Source/WebCore/svg/SVGFontElement.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) Research In Motion Limited 2010. 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"

 #if ENABLE(SVG_FONTS)
 #include "SVGFontElement.h"

 #include "Document.h"
 #include "ElementIterator.h"
 #include "FontCascade.h"
 #include "SVGGlyphElement.h"
 #include "SVGHKernElement.h"
 #include "SVGMissingGlyphElement.h"
 #include "SVGNames.h"
 #include "SVGVKernElement.h"
 #include <wtf/ASCIICType.h>

 namespace WebCore {

 // Animated property definitions
 DEFINE_ANIMATED_BOOLEAN(SVGFontElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)

 BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGFontElement)
     REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
     REGISTER_PARENT_ANIMATED_PROPERTIES(SVGElement)
 END_REGISTER_ANIMATED_PROPERTIES

 inline SVGFontElement::SVGFontElement(const QualifiedName& tagName, Document& document)
     : SVGElement(tagName, document)
     , m_missingGlyph(0)
     , m_isGlyphCacheValid(false)
 {
     ASSERT(hasTagName(SVGNames::fontTag));
     registerAnimatedPropertiesForSVGFontElement();
 }

 Ref<SVGFontElement> SVGFontElement::create(const QualifiedName& tagName, Document& document)
 {
     return adoptRef(*new SVGFontElement(tagName, document));
 }

 void SVGFontElement::invalidateGlyphCache()
 {
     if (m_isGlyphCacheValid) {
         m_glyphMap.clear();
         m_horizontalKerningMap.clear();
         m_verticalKerningMap.clear();
     }
     m_isGlyphCacheValid = false;
 }

 const SVGMissingGlyphElement* SVGFontElement::firstMissingGlyphElement() const
 {
     return childrenOfType<SVGMissingGlyphElement>(*this).first();
 }

 void SVGFontElement::registerLigaturesInGlyphCache(Vector<String>& ligatures)
 {
     ASSERT(!ligatures.isEmpty());

     // Register each character of a ligature in the map, if not present.
     // Eg. If only a "fi" ligature is present, but not "f" and "i", the
     // GlyphPage will not contain any entries for "f" and "i", so the
     // SVGFont is not used to render the text "fi1234". Register an
     // empty SVGGlyph with the character, so the SVG Font will be used
     // to render the text. If someone tries to render "f2" the SVG Font
     // will not be able to find a glyph for "f", but handles the fallback
     // character substitution properly through glyphDataForCharacter().
     Vector<SVGGlyph> glyphs;
     for (auto& unicode : ligatures) {
         unsigned unicodeLength = unicode.length();
         ASSERT(unicodeLength > 1);

         for (unsigned i = 0; i < unicodeLength; ++i) {
             UChar character = unicode[i];
             String lookupString(&character, 1);
             m_glyphMap.collectGlyphsForString(lookupString, glyphs);
             if (!glyphs.isEmpty()) {
                 glyphs.clear();
                 continue;
             }

             // This glyph is never meant to be used for rendering, only as identifier as a part of a ligature.
             SVGGlyph newGlyphPart;
             newGlyphPart.isPartOfLigature = true;
             m_glyphMap.addGlyph(String(), lookupString, newGlyphPart);
         }
     }
 }

 void SVGFontElement::ensureGlyphCache()
 {
     if (m_isGlyphCacheValid)
         return;

     const SVGMissingGlyphElement* firstMissingGlyphElement = nullptr;
     Vector<String> ligatures;
     for (auto& child : childrenOfType<SVGElement>(*this)) {
         if (is<SVGGlyphElement>(child)) {
             SVGGlyphElement& glyph = downcast<SVGGlyphElement>(child);
             AtomicString unicode = glyph.fastGetAttribute(SVGNames::unicodeAttr);
             AtomicString glyphId = glyph.getIdAttribute();
             if (glyphId.isEmpty() && unicode.isEmpty())
                 continue;

             m_glyphMap.addGlyph(glyphId, unicode, glyph.buildGlyphIdentifier());

             // Register ligatures, if needed, don't mix up with surrogate pairs though!
             if (unicode.length() > 1 && !U16_IS_SURROGATE(unicode[0]))
                 ligatures.append(unicode.string());
         } else if (is<SVGHKernElement>(child)) {
             SVGHKernElement& hkern = downcast<SVGHKernElement>(child);
             SVGKerningPair kerningPair;
             if (hkern.buildHorizontalKerningPair(kerningPair))
                 m_horizontalKerningMap.insert(kerningPair);
         } else if (is<SVGVKernElement>(child)) {
             SVGVKernElement& vkern = downcast<SVGVKernElement>(child);
             SVGKerningPair kerningPair;
             if (vkern.buildVerticalKerningPair(kerningPair))
                 m_verticalKerningMap.insert(kerningPair);
         } else if (is<SVGMissingGlyphElement>(child) && !firstMissingGlyphElement)
             firstMissingGlyphElement = &downcast<SVGMissingGlyphElement>(child);
     }

