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/*
* Copyright (C) 2008 Alp Toker <alp@atoker.com>
* Copyright (C) 2010 Igalia S.L.
*
* 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"
#include "FontCache.h"
#include "Font.h"
#include "OwnPtrCairo.h"
#include "RefPtrCairo.h"
#include "SimpleFontData.h"
#include <cairo-ft.h>
#include <cairo.h>
#include <fontconfig/fcfreetype.h>
#include <wtf/Assertions.h>
#include <wtf/text/CString.h>
namespace WebCore {
void FontCache::platformInit()
{
// It's fine to call FcInit multiple times per the documentation.
if (!FcInit())
ASSERT_NOT_REACHED();
}
FcPattern* createFontConfigPatternForCharacters(const UChar* characters, int length)
{
FcPattern* pattern = FcPatternCreate();
FcCharSet* fontConfigCharSet = FcCharSetCreate();
for (int i = 0; i < length; ++i) {
if (U16_IS_SURROGATE(characters[i]) && U16_IS_SURROGATE_LEAD(characters[i])
&& i != length - 1 && U16_IS_TRAIL(characters[i + 1])) {
FcCharSetAddChar(fontConfigCharSet, U16_GET_SUPPLEMENTARY(characters[i], characters[i+1]));
i++;
} else
FcCharSetAddChar(fontConfigCharSet, characters[i]);
}
FcPatternAddCharSet(pattern, FC_CHARSET, fontConfigCharSet);
FcCharSetDestroy(fontConfigCharSet);
FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
FcConfigSubstitute(0, pattern, FcMatchPattern);
FcDefaultSubstitute(pattern);
return pattern;
}
FcPattern* findBestFontGivenFallbacks(const FontPlatformData& fontData, FcPattern* pattern)
{
if (!fontData.m_pattern)
return 0;
if (!fontData.m_fallbacks) {
FcResult fontConfigResult;
fontData.m_fallbacks = FcFontSort(0, fontData.m_pattern.get(), FcTrue, 0, &fontConfigResult);
}
if (!fontData.m_fallbacks)
return 0;
FcFontSet* sets[] = { fontData.m_fallbacks };
FcResult fontConfigResult;
return FcFontSetMatch(0, sets, 1, pattern, &fontConfigResult);
}
const SimpleFontData* FontCache::getFontDataForCharacters(const Font& font, const UChar* characters, int length)
{
RefPtr<FcPattern> pattern = adoptRef(createFontConfigPatternForCharacters(characters, length));
const FontPlatformData& fontData = font.primaryFont()->platformData();
RefPtr<FcPattern> fallbackPattern = adoptRef(findBestFontGivenFallbacks(fontData, pattern.get()));
if (fallbackPattern) {
FontPlatformData alternateFontData(fallbackPattern.get(), font.fontDescription());
return getCachedFontData(&alternateFontData, DoNotRetain);
}
FcResult fontConfigResult;
RefPtr<FcPattern> resultPattern = adoptRef(FcFontMatch(0, pattern.get(), &fontConfigResult));
if (!resultPattern)
return 0;
FontPlatformData alternateFontData(resultPattern.get(), font.fontDescription());
return getCachedFontData(&alternateFontData, DoNotRetain);
}
SimpleFontData* FontCache::getSimilarFontPlatformData(const Font&)
{
return 0;
}
SimpleFontData* FontCache::getLastResortFallbackFont(const FontDescription& fontDescription, ShouldRetain shouldRetain)
{
// We want to return a fallback font here, otherwise the logic preventing FontConfig
// matches for non-fallback fonts might return 0. See isFallbackFontAllowed.
static AtomicString timesStr("serif");
return getCachedFontData(fontDescription, timesStr, false, shouldRetain);
}
void FontCache::getTraitsInFamily(const AtomicString&, Vector<unsigned>&)
{
}
static String getFamilyNameStringFromFontDescriptionAndFamily(const FontDescription& fontDescription, const AtomicString& family)
{
// If we're creating a fallback font (e.g. "-webkit-monospace"), convert the name into
// the fallback name (like "monospace") that fontconfig understands.
