Source/core/css/CSSSegmentedFontFace.cpp

/*
 * Copyright (C) 2008 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
 * 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
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#include "config.h"
#include "core/css/CSSSegmentedFontFace.h"

#include "RuntimeEnabledFeatures.h"
#include "core/css/CSSFontFace.h"
#include "core/css/CSSFontSelector.h"
#include "platform/fonts/FontCache.h"
#include "platform/fonts/FontDescription.h"
#include "platform/fonts/SegmentedFontData.h"
#include "platform/fonts/SimpleFontData.h"

namespace WebCore {

CSSSegmentedFontFace::CSSSegmentedFontFace(CSSFontSelector* fontSelector, FontTraitsMask traitsMask)
    : m_fontSelector(fontSelector)
    , m_traitsMask(traitsMask)
    , m_firstNonCssConnectedFace(m_fontFaces.end())
{
}

CSSSegmentedFontFace::~CSSSegmentedFontFace()
{
    pruneTable();
    for (FontFaceList::iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it)
        (*it)->cssFontFace()->clearSegmentedFontFace();
}

void CSSSegmentedFontFace::pruneTable()
{
    // Make sure the glyph page tree prunes out all uses of this custom font.
    if (m_fontDataTable.isEmpty())
        return;

    m_fontDataTable.clear();
}

bool CSSSegmentedFontFace::isValid() const
{
    // Valid if at least one font face is valid.
    for (FontFaceList::const_iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it) {
        if ((*it)->cssFontFace()->isValid())
            return true;
    }
    return false;
}

void CSSSegmentedFontFace::fontLoaded(CSSFontFace*)
{
    m_fontSelector->fontLoaded();

    pruneTable();

    if (RuntimeEnabledFeatures::fontLoadEventsEnabled() && !isLoading()) {
        Vector<RefPtr<LoadFontCallback> > callbacks;
        m_callbacks.swap(callbacks);
        for (size_t index = 0; index < callbacks.size(); ++index) {
            if (isLoaded())
                callbacks[index]->notifyLoaded(this);
            else
                callbacks[index]->notifyError(this);
        }
    }
}

void CSSSegmentedFontFace::addFontFace(PassRefPtr<FontFace> prpFontFace, bool cssConnected)
{
    RefPtr<FontFace> fontFace = prpFontFace;
    pruneTable();
    fontFace->cssFontFace()->setSegmentedFontFace(this);
    if (cssConnected) {
        m_fontFaces.insertBefore(m_firstNonCssConnectedFace, fontFace);
    } else {
        FontFaceList::AddResult result = m_fontFaces.add(fontFace);
        if (m_firstNonCssConnectedFace == m_fontFaces.end())
            m_firstNonCssConnectedFace = result.iterator;
    }
}

void CSSSegmentedFontFace::removeFontFace(PassRefPtr<FontFace> prpFontFace)
{
    RefPtr<FontFace> fontFace = prpFontFace;
    FontFaceList::iterator it = m_fontFaces.find(fontFace);
    if (it == m_fontFaces.end())
        return;

    if (it == m_firstNonCssConnectedFace)
        ++m_firstNonCssConnectedFace;
    m_fontFaces.remove(it);

    pruneTable();
    fontFace->cssFontFace()->clearSegmentedFontFace();
}

static void appendFontData(SegmentedFontData* newFontData, PassRefPtr<SimpleFontData> prpFaceFontData, const CSSFontFace::UnicodeRangeSet& ranges)
{
    RefPtr<SimpleFontData> faceFontData = prpFaceFontData;
    unsigned numRanges = ranges.size();
    if (!numRanges) {
        newFontData->appendRange(FontDataRange(0, 0x7FFFFFFF, faceFontData));
        return;
    }

    for (unsigned j = 0; j < numRanges; ++j)
        newFontData->appendRange(FontDataRange(ranges.rangeAt(j).from(), ranges.rangeAt(j).to(), faceFontData));
}