     // Register each character of each ligature, if needed.
     if (!ligatures.isEmpty())
         registerLigaturesInGlyphCache(ligatures);

     // Register missing-glyph element, if present.
     if (firstMissingGlyphElement) {
         SVGGlyph svgGlyph = SVGGlyphElement::buildGenericGlyphIdentifier(firstMissingGlyphElement);
         m_glyphMap.appendToGlyphTable(svgGlyph);
         m_missingGlyph = svgGlyph.tableEntry;
         ASSERT(m_missingGlyph > 0);
     }

     m_isGlyphCacheValid = true;
 }

 void SVGKerningMap::clear()
 {
     unicodeMap.clear();
     glyphMap.clear();
     kerningUnicodeRangeMap.clear();
 }

 void SVGKerningMap::insert(const SVGKerningPair& kerningPair)
 {
     SVGKerning svgKerning;
     svgKerning.kerning = kerningPair.kerning;
     svgKerning.unicodeRange2 = kerningPair.unicodeRange2;
     svgKerning.unicodeName2 = kerningPair.unicodeName2;
     svgKerning.glyphName2 = kerningPair.glyphName2;

     for (auto& name : kerningPair.unicodeName1) {
         if (unicodeMap.contains(name))
             unicodeMap.get(name)->append(svgKerning);
         else {
             auto newVector = std::make_unique<SVGKerningVector>();
             newVector->append(svgKerning);
             unicodeMap.add(name, WTF::move(newVector));
         }
     }

     for (auto& name : kerningPair.glyphName1) {
         if (glyphMap.contains(name))
             glyphMap.get(name)->append(svgKerning);
         else {
             auto newVector = std::make_unique<SVGKerningVector>();
             newVector->append(svgKerning);
             glyphMap.add(name, WTF::move(newVector));
         }
     }

     if (!kerningPair.unicodeRange1.isEmpty())
         kerningUnicodeRangeMap.append(kerningPair);
 }

 static inline bool stringMatchesUnicodeRange(const String& unicodeString, const UnicodeRanges& ranges)
 {
     if (unicodeString.isEmpty())
         return false;

     if (!ranges.isEmpty()) {
         UChar firstChar = unicodeString[0];
         for (auto& range : ranges) {
             if (firstChar >= range.first && firstChar <= range.second)
                 return true;
         }
     }

     return false;
 }

 static inline bool stringMatchesGlyphName(const String& glyphName, const HashSet<String>& glyphValues)
 {
     if (glyphName.isEmpty())
         return false;

     return glyphValues.contains(glyphName);
 }

 static inline bool stringMatchesUnicodeName(const String& unicodeName, const HashSet<String>& unicodeValues)
 {
     if (unicodeName.isEmpty())
         return false;

     return unicodeValues.contains(unicodeName);
 }

 static inline bool matches(const String& u2, const String& g2, const SVGKerning& svgKerning)
 {
     return stringMatchesGlyphName(g2, svgKerning.glyphName2)
         || stringMatchesUnicodeName(u2, svgKerning.unicodeName2)
         || stringMatchesUnicodeRange(u2, svgKerning.unicodeRange2);
 }

 static inline bool matches(const String& u1, const String& u2, const String& g2, const SVGKerningPair& svgKerningPair)
 {
     return stringMatchesUnicodeRange(u1, svgKerningPair.unicodeRange1) && matches(u2, g2, svgKerningPair);
 }

 static inline float kerningForPairOfStringsAndGlyphs(const SVGKerningMap& kerningMap, const String& u1, const String& g1, const String& u2, const String& g2)
 {
     if (!g1.isEmpty() && kerningMap.glyphMap.contains(g1)) {
         SVGKerningVector* kerningVector = kerningMap.glyphMap.get(g1);
         SVGKerningVector::const_iterator it = kerningVector->end() - 1;
         const SVGKerningVector::const_iterator begin = kerningVector->begin() - 1;
         for (; it != begin; --it) {
             if (matches(u2, g2, *it))
                 return it->kerning;
         }
     }

