Source/core/css/CSSFontFace.cpp

/*
 * Copyright (C) 2007, 2008, 2011 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
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "config.h"
#include "core/css/CSSFontFace.h"

#include "core/css/CSSFontSelector.h"
#include "core/css/CSSSegmentedFontFace.h"
#include "core/css/FontFaceSet.h"
#include "core/dom/Document.h"
#include "core/frame/UseCounter.h"
#include "platform/fonts/SimpleFontData.h"

namespace WebCore {

void CSSFontFace::addSource(PassOwnPtr<CSSFontFaceSource> source)
{
    source->setFontFace(this);
    m_sources.append(source);
}

void CSSFontFace::setSegmentedFontFace(CSSSegmentedFontFace* segmentedFontFace)
{
    ASSERT(!m_segmentedFontFace);
    m_segmentedFontFace = segmentedFontFace;
}

void CSSFontFace::beginLoadIfNeeded(CSSFontFaceSource* source, CSSFontSelector* fontSelector)
{
    if (source->resource() && source->resource()->stillNeedsLoad()) {
        if (!fontSelector) {
            if (!m_segmentedFontFace)
                return;
            fontSelector = m_segmentedFontFace->fontSelector();
        }
        fontSelector->beginLoadingFontSoon(source->resource());
    }

    if (loadStatus() == FontFace::Unloaded)
        setLoadStatus(FontFace::Loading);
}

void CSSFontFace::fontLoaded(CSSFontFaceSource* source)
{
    if (!isValid() || source != m_sources.first())
        return;

    if (loadStatus() == FontFace::Loading) {
        if (source->ensureFontData()) {
            setLoadStatus(FontFace::Loaded);
            Document* document = m_segmentedFontFace ? m_segmentedFontFace->fontSelector()->document() : 0;
            if (document && source->isSVGFontFaceSource())
                UseCounter::count(*document, UseCounter::SVGFontInCSS);
        } else {
            m_sources.removeFirst();
            if (!isValid())
                setLoadStatus(FontFace::Error);
        }
    }

    if (m_segmentedFontFace)
        m_segmentedFontFace->fontLoaded(this);
}

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

    while (!m_sources.isEmpty()) {
        OwnPtr<CSSFontFaceSource>& source = m_sources.first();
        if (RefPtr<SimpleFontData> result = source->getFontData(fontDescription)) {
            if (loadStatus() == FontFace::Unloaded && (source->isLoading() || source->isLoaded()))
                setLoadStatus(FontFace::Loading);
            if (loadStatus() == FontFace::Loading && source->isLoaded())
                setLoadStatus(FontFace::Loaded);
            return result.release();
        }
        m_sources.removeFirst();
    }

    if (loadStatus() == FontFace::Unloaded)
        setLoadStatus(FontFace::Loading);
    if (loadStatus() == FontFace::Loading)
        setLoadStatus(FontFace::Error);
    return 0;
}

void CSSFontFace::willUseFontData(const FontDescription& fontDescription)
{
    // Kicks off font load here only if the @font-face has no unicode-range.
    // @font-faces with unicode-range will be loaded when a GlyphPage for the
    // font is created.
    // FIXME: Pass around the text to render from RenderText, and kick download
    // if m_ranges intersects with the text. Make sure this does not cause
    // performance regression.
    if (m_ranges.isEntireRange())
        load(fontDescription);
}

void CSSFontFace::load(const FontDescription& fontDescription, CSSFontSelector* fontSelector)
{
    if (loadStatus() != FontFace::Unloaded)
        return;
    setLoadStatus(FontFace::Loading);

    while (!m_sources.isEmpty()) {
        OwnPtr<CSSFontFaceSource>& source = m_sources.first();
        if (source->isValid()) {
            if (source->isLocal()) {
                if (source->isLocalFontAvailable(fontDescription)) {
                    setLoadStatus(FontFace::Loaded);
                    return;
                }
            } else {
                if (!source->isLoaded()) {
                    beginLoadIfNeeded(source.get(), fontSelector);
                } else {
                    setLoadStatus(FontFace::Loaded);
                }
                return;
            }
        }
        m_sources.removeFirst();
    }
    setLoadStatus(FontFace::Error);
}

void CSSFontFace::setLoadStatus(FontFace::LoadStatus newStatus)
{
    ASSERT(m_fontFace);
    m_fontFace->setLoadStatus(newStatus);

    if (!m_segmentedFontFace)
        return;
    Document* document = m_segmentedFontFace->fontSelector()->document();
    if (!document)
        return;

    switch (newStatus) {
    case FontFace::Loading:
        FontFaceSet::from(document)->beginFontLoading(m_fontFace);
        break;
    case FontFace::Loaded:
        FontFaceSet::from(document)->fontLoaded(m_fontFace);
        break;
    case FontFace::Error:
        FontFaceSet::from(document)->loadError(m_fontFace);
        break;
    default:
        break;
    }
}

bool CSSFontFace::UnicodeRangeSet::intersectsWith(const String& text) const
{
    if (text.isEmpty())
        return false;
    if (isEntireRange())
        return true;

    // FIXME: This takes O(text.length() * m_ranges.size()) time. It would be
    // better to make m_ranges sorted and use binary search.
    unsigned index = 0;
    while (index < text.length()) {
        UChar32 c = text.characterStartingAt(index);
        index += U16_LENGTH(c);
        for (unsigned i = 0; i < m_ranges.size(); i++) {
            if (m_ranges[i].contains(c))
                return true;
        }
    }
    return false;
}

}