SimpleFontDataIOS.mm [plain text]
/*
* Copyright (C) 2005, 2006, 2010, 2011 Apple Inc. All rights reserved.
* Copyright (C) 2006 Alexey Proskuryakov
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#import "config.h"
#import "SimpleFontData.h"
#import "BlockExceptions.h"
#import "Font.h"
#import "FontCache.h"
#import "FontDescription.h"
#import "FontServicesIOS.h"
#import <CoreGraphics/CGFontInfo.h>
#import <CoreText/CoreText.h>
#import <float.h>
#import <unicode/uchar.h>
#import <wtf/Assertions.h>
#import <wtf/StdLibExtras.h>
namespace WebCore {
static bool fontFamilyShouldNotBeUsedForArabic(CFStringRef fontFamilyName)
{
if (!fontFamilyName)
return false;
// Times New Roman contains Arabic glyphs, but Core Text doesn't know how to shape them. <rdar://problem/9823975>
// FIXME <rdar://problem/12096835> remove this function once the above bug is fixed.
// Arial and Tahoma are have performance issues so don't use them as well.
return (CFStringCompare(CFSTR("Times New Roman"), fontFamilyName, 0) == kCFCompareEqualTo)
|| (CFStringCompare(CFSTR("Arial"), fontFamilyName, 0) == kCFCompareEqualTo)
|| (CFStringCompare(CFSTR("Tahoma"), fontFamilyName, 0) == kCFCompareEqualTo);
}
static bool fontHasVerticalGlyphs(CTFontRef ctFont)
{
// The check doesn't look neat but this is what AppKit does for vertical writing...
RetainPtr<CFArrayRef> tableTags = adoptCF(CTFontCopyAvailableTables(ctFont, kCTFontTableOptionNoOptions));
CFIndex numTables = CFArrayGetCount(tableTags.get());
for (CFIndex index = 0; index < numTables; ++index) {
CTFontTableTag tag = (CTFontTableTag)(uintptr_t)CFArrayGetValueAtIndex(tableTags.get(), index);
if (tag == kCTFontTableVhea || tag == kCTFontTableVORG)
return true;
}
return false;
}
void SimpleFontData::platformInit()
{
m_syntheticBoldOffset = m_platformData.m_syntheticBold ? ceilf(m_platformData.size() / 24.0f) : 0.f;
m_spaceGlyph = 0;
m_spaceWidth = 0;
unsigned unitsPerEm;
float ascent;
float descent;
float lineGap;
float lineSpacing;
float xHeight;
RetainPtr<CFStringRef> familyName;
if (CTFontRef ctFont = m_platformData.font()) {
FontServicesIOS fontService(ctFont);
ascent = ceilf(fontService.ascent());
descent = ceilf(fontService.descent());
lineSpacing = fontService.lineSpacing();
lineGap = fontService.lineGap();
xHeight = fontService.xHeight();
unitsPerEm = fontService.unitsPerEm();
familyName = adoptCF(CTFontCopyFamilyName(ctFont));
} else {
CGFontRef cgFont = m_platformData.cgFont();
unitsPerEm = CGFontGetUnitsPerEm(cgFont);
float pointSize = m_platformData.size();
ascent = lroundf(scaleEmToUnits(CGFontGetAscent(cgFont), unitsPerEm) * pointSize);
descent = lroundf(-scaleEmToUnits(-abs(CGFontGetDescent(cgFont)), unitsPerEm) * pointSize);
lineGap = lroundf(scaleEmToUnits(CGFontGetLeading(cgFont), unitsPerEm) * pointSize);
xHeight = scaleEmToUnits(CGFontGetXHeight(cgFont), unitsPerEm) * pointSize;
lineSpacing = ascent + descent + lineGap;
familyName = adoptCF(CGFontCopyFamilyName(cgFont));
}
m_fontMetrics.setUnitsPerEm(unitsPerEm);
m_fontMetrics.setAscent(ascent);
m_fontMetrics.setDescent(descent);
m_fontMetrics.setLineGap(lineGap);
m_fontMetrics.setLineSpacing(lineSpacing);
m_fontMetrics.setXHeight(xHeight);
m_shouldNotBeUsedForArabic = fontFamilyShouldNotBeUsedForArabic(familyName.get());
if (platformData().orientation() == Vertical && !isTextOrientationFallback())
m_hasVerticalGlyphs = fontHasVerticalGlyphs(m_platformData.ctFont());
if (!m_platformData.m_isEmoji)
return;
int thirdOfSize = m_platformData.size() / 3;
m_fontMetrics.setAscent(thirdOfSize);
m_fontMetrics.setDescent(thirdOfSize);
m_fontMetrics.setLineGap(thirdOfSize);
m_fontMetrics.setLineSpacing(0);
}
void SimpleFontData::platformCharWidthInit()
{
m_avgCharWidth = 0;
m_maxCharWidth = 0;
// Fallback to a cross-platform estimate, which will populate these values if they are non-positive.