if (family.length() && !family.startsWith("-webkit-"))
return family.string();
switch (fontDescription.genericFamily()) {
case FontDescription::StandardFamily:
case FontDescription::SerifFamily:
return "serif";
case FontDescription::SansSerifFamily:
return "sans-serif";
case FontDescription::MonospaceFamily:
return "monospace";
case FontDescription::CursiveFamily:
return "cursive";
case FontDescription::FantasyFamily:
return "fantasy";
case FontDescription::NoFamily:
default:
return "";
}
}
int fontWeightToFontconfigWeight(FontWeight weight)
{
switch (weight) {
case FontWeight100:
return FC_WEIGHT_THIN;
case FontWeight200:
return FC_WEIGHT_ULTRALIGHT;
case FontWeight300:
return FC_WEIGHT_LIGHT;
case FontWeight400:
return FC_WEIGHT_REGULAR;
case FontWeight500:
return FC_WEIGHT_MEDIUM;
case FontWeight600:
return FC_WEIGHT_SEMIBOLD;
case FontWeight700:
return FC_WEIGHT_BOLD;
case FontWeight800:
return FC_WEIGHT_EXTRABOLD;
case FontWeight900:
return FC_WEIGHT_ULTRABLACK;
default:
ASSERT_NOT_REACHED();
return FC_WEIGHT_REGULAR;
}
}
FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const AtomicString& family)
{
// The CSS font matching algorithm (http://www.w3.org/TR/css3-fonts/#font-matching-algorithm)
// says that we must find an exact match for font family, slant (italic or oblique can be used)
// and font weight (we only match bold/non-bold here).
RefPtr<FcPattern> pattern = adoptRef(FcPatternCreate());
String familyNameString(getFamilyNameStringFromFontDescriptionAndFamily(fontDescription, family));
if (!FcPatternAddString(pattern.get(), FC_FAMILY, reinterpret_cast<const FcChar8*>(familyNameString.utf8().data())))
return 0;
bool italic = fontDescription.italic();
if (!FcPatternAddInteger(pattern.get(), FC_SLANT, italic ? FC_SLANT_ITALIC : FC_SLANT_ROMAN))
return 0;
if (!FcPatternAddInteger(pattern.get(), FC_WEIGHT, fontWeightToFontconfigWeight(fontDescription.weight())))
return 0;
if (!FcPatternAddDouble(pattern.get(), FC_PIXEL_SIZE, fontDescription.computedPixelSize()))
return 0;
// The strategy is originally from Skia (src/ports/SkFontHost_fontconfig.cpp):
// Allow Fontconfig to do pre-match substitution. Unless we are accessing a "fallback"
// family like "sans," this is the only time we allow Fontconfig to substitute one
// family name for another (i.e. if the fonts are aliased to each other).
FcConfigSubstitute(0, pattern.get(), FcMatchPattern);
FcDefaultSubstitute(pattern.get());
FcChar8* fontConfigFamilyNameAfterConfiguration;
FcPatternGetString(pattern.get(), FC_FAMILY, 0, &fontConfigFamilyNameAfterConfiguration);
String familyNameAfterConfiguration = String::fromUTF8(reinterpret_cast<char*>(fontConfigFamilyNameAfterConfiguration));
FcResult fontConfigResult;
RefPtr<FcPattern> resultPattern = adoptRef(FcFontMatch(0, pattern.get(), &fontConfigResult));
if (!resultPattern) // No match.
return 0;
FcChar8* fontConfigFamilyNameAfterMatching;
FcPatternGetString(resultPattern.get(), FC_FAMILY, 0, &fontConfigFamilyNameAfterMatching);
String familyNameAfterMatching = String::fromUTF8(reinterpret_cast<char*>(fontConfigFamilyNameAfterMatching));
// If Fontconfig gave use a different font family than the one we requested, we should ignore it
// and allow WebCore to give us the next font on the CSS fallback list. The only exception is if
// this family name is a commonly used generic family.
if (!equalIgnoringCase(familyNameAfterConfiguration, familyNameAfterMatching)
&& !(equalIgnoringCase(familyNameString, "sans") || equalIgnoringCase(familyNameString, "sans-serif")
|| equalIgnoringCase(familyNameString, "serif") || equalIgnoringCase(familyNameString, "monospace")
|| equalIgnoringCase(familyNameString, "fantasy") || equalIgnoringCase(familyNameString, "cursive")))
return 0;
// Verify that this font has an encoding compatible with Fontconfig. Fontconfig currently
// supports three encodings in FcFreeTypeCharIndex: Unicode, Symbol and AppleRoman.
// If this font doesn't have one of these three encodings, don't select it.
FontPlatformData* platformData = new FontPlatformData(resultPattern.get(), fontDescription);
if (!platformData->hasCompatibleCharmap()) {
delete platformData;
return 0;
}
return platformData;
}
}
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