PassRefPtr<FontData> CSSSegmentedFontFace::getFontData(const FontDescription& fontDescription)
{
    if (!isValid())
        return 0;

    FontTraitsMask desiredTraitsMask = fontDescription.traitsMask();
    AtomicString emptyFontFamily = "";
    FontCacheKey key = fontDescription.cacheKey(emptyFontFamily, desiredTraitsMask);

    RefPtr<SegmentedFontData>& fontData = m_fontDataTable.add(key.hash(), 0).iterator->value;
    if (fontData && fontData->numRanges())
        return fontData; // No release, we have a reference to an object in the cache which should retain the ref count it has.

    if (!fontData)
        fontData = SegmentedFontData::create();

    FontDescription requestedFontDescription(fontDescription);
    requestedFontDescription.setTraitsMask(m_traitsMask);
    requestedFontDescription.setSyntheticBold(!(m_traitsMask & (FontWeight600Mask | FontWeight700Mask | FontWeight800Mask | FontWeight900Mask)) && (desiredTraitsMask & (FontWeight600Mask | FontWeight700Mask | FontWeight800Mask | FontWeight900Mask)));
    requestedFontDescription.setSyntheticItalic(!(m_traitsMask & FontStyleItalicMask) && (desiredTraitsMask & FontStyleItalicMask));

    for (FontFaceList::reverse_iterator it = m_fontFaces.rbegin(); it != m_fontFaces.rend(); ++it) {
        if (!(*it)->cssFontFace()->isValid())
            continue;
        if (RefPtr<SimpleFontData> faceFontData = (*it)->cssFontFace()->getFontData(requestedFontDescription)) {
            ASSERT(!faceFontData->isSegmented());
#if ENABLE(SVG_FONTS)
            // For SVG Fonts that specify that they only support the "normal" variant, we will assume they are incapable
            // of small-caps synthesis and just ignore the font face.
            if (faceFontData->isSVGFont() && (desiredTraitsMask & FontVariantSmallCapsMask) && !(m_traitsMask & FontVariantSmallCapsMask))
                continue;
#endif
            appendFontData(fontData.get(), faceFontData.release(), (*it)->cssFontFace()->ranges());
        }
    }
    if (fontData->numRanges())
        return fontData; // No release, we have a reference to an object in the cache which should retain the ref count it has.

    return 0;
}

bool CSSSegmentedFontFace::isLoading() const
{
    for (FontFaceList::const_iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it) {
        if ((*it)->loadStatus() == FontFace::Loading)
            return true;
    }
    return false;
}

bool CSSSegmentedFontFace::isLoaded() const
{
    for (FontFaceList::const_iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it) {
        if ((*it)->loadStatus() != FontFace::Loaded)
            return false;
    }
    return true;
}

void CSSSegmentedFontFace::willUseFontData(const FontDescription& fontDescription)
{
    for (FontFaceList::iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it)
        (*it)->cssFontFace()->willUseFontData(fontDescription);
}

bool CSSSegmentedFontFace::checkFont(const String& text) const
{
    for (FontFaceList::const_iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it) {
        if ((*it)->loadStatus() != FontFace::Loaded && (*it)->cssFontFace()->ranges().intersectsWith(text))
            return false;
    }
    return true;
}

void CSSSegmentedFontFace::loadFont(const FontDescription& fontDescription, const String& text, PassRefPtr<LoadFontCallback> callback)
{
    for (FontFaceList::iterator it = m_fontFaces.begin(); it != m_fontFaces.end(); ++it) {
        if ((*it)->loadStatus() == FontFace::Unloaded && (*it)->cssFontFace()->ranges().intersectsWith(text))
            (*it)->cssFontFace()->load(fontDescription);
    }

    if (callback) {
        if (isLoading())
            m_callbacks.append(callback);
        else if (isLoaded())
            callback->notifyLoaded(this);
        else
            callback->notifyError(this);
    }
}

}