     if (!u1.isEmpty()) {
         if (kerningMap.unicodeMap.contains(u1)) {
             SVGKerningVector* kerningVector = kerningMap.unicodeMap.get(u1);
             SVGKerningVector::const_iterator it = kerningVector->end() - 1;
             const SVGKerningVector::const_iterator begin = kerningVector->begin() - 1;
             for (; it != begin; --it) {
                 if (matches(u2, g2, *it))
                     return it->kerning;
             }
         }

         if (!kerningMap.kerningUnicodeRangeMap.isEmpty()) {
             Vector<SVGKerningPair>::const_iterator it = kerningMap.kerningUnicodeRangeMap.end() - 1;
             const Vector<SVGKerningPair>::const_iterator begin = kerningMap.kerningUnicodeRangeMap.begin() - 1;
             for (; it != begin; --it) {
                 if (matches(u1, u2, g2, *it))
                     return it->kerning;
             }
         }
     }

     return 0;
 }

 float SVGFontElement::horizontalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
 {
     if (m_horizontalKerningMap.isEmpty())
         return 0;

     return kerningForPairOfStringsAndGlyphs(m_horizontalKerningMap, u1, g1, u2, g2);
 }

 float SVGFontElement::verticalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
 {
     if (m_verticalKerningMap.isEmpty())
         return 0;

     return kerningForPairOfStringsAndGlyphs(m_verticalKerningMap, u1, g1, u2, g2);
 }

 void SVGFontElement::collectGlyphsForString(const String& string, Vector<SVGGlyph>& glyphs)
 {
     ensureGlyphCache();
     m_glyphMap.collectGlyphsForString(string, glyphs);
 }

 void SVGFontElement::collectGlyphsForGlyphName(const String& glyphName, Vector<SVGGlyph>& glyphs)
 {
     ensureGlyphCache();
     // FIXME: We only support glyphName -> single glyph mapping so far.
     glyphs.append(m_glyphMap.glyphIdentifierForGlyphName(glyphName));
 }

 SVGGlyph SVGFontElement::svgGlyphForGlyph(Glyph glyph)
 {
     ensureGlyphCache();
     return m_glyphMap.svgGlyphForGlyph(glyph);
 }

 Glyph SVGFontElement::missingGlyph()
 {
     ensureGlyphCache();
     return m_missingGlyph;
 }

 }

 #endif // ENABLE(SVG_FONTS)
	/*
	* Copyright (C) 2007 Eric Seidel <eric@webkit.org>
	* Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
	* Copyright (C) Research In Motion Limited 2010. 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"

	#if ENABLE(SVG_FONTS)
	#include "SVGFontElement.h"

	#include "Document.h"
	#include "ElementIterator.h"
	#include "FontCascade.h"
	#include "SVGGlyphElement.h"
	#include "SVGHKernElement.h"
	#include "SVGMissingGlyphElement.h"
	#include "SVGNames.h"
	#include "SVGVKernElement.h"
	#include <wtf/ASCIICType.h>

	namespace WebCore {

	// Animated property definitions
	DEFINE_ANIMATED_BOOLEAN(SVGFontElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)

	BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGFontElement)
	REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
	REGISTER_PARENT_ANIMATED_PROPERTIES(SVGElement)
	END_REGISTER_ANIMATED_PROPERTIES

	inline SVGFontElement::SVGFontElement(const QualifiedName& tagName, Document& document)
	: SVGElement(tagName, document)
	, m_missingGlyph(0)
	, m_isGlyphCacheValid(false)
	{
	ASSERT(hasTagName(SVGNames::fontTag));
	registerAnimatedPropertiesForSVGFontElement();
	}

	Ref<SVGFontElement> SVGFontElement::create(const QualifiedName& tagName, Document& document)
	{
	return adoptRef(*new SVGFontElement(tagName, document));
	}

	void SVGFontElement::invalidateGlyphCache()
	{
	if (m_isGlyphCacheValid) {
	m_glyphMap.clear();
	m_horizontalKerningMap.clear();
	m_verticalKerningMap.clear();
	}
	m_isGlyphCacheValid = false;
	}

	const SVGMissingGlyphElement* SVGFontElement::firstMissingGlyphElement() const
	{
	return childrenOfType<SVGMissingGlyphElement>(*this).first();
	}

	void SVGFontElement::registerLigaturesInGlyphCache(Vector<String>& ligatures)
	{
	ASSERT(!ligatures.isEmpty());

