1 /*
2 * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
3 * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
4 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public License
17 * along with this library; see the file COPYING.LIB. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 #include "config.h"
23
24 #if ENABLE(SVG_FONTS)
25 #include "core/svg/SVGFontElement.h"
26
27 #include "core/frame/UseCounter.h"
28 #include "core/svg/SVGGlyphElement.h"
29 #include "core/svg/SVGHKernElement.h"
30 #include "core/svg/SVGMissingGlyphElement.h"
31 #include "core/svg/SVGVKernElement.h"
32 #include "wtf/ASCIICType.h"
33
34 namespace WebCore {
35
36 // Animated property definitions
DEFINE_ANIMATED_BOOLEAN(SVGFontElement,SVGNames::externalResourcesRequiredAttr,ExternalResourcesRequired,externalResourcesRequired)37 DEFINE_ANIMATED_BOOLEAN(SVGFontElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)
38
39 BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGFontElement)
40 REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
41 REGISTER_PARENT_ANIMATED_PROPERTIES(SVGElement)
42 END_REGISTER_ANIMATED_PROPERTIES
43
44 inline SVGFontElement::SVGFontElement(Document& document)
45 : SVGElement(SVGNames::fontTag, document)
46 , m_missingGlyph(0)
47 , m_isGlyphCacheValid(false)
48 {
49 ScriptWrappable::init(this);
50 registerAnimatedPropertiesForSVGFontElement();
51
52 UseCounter::count(document, UseCounter::SVGFontElement);
53 }
54
create(Document & document)55 PassRefPtr<SVGFontElement> SVGFontElement::create(Document& document)
56 {
57 return adoptRef(new SVGFontElement(document));
58 }
59
invalidateGlyphCache()60 void SVGFontElement::invalidateGlyphCache()
61 {
62 if (m_isGlyphCacheValid) {
63 m_glyphMap.clear();
64 m_horizontalKerningPairs.clear();
65 m_verticalKerningPairs.clear();
66 }
67 m_isGlyphCacheValid = false;
68 }
69
firstMissingGlyphElement() const70 SVGMissingGlyphElement* SVGFontElement::firstMissingGlyphElement() const
71 {
72 for (Node* child = firstChild(); child; child = child->nextSibling()) {
73 if (child->hasTagName(SVGNames::missing_glyphTag))
74 return toSVGMissingGlyphElement(child);
75 }
76
77 return 0;
78 }
79
registerLigaturesInGlyphCache(Vector<String> & ligatures)80 void SVGFontElement::registerLigaturesInGlyphCache(Vector<String>& ligatures)
81 {
82 ASSERT(!ligatures.isEmpty());
83
84 // Register each character of a ligature in the map, if not present.
85 // Eg. If only a "fi" ligature is present, but not "f" and "i", the
86 // GlyphPage will not contain any entries for "f" and "i", so the
87 // SVGFont is not used to render the text "fi1234". Register an
88 // empty SVGGlyph with the character, so the SVG Font will be used
89 // to render the text. If someone tries to render "f2" the SVG Font
90 // will not be able to find a glyph for "f", but handles the fallback
91 // character substitution properly through glyphDataForCharacter().
92 Vector<SVGGlyph> glyphs;
93 size_t ligaturesSize = ligatures.size();
94 for (size_t i = 0; i < ligaturesSize; ++i) {
95 const String& unicode = ligatures[i];
96
97 unsigned unicodeLength = unicode.length();
98 ASSERT(unicodeLength > 1);
99
100 for (unsigned i = 0; i < unicodeLength; ++i) {
101 String lookupString = unicode.substring(i, 1);
102 m_glyphMap.collectGlyphsForString(lookupString, glyphs);
103 if (!glyphs.isEmpty()) {
104 glyphs.clear();
105 continue;
106 }
107
108 // This glyph is never meant to be used for rendering, only as identifier as a part of a ligature.
109 SVGGlyph newGlyphPart;
110 newGlyphPart.isPartOfLigature = true;
111 m_glyphMap.addGlyph(String(), lookupString, newGlyphPart);
112 }
113 }
114 }
115
ensureGlyphCache()116 void SVGFontElement::ensureGlyphCache()
117 {
118 if (m_isGlyphCacheValid)
119 return;
120
121 SVGMissingGlyphElement* firstMissingGlyphElement = 0;
122 Vector<String> ligatures;
123 for (Node* child = firstChild(); child; child = child->nextSibling()) {
124 if (child->hasTagName(SVGNames::glyphTag)) {
125 SVGGlyphElement* glyph = toSVGGlyphElement(child);
126 AtomicString unicode = glyph->fastGetAttribute(SVGNames::unicodeAttr);
127 AtomicString glyphId = glyph->getIdAttribute();
128 if (glyphId.isEmpty() && unicode.isEmpty())
129 continue;
130
131 m_glyphMap.addGlyph(glyphId, unicode, glyph->buildGlyphIdentifier());
132
133 // Register ligatures, if needed, don't mix up with surrogate pairs though!
134 if (unicode.length() > 1 && !U16_IS_SURROGATE(unicode[0]))
135 ligatures.append(unicode.string());
136 } else if (child->hasTagName(SVGNames::hkernTag)) {
137 toSVGHKernElement(child)->buildHorizontalKerningPair(m_horizontalKerningPairs);
138 } else if (child->hasTagName(SVGNames::vkernTag)) {
139 toSVGVKernElement(child)->buildVerticalKerningPair(m_verticalKerningPairs);
140 } else if (child->hasTagName(SVGNames::missing_glyphTag) && !firstMissingGlyphElement) {
141 firstMissingGlyphElement = toSVGMissingGlyphElement(child);
142 }
143 }
144
145 // Register each character of each ligature, if needed.
