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      1 /*
      2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     14  *     its contributors may be used to endorse or promote products derived
     15  *     from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "config.h"
     30 #include "core/platform/graphics/FontFallbackList.h"
     31 
     32 #include "core/platform/graphics/FontCache.h"
     33 #include "core/platform/graphics/SegmentedFontData.h"
     34 
     35 namespace WebCore {
     36 
     37 FontFallbackList::FontFallbackList()
     38     : m_pageZero(0)
     39     , m_cachedPrimarySimpleFontData(0)
     40     , m_fontSelector(0)
     41     , m_fontSelectorVersion(0)
     42     , m_familyIndex(0)
     43     , m_generation(fontCache()->generation())
     44     , m_pitch(UnknownPitch)
     45     , m_loadingCustomFonts(false)
     46 {
     47 }
     48 
     49 void FontFallbackList::invalidate(PassRefPtr<FontSelector> fontSelector)
     50 {
     51     releaseFontData();
     52     m_fontList.clear();
     53     m_pageZero = 0;
     54     m_pages.clear();
     55     m_cachedPrimarySimpleFontData = 0;
     56     m_familyIndex = 0;
     57     m_pitch = UnknownPitch;
     58     m_loadingCustomFonts = false;
     59     m_fontSelector = fontSelector;
     60     m_fontSelectorVersion = m_fontSelector ? m_fontSelector->version() : 0;
     61     m_generation = fontCache()->generation();
     62     m_widthCache.clear();
     63 }
     64 
     65 void FontFallbackList::releaseFontData()
     66 {
     67     unsigned numFonts = m_fontList.size();
     68     for (unsigned i = 0; i < numFonts; ++i) {
     69         if (!m_fontList[i]->isCustomFont()) {
     70             ASSERT(!m_fontList[i]->isSegmented());
     71             fontCache()->releaseFontData(static_cast<const SimpleFontData*>(m_fontList[i].get()));
     72         }
     73     }
     74 }
     75 
     76 void FontFallbackList::determinePitch(const Font* font) const
     77 {
     78     const FontData* fontData = primaryFontData(font);
     79     if (!fontData->isSegmented())
     80         m_pitch = static_cast<const SimpleFontData*>(fontData)->pitch();
     81     else {
     82         const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
     83         unsigned numRanges = segmentedFontData->numRanges();
     84         if (numRanges == 1)
     85             m_pitch = segmentedFontData->rangeAt(0).fontData()->pitch();
     86         else
     87             m_pitch = VariablePitch;
     88     }
     89 }
     90 
     91 const FontData* FontFallbackList::primaryFontData(const Font* f) const
     92 {
     93     for (unsigned fontIndex = 0; ; ++fontIndex) {
     94         const FontData* fontData = fontDataAt(f, fontIndex);
     95         if (!fontData) {
     96             // All fonts are custom fonts and a loading. Return the first FontData.
     97             // FIXME: Correct fallback to the default font.
     98             return fontDataAt(f, 0);
     99         }
    100 
    101         // When a custom font is loading, we should use the correct fallback font to layout the text.
    102         // Here skip the temporary font for the loading custom font which may not act as the correct fallback font.
    103         if (!fontData->isLoading())
    104             return fontData;
    105     }
    106 }
    107 
    108 const FontData* FontFallbackList::fontDataAt(const Font* font, unsigned realizedFontIndex) const
    109 {
    110     if (realizedFontIndex < m_fontList.size())
    111         return m_fontList[realizedFontIndex].get(); // This fallback font is already in our list.
    112 
    113     // Make sure we're not passing in some crazy value here.
    114     ASSERT(realizedFontIndex == m_fontList.size());
    115 
    116     if (m_familyIndex == cAllFamiliesScanned)
    117         return 0;
    118 
    119     // Ask the font cache for the font data.
    120     // We are obtaining this font for the first time.  We keep track of the families we've looked at before
    121     // in |m_familyIndex|, so that we never scan the same spot in the list twice.  getFontData will adjust our
    122     // |m_familyIndex| as it scans for the right font to make.
    123     ASSERT(fontCache()->generation() == m_generation);
    124     RefPtr<FontData> result = fontCache()->getFontData(*font, m_familyIndex, m_fontSelector.get());
    125     if (result) {
    126         m_fontList.append(result);
    127         if (result->isLoading())
    128             m_loadingCustomFonts = true;
    129     }
    130     return result.get();
    131 }
    132 
    133 void FontFallbackList::setPlatformFont(const FontPlatformData& platformData)
    134 {
    135     m_familyIndex = cAllFamiliesScanned;
    136     ASSERT(fontCache()->generation() == m_generation);
    137     RefPtr<FontData> fontData = fontCache()->getFontResourceData(&platformData);
    138     m_fontList.append(fontData);
    139 }
    140 
    141 }
    142