initCharWidths();
}
PassRefPtr<SimpleFontData> SimpleFontData::platformCreateScaledFontData(const FontDescription&, float scaleFactor) const
{
if (isCustomFont()) {
FontPlatformData scaledFontData(m_platformData);
scaledFontData.m_size = scaledFontData.m_size * scaleFactor;
return SimpleFontData::create(scaledFontData, true, false);
}
float size = m_platformData.size() * scaleFactor;
CTFontSymbolicTraits fontTraits = CTFontGetSymbolicTraits(m_platformData.font());
RetainPtr<CTFontDescriptorRef> fontDescriptor = adoptCF(CTFontCopyFontDescriptor(m_platformData.font()));
RetainPtr<CTFontRef> scaledFont = adoptCF(CTFontCreateWithFontDescriptor(fontDescriptor.get(), size, nullptr));
FontPlatformData scaledFontData(scaledFont.get(), size, m_platformData.isPrinterFont(), false, false, m_platformData.orientation());
if (scaledFontData.font()) {
if (m_platformData.m_syntheticBold)
fontTraits |= kCTFontBoldTrait;
if (m_platformData.m_syntheticOblique)
fontTraits |= kCTFontItalicTrait;
CTFontSymbolicTraits scaledFontTraits = CTFontGetSymbolicTraits(scaledFontData.font());
scaledFontData.m_syntheticBold = (fontTraits & kCTFontBoldTrait) && !(scaledFontTraits & kCTFontTraitBold);
scaledFontData.m_syntheticOblique = (fontTraits & kCTFontItalicTrait) && !(scaledFontTraits & kCTFontTraitItalic);
return fontCache().getCachedFontData(&scaledFontData);
}
return nullptr;
}
bool SimpleFontData::containsCharacters(const UChar*, int) const
{
return false;
}
void SimpleFontData::determinePitch()
{
CTFontRef ctFont = m_platformData.font();
m_treatAsFixedPitch = false;
if (!ctFont)
return; // CTFont is null in the case of SVG fonts for example.
RetainPtr<CFStringRef> fullName = adoptCF(CTFontCopyFullName(ctFont));
RetainPtr<CFStringRef> familyName = adoptCF(CTFontCopyFamilyName(ctFont));
m_treatAsFixedPitch = CGFontIsFixedPitch(m_platformData.cgFont()) || (fullName && (CFStringCompare(fullName.get(), CFSTR("Osaka-Mono"), kCFCompareCaseInsensitive) == kCFCompareEqualTo || CFStringCompare(fullName.get(), CFSTR("MS-PGothic"), kCFCompareCaseInsensitive) == kCFCompareEqualTo));
if (familyName && CFStringCompare(familyName.get(), CFSTR("Courier New"), kCFCompareCaseInsensitive) == kCFCompareEqualTo) {
// Special case Courier New to not be treated as fixed pitch, as this will make use of a hacked space width which is undesireable for iPhone (see rdar://6269783).
m_treatAsFixedPitch = false;
}
}
CGFontRenderingStyle SimpleFontData::renderingStyle() const
{
return kCGFontRenderingStyleAntialiasing | kCGFontRenderingStyleSubpixelPositioning | kCGFontRenderingStyleSubpixelQuantization | kCGFontAntialiasingStyleUnfiltered;
}
bool SimpleFontData::advanceForColorBitmapFont(Glyph, CGSize&) const
{
return false;
}
} // namespace WebCore