third_party/WebKit/Source/core/css/CSSSegmentedFontFace.cpp

/*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
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 * 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
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 *    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,
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#include "core/css/CSSSegmentedFontFace.h"

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

namespace blink {

CSSSegmentedFontFace::CSSSegmentedFontFace(CSSFontSelector* fontSelector,
                                           FontTraits traits)
    : m_fontSelector(fontSelector),
      m_traits(traits),
      m_firstNonCssConnectedFace(m_fontFaces.end()),
      m_approximateCharacterCount(0) {}

CSSSegmentedFontFace::~CSSSegmentedFontFace() {}

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 (const auto& fontFace : m_fontFaces) {
    if (fontFace->cssFontFace()->isValid())
      return true;
  }
  return false;
}

void CSSSegmentedFontFace::fontFaceInvalidated() {
  pruneTable();
}

void CSSSegmentedFontFace::addFontFace(FontFace* fontFace, bool cssConnected) {
  pruneTable();
  fontFace->cssFontFace()->setSegmentedFontFace(this);
  if (cssConnected) {
    m_fontFaces.insertBefore(m_firstNonCssConnectedFace, fontFace);
  } else {
    // This is the only place in Blink that is using addReturnIterator.
    FontFaceList::iterator iterator = m_fontFaces.addReturnIterator(fontFace);
    if (m_firstNonCssConnectedFace == m_fontFaces.end())
      m_firstNonCssConnectedFace = iterator;
  }
}

void CSSSegmentedFontFace::removeFontFace(FontFace* fontFace) {
  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();
}

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

  FontTraits desiredTraits = fontDescription.traits();
  FontCacheKey key =
      fontDescription.cacheKey(FontFaceCreationParams(), desiredTraits);

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

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

  FontDescription requestedFontDescription(fontDescription);
  requestedFontDescription.setTraits(m_traits);
  requestedFontDescription.setSyntheticBold(m_traits.weight() < FontWeight600 &&
                                            desiredTraits.weight() >=
                                                FontWeight600);
  requestedFontDescription.setSyntheticItalic(
      m_traits.style() == FontStyleNormal &&
      desiredTraits.style() == FontStyleItalic);

  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 (faceFontData->isCustomFont())
        fontData->appendFace(adoptRef(new FontDataForRangeSet(
            faceFontData.release(), (*it)->cssFontFace()->ranges())));
      else
        fontData->appendFace(adoptRef(new FontDataForRangeSetFromCache(
            faceFontData.release(), (*it)->cssFontFace()->ranges())));
    }
  }
  if (fontData->numFaces()) {
    // No release, we have a reference to an object in the cache which should
    // retain the ref count it has.
    return fontData;
  }

  return nullptr;
}

void CSSSegmentedFontFace::willUseFontData(
    const FontDescription& fontDescription,
    const String& text) {
  m_approximateCharacterCount += text.length();
  for (FontFaceList::reverse_iterator it = m_fontFaces.rbegin();
       it != m_fontFaces.rend(); ++it) {
    if ((*it)->loadStatus() != FontFace::Unloaded)
      break;
    if ((*it)->cssFontFace()->maybeLoadFont(fontDescription, text))
      break;
  }
}

void CSSSegmentedFontFace::willUseRange(
    const blink::FontDescription& fontDescription,
    const blink::FontDataForRangeSet& rangeSet) {
  // Iterating backwards since later defined unicode-range faces override
  // previously defined ones, according to the CSS3 fonts module.
  // https://drafts.csswg.org/css-fonts/#composite-fonts
  for (FontFaceList::reverse_iterator it = m_fontFaces.rbegin();
       it != m_fontFaces.rend(); ++it) {
    CSSFontFace* cssFontFace = (*it)->cssFontFace();
    if (cssFontFace->maybeLoadFont(fontDescription, rangeSet))
      break;
  }
}

bool CSSSegmentedFontFace::checkFont(const String& text) const {
  for (const auto& fontFace : m_fontFaces) {
    if (fontFace->loadStatus() != FontFace::Loaded &&
        fontFace->cssFontFace()->ranges()->intersectsWith(text))
      return false;
  }
  return true;
}

void CSSSegmentedFontFace::match(const String& text,
                                 HeapVector<Member<FontFace>>& faces) const {
  for (const auto& fontFace : m_fontFaces) {
    if (fontFace->cssFontFace()->ranges()->intersectsWith(text))
      faces.append(fontFace);
  }
}

DEFINE_TRACE(CSSSegmentedFontFace) {
  visitor->trace(m_fontSelector);
  visitor->trace(m_fontFaces);
}

}  // namespace blink