length())
273 {
274 }
275
276 const TextRun& run;
277 int from;
278 int to;
279 FloatRect bounds;
280 };
281
282 }
283 #endif
284