146 if (!ligatures.isEmpty())
147 registerLigaturesInGlyphCache(ligatures);
148
149 // Register missing-glyph element, if present.
150 if (firstMissingGlyphElement) {
151 SVGGlyph svgGlyph = SVGGlyphElement::buildGenericGlyphIdentifier(firstMissingGlyphElement);
152 m_glyphMap.appendToGlyphTable(svgGlyph);
153 m_missingGlyph = svgGlyph.tableEntry;
154 ASSERT(m_missingGlyph > 0);
155 }
156
157 m_isGlyphCacheValid = true;
158 }
159
stringMatchesUnicodeRange(const String & unicodeString,const UnicodeRanges & ranges,const HashSet<String> & unicodeValues)160 static bool stringMatchesUnicodeRange(const String& unicodeString, const UnicodeRanges& ranges, const HashSet<String>& unicodeValues)
161 {
162 if (unicodeString.isEmpty())
163 return false;
164
165 if (!ranges.isEmpty()) {
166 UChar firstChar = unicodeString[0];
167 const UnicodeRanges::const_iterator end = ranges.end();
168 for (UnicodeRanges::const_iterator it = ranges.begin(); it != end; ++it) {
169 if (firstChar >= it->first && firstChar <= it->second)
170 return true;
171 }
172 }
173
174 if (!unicodeValues.isEmpty())
175 return unicodeValues.contains(unicodeString);
176
177 return false;
178 }
179
stringMatchesGlyphName(const String & glyphName,const HashSet<String> & glyphValues)180 static bool stringMatchesGlyphName(const String& glyphName, const HashSet<String>& glyphValues)
181 {
182 if (glyphName.isEmpty())
183 return false;
184
185 if (!glyphValues.isEmpty())
186 return glyphValues.contains(glyphName);
187
188 return false;
189 }
190
matches(const String & u1,const String & g1,const String & u2,const String & g2,const SVGKerningPair & kerningPair)191 static bool matches(const String& u1, const String& g1, const String& u2, const String& g2, const SVGKerningPair& kerningPair)
192 {
193 if (!stringMatchesUnicodeRange(u1, kerningPair.unicodeRange1, kerningPair.unicodeName1)
194 && !stringMatchesGlyphName(g1, kerningPair.glyphName1))
195 return false;
196
197 if (!stringMatchesUnicodeRange(u2, kerningPair.unicodeRange2, kerningPair.unicodeName2)
198 && !stringMatchesGlyphName(g2, kerningPair.glyphName2))
199 return false;
200
201 return true;
202 }
203
kerningForPairOfStringsAndGlyphs(const KerningPairVector & kerningPairs,const String & u1,const String & g1,const String & u2,const String & g2)204 static float kerningForPairOfStringsAndGlyphs(const KerningPairVector& kerningPairs, const String& u1, const String& g1, const String& u2, const String& g2)
205 {
206 KerningPairVector::const_iterator it = kerningPairs.end() - 1;
207 const KerningPairVector::const_iterator begin = kerningPairs.begin() - 1;
208 for (; it != begin; --it) {
209 if (matches(u1, g1, u2, g2, *it))
210 return it->kerning;
211 }
212
213 return 0;
214 }
215
horizontalKerningForPairOfStringsAndGlyphs(const String & u1,const String & g1,const String & u2,const String & g2) const216 float SVGFontElement::horizontalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
217 {
218 if (m_horizontalKerningPairs.isEmpty())
219 return 0;
220
221 return kerningForPairOfStringsAndGlyphs(m_horizontalKerningPairs, u1, g1, u2, g2);
222 }
223
verticalKerningForPairOfStringsAndGlyphs(const String & u1,const String & g1,const String & u2,const String & g2) const224 float SVGFontElement::verticalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
225 {
226 if (m_verticalKerningPairs.isEmpty())
227 return 0;
228
229 return kerningForPairOfStringsAndGlyphs(m_verticalKerningPairs, u1, g1, u2, g2);
230 }
231
collectGlyphsForString(const String & string,Vector<SVGGlyph> & glyphs)232 void SVGFontElement::collectGlyphsForString(const String& string, Vector<SVGGlyph>& glyphs)
233 {
234 ensureGlyphCache();
235 m_glyphMap.collectGlyphsForString(string, glyphs);
236 }
237
collectGlyphsForGlyphName(const String & glyphName,Vector<SVGGlyph> & glyphs)238 void SVGFontElement::collectGlyphsForGlyphName(const String& glyphName, Vector<SVGGlyph>& glyphs)
239 {
240 ensureGlyphCache();
241 // FIXME: We only support glyphName -> single glyph mapping so far.
242 glyphs.append(m_glyphMap.glyphIdentifierForGlyphName(glyphName));
243 }
244
svgGlyphForGlyph(Glyph glyph)245 SVGGlyph SVGFontElement::svgGlyphForGlyph(Glyph glyph)
246 {
247 ensureGlyphCache();
248 return m_glyphMap.svgGlyphForGlyph(glyph);
249 }
250
missingGlyph()251 Glyph SVGFontElement::missingGlyph()
252 {
253 ensureGlyphCache();
254 return m_missingGlyph;
255 }
256
257 }
258
259 #endif // ENABLE(SVG_FONTS)
260