	// Register each character of a ligature in the map, if not present.
	// Eg. If only a "fi" ligature is present, but not "f" and "i", the
	// GlyphPage will not contain any entries for "f" and "i", so the
	// SVGFont is not used to render the text "fi1234". Register an
	// empty SVGGlyph with the character, so the SVG Font will be used
	// to render the text. If someone tries to render "f2" the SVG Font
	// will not be able to find a glyph for "f", but handles the fallback
	// character substitution properly through glyphDataForCharacter().
	Vector<SVGGlyph> glyphs;
	for (auto& unicode : ligatures) {
	unsigned unicodeLength = unicode.length();
	ASSERT(unicodeLength > 1);

	for (unsigned i = 0; i < unicodeLength; ++i) {
	UChar character = unicode[i];
	String lookupString(&character, 1);
	m_glyphMap.collectGlyphsForString(lookupString, glyphs);
	if (!glyphs.isEmpty()) {
	glyphs.clear();
	continue;
	}

	// This glyph is never meant to be used for rendering, only as identifier as a part of a ligature.
	SVGGlyph newGlyphPart;
	newGlyphPart.isPartOfLigature = true;
	m_glyphMap.addGlyph(String(), lookupString, newGlyphPart);
	}
	}
	}

	void SVGFontElement::ensureGlyphCache()
	{
	if (m_isGlyphCacheValid)
	return;

	const SVGMissingGlyphElement* firstMissingGlyphElement = nullptr;
	Vector<String> ligatures;
	for (auto& child : childrenOfType<SVGElement>(*this)) {
	if (is<SVGGlyphElement>(child)) {
	SVGGlyphElement& glyph = downcast<SVGGlyphElement>(child);
	AtomicString unicode = glyph.fastGetAttribute(SVGNames::unicodeAttr);
	AtomicString glyphId = glyph.getIdAttribute();
	if (glyphId.isEmpty() && unicode.isEmpty())
	continue;

	m_glyphMap.addGlyph(glyphId, unicode, glyph.buildGlyphIdentifier());

	// Register ligatures, if needed, don't mix up with surrogate pairs though!
	if (unicode.length() > 1 && !U16_IS_SURROGATE(unicode[0]))
	ligatures.append(unicode.string());
	} else if (is<SVGHKernElement>(child)) {
	SVGHKernElement& hkern = downcast<SVGHKernElement>(child);
	SVGKerningPair kerningPair;
	if (hkern.buildHorizontalKerningPair(kerningPair))
	m_horizontalKerningMap.insert(kerningPair);
	} else if (is<SVGVKernElement>(child)) {
	SVGVKernElement& vkern = downcast<SVGVKernElement>(child);
	SVGKerningPair kerningPair;
	if (vkern.buildVerticalKerningPair(kerningPair))
	m_verticalKerningMap.insert(kerningPair);
	} else if (is<SVGMissingGlyphElement>(child) && !firstMissingGlyphElement)
	firstMissingGlyphElement = &downcast<SVGMissingGlyphElement>(child);
	}

	// Register each character of each ligature, if needed.
	if (!ligatures.isEmpty())
	registerLigaturesInGlyphCache(ligatures);

	// Register missing-glyph element, if present.
	if (firstMissingGlyphElement) {
	SVGGlyph svgGlyph = SVGGlyphElement::buildGenericGlyphIdentifier(firstMissingGlyphElement);
	m_glyphMap.appendToGlyphTable(svgGlyph);
	m_missingGlyph = svgGlyph.tableEntry;
	ASSERT(m_missingGlyph > 0);
	}

	m_isGlyphCacheValid = true;
	}

	void SVGKerningMap::clear()
	{
	unicodeMap.clear();
	glyphMap.clear();
	kerningUnicodeRangeMap.clear();
	}

	void SVGKerningMap::insert(const SVGKerningPair& kerningPair)
	{
	SVGKerning svgKerning;
	svgKerning.kerning = kerningPair.kerning;
	svgKerning.unicodeRange2 = kerningPair.unicodeRange2;
	svgKerning.unicodeName2 = kerningPair.unicodeName2;
	svgKerning.glyphName2 = kerningPair.glyphName2;

	for (auto& name : kerningPair.unicodeName1) {
	if (unicodeMap.contains(name))
	unicodeMap.get(name)->append(svgKerning);
	else {
	auto newVector = std::make_unique<SVGKerningVector>();
	newVector->append(svgKerning);
	unicodeMap.add(name, WTF::move(newVector));
	}
	}

	for (auto& name : kerningPair.glyphName1) {
	if (glyphMap.contains(name))
	glyphMap.get(name)->append(svgKerning);
	else {
	auto newVector = std::make_unique<SVGKerningVector>();
	newVector->append(svgKerning);
	glyphMap.add(name, WTF::move(newVector));
	}
	}

