root/Source/platform/fonts/mac/GlyphPageTreeNodeMac.cpp

DEFINITIONS

1. shouldUseCoreText
2. fill

/*
 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
 *
 * 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE 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 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.
 */

#include "config.h"
#include "platform/fonts/GlyphPageTreeNode.h"

#include <ApplicationServices/ApplicationServices.h>
#include "platform/fonts/Character.h"
#include "platform/fonts/Font.h"
#include "platform/fonts/SimpleFontData.h"

// Forward declare Mac SPIs.
// Request for public API: rdar://13787589
extern "C" {
void CGFontGetGlyphsForUnichars(CGFontRef font, const UniChar chars[], CGGlyph glyphs[], size_t length);
}

namespace WebCore {

static bool shouldUseCoreText(UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
{
    if (fontData->platformData().isCompositeFontReference())
        return true;

    // CoreText doesn't have vertical glyphs of surrogate pair characters.
    // Therefore, we should not use CoreText, but this always returns horizontal glyphs.
    // FIXME: We should use vertical glyphs. https://code.google.com/p/chromium/issues/detail?id=340173
    if (bufferLength >= 2 && U_IS_SURROGATE(buffer[0]) && fontData->hasVerticalGlyphs()) {
        ASSERT(U_IS_SURROGATE_LEAD(buffer[0]));
        ASSERT(U_IS_TRAIL(buffer[1]));
        return false;
    }

    if (fontData->platformData().widthVariant() != RegularWidth || fontData->hasVerticalGlyphs()) {
        // Ideographs don't have a vertical variant or width variants.
        for (unsigned i = 0; i < bufferLength; ++i) {
            if (!Character::isCJKIdeograph(buffer[i]))
                return true;
        }
    }

    return false;
}

bool GlyphPage::fill(unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
{
    bool haveGlyphs = false;

    Vector<CGGlyph, 512> glyphs(bufferLength);
    if (!shouldUseCoreText(buffer, bufferLength, fontData)) {
        CGFontGetGlyphsForUnichars(fontData->platformData().cgFont(), buffer, glyphs.data(), bufferLength);
        for (unsigned i = 0; i < length; ++i) {
            if (!glyphs[i])
                setGlyphDataForIndex(offset + i, 0, 0);
            else {
                setGlyphDataForIndex(offset + i, glyphs[i], fontData);
                haveGlyphs = true;
            }
        }
    } else if (!fontData->platformData().isCompositeFontReference() && fontData->platformData().widthVariant() != RegularWidth
               && CTFontGetGlyphsForCharacters(fontData->platformData().ctFont(), buffer, glyphs.data(), bufferLength)) {
        // When buffer consists of surrogate pairs, CTFontGetGlyphsForCharacters
        // places the glyphs at indices corresponding to the first character of each pair.
        unsigned glyphStep = bufferLength / length;
        for (unsigned i = 0; i < length; ++i) {
            if (!glyphs[i * glyphStep])
                setGlyphDataForIndex(offset + i, 0, 0);
            else {
                setGlyphDataForIndex(offset + i, glyphs[i * glyphStep], fontData);
                haveGlyphs = true;
            }
        }
    } else {
        // We ask CoreText for possible vertical variant glyphs
        RetainPtr<CFStringRef> string(AdoptCF, CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault, buffer, bufferLength, kCFAllocatorNull));
        RetainPtr<CFAttributedStringRef> attributedString(AdoptCF, CFAttributedStringCreate(kCFAllocatorDefault, string.get(), fontData->getCFStringAttributes(0, fontData->hasVerticalGlyphs() ? Vertical : Horizontal)));
        RetainPtr<CTLineRef> line(AdoptCF, CTLineCreateWithAttributedString(attributedString.get()));

        CFArrayRef runArray = CTLineGetGlyphRuns(line.get());
        CFIndex runCount = CFArrayGetCount(runArray);

        // Initialize glyph entries
        for (unsigned index = 0; index < length; ++index)
            setGlyphDataForIndex(offset + index, 0, 0);

        Vector<CGGlyph, 512> glyphVector;
        Vector<CFIndex, 512> indexVector;
        bool done = false;

        // For the CGFont comparison in the loop, use the CGFont that Core Text assigns to the CTFont. This may
        // be non-CFEqual to fontData->platformData().cgFont().
        RetainPtr<CGFontRef> cgFont(AdoptCF, CTFontCopyGraphicsFont(fontData->platformData().ctFont(), 0));

        for (CFIndex r = 0; r < runCount && !done ; ++r) {
            // CTLine could map characters over multiple fonts using its own font fallback list.
            // We need to pick runs that use the exact font we need, i.e., fontData->platformData().ctFont().
            CTRunRef ctRun = static_cast<CTRunRef>(CFArrayGetValueAtIndex(runArray, r));
            ASSERT(CFGetTypeID(ctRun) == CTRunGetTypeID());

            CFDictionaryRef attributes = CTRunGetAttributes(ctRun);
            CTFontRef runFont = static_cast<CTFontRef>(CFDictionaryGetValue(attributes, kCTFontAttributeName));
            RetainPtr<CGFontRef> runCGFont(AdoptCF, CTFontCopyGraphicsFont(runFont, 0));
            // Use CGFont here as CFEqual for CTFont counts all attributes for font.
            bool gotBaseFont = CFEqual(cgFont.get(), runCGFont.get());
            if (gotBaseFont || fontData->platformData().isCompositeFontReference()) {
                // This run uses the font we want. Extract glyphs.
                CFIndex glyphCount = CTRunGetGlyphCount(ctRun);
                const CGGlyph* glyphs = CTRunGetGlyphsPtr(ctRun);
                if (!glyphs) {
                    glyphVector.resize(glyphCount);
                    CTRunGetGlyphs(ctRun, CFRangeMake(0, 0), glyphVector.data());
                    glyphs = glyphVector.data();
                }
                const CFIndex* stringIndices = CTRunGetStringIndicesPtr(ctRun);
                if (!stringIndices) {
                    indexVector.resize(glyphCount);
                    CTRunGetStringIndices(ctRun, CFRangeMake(0, 0), indexVector.data());
                    stringIndices = indexVector.data();
                }

                if (gotBaseFont) {
                    for (CFIndex i = 0; i < glyphCount; ++i) {
                        if (stringIndices[i] >= static_cast<CFIndex>(length)) {
                            done = true;
                            break;
                        }
                        if (glyphs[i]) {
                            setGlyphDataForIndex(offset + stringIndices[i], glyphs[i], fontData);
                            haveGlyphs = true;
                        }
                    }
                } else {
                    const SimpleFontData* runSimple = fontData->getCompositeFontReferenceFontData((NSFont *)runFont);
                    if (runSimple) {
                        for (CFIndex i = 0; i < glyphCount; ++i) {
                            if (stringIndices[i] >= static_cast<CFIndex>(length)) {
                                done = true;
                                break;
                            }
                            if (glyphs[i]) {
                                setGlyphDataForIndex(offset + stringIndices[i], glyphs[i], runSimple);
                                haveGlyphs = true;
                            }
                        }
                    }
                }
            }
        }
    }

    return haveGlyphs;
}

} // namespace WebCore