	if (!kerningPair.unicodeRange1.isEmpty())
	kerningUnicodeRangeMap.append(kerningPair);
	}

	static inline bool stringMatchesUnicodeRange(const String& unicodeString, const UnicodeRanges& ranges)
	{
	if (unicodeString.isEmpty())
	return false;

	if (!ranges.isEmpty()) {
	UChar firstChar = unicodeString[0];
	for (auto& range : ranges) {
	if (firstChar >= range.first && firstChar <= range.second)
	return true;
	}
	}

	return false;
	}

	static inline bool stringMatchesGlyphName(const String& glyphName, const HashSet<String>& glyphValues)
	{
	if (glyphName.isEmpty())
	return false;

	return glyphValues.contains(glyphName);
	}

	static inline bool stringMatchesUnicodeName(const String& unicodeName, const HashSet<String>& unicodeValues)
	{
	if (unicodeName.isEmpty())
	return false;

	return unicodeValues.contains(unicodeName);
	}

	static inline bool matches(const String& u2, const String& g2, const SVGKerning& svgKerning)
	{
	return stringMatchesGlyphName(g2, svgKerning.glyphName2)
	\|\| stringMatchesUnicodeName(u2, svgKerning.unicodeName2)
	\|\| stringMatchesUnicodeRange(u2, svgKerning.unicodeRange2);
	}

	static inline bool matches(const String& u1, const String& u2, const String& g2, const SVGKerningPair& svgKerningPair)
	{
	return stringMatchesUnicodeRange(u1, svgKerningPair.unicodeRange1) && matches(u2, g2, svgKerningPair);
	}

	static inline float kerningForPairOfStringsAndGlyphs(const SVGKerningMap& kerningMap, const String& u1, const String& g1, const String& u2, const String& g2)
	{
	if (!g1.isEmpty() && kerningMap.glyphMap.contains(g1)) {
	SVGKerningVector* kerningVector = kerningMap.glyphMap.get(g1);
	SVGKerningVector::const_iterator it = kerningVector->end() - 1;
	const SVGKerningVector::const_iterator begin = kerningVector->begin() - 1;
	for (; it != begin; --it) {
	if (matches(u2, g2, *it))
	return it->kerning;
	}
	}

	if (!u1.isEmpty()) {
	if (kerningMap.unicodeMap.contains(u1)) {
	SVGKerningVector* kerningVector = kerningMap.unicodeMap.get(u1);
	SVGKerningVector::const_iterator it = kerningVector->end() - 1;
	const SVGKerningVector::const_iterator begin = kerningVector->begin() - 1;
	for (; it != begin; --it) {
	if (matches(u2, g2, *it))
	return it->kerning;
	}
	}

	if (!kerningMap.kerningUnicodeRangeMap.isEmpty()) {
	Vector<SVGKerningPair>::const_iterator it = kerningMap.kerningUnicodeRangeMap.end() - 1;
	const Vector<SVGKerningPair>::const_iterator begin = kerningMap.kerningUnicodeRangeMap.begin() - 1;
	for (; it != begin; --it) {
	if (matches(u1, u2, g2, *it))
	return it->kerning;
	}
	}
	}

	return 0;
	}

	float SVGFontElement::horizontalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
	{
	if (m_horizontalKerningMap.isEmpty())
	return 0;

	return kerningForPairOfStringsAndGlyphs(m_horizontalKerningMap, u1, g1, u2, g2);
	}

	float SVGFontElement::verticalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const
	{
	if (m_verticalKerningMap.isEmpty())
	return 0;

	return kerningForPairOfStringsAndGlyphs(m_verticalKerningMap, u1, g1, u2, g2);
	}

	void SVGFontElement::collectGlyphsForString(const String& string, Vector<SVGGlyph>& glyphs)
	{
	ensureGlyphCache();
	m_glyphMap.collectGlyphsForString(string, glyphs);
	}

	void SVGFontElement::collectGlyphsForGlyphName(const String& glyphName, Vector<SVGGlyph>& glyphs)
	{
	ensureGlyphCache();
	// FIXME: We only support glyphName -> single glyph mapping so far.
	glyphs.append(m_glyphMap.glyphIdentifierForGlyphName(glyphName));
	}

	SVGGlyph SVGFontElement::svgGlyphForGlyph(Glyph glyph)
	{
	ensureGlyphCache();
	return m_glyphMap.svgGlyphForGlyph(glyph);
	}

	Glyph SVGFontElement::missingGlyph()
	{
	ensureGlyphCache();
	return m_missingGlyph;
	}

	}

	#endif // ENABLE(SVG_FONTS)