WebCore/FontCache.h

   1 /*
   2  * Copyright (C) 2006, 2008 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 #ifndef FontCache_h
  30 #define FontCache_h
  31
  32 #include <limits.h>
  33 #include <wtf/Vector.h>
  34 #include <wtf/unicode/Unicode.h>
  35
  36 #if PLATFORM(WIN)
  37 #include <objidl.h>
  38 #include <mlang.h>
  39 #endif
  40
  41 namespace WebCore
  42 {
  43
  44 class AtomicString;
  45 class Font;
  46 class FontPlatformData;
  47 class FontData;
  48 class FontDescription;
  49 class FontSelector;
  50 class SimpleFontData;
  51
  52 class FontCache {
  53 public:
  54     friend FontCache* fontCache();
  55
  56     const FontData* getFontData(const Font&, int& familyIndex, FontSelector*);
  57     void releaseFontData(const SimpleFontData*);
  58
  59     // This method is implemented by the platform.
  60     // FIXME: Font data returned by this method never go inactive because callers don't track and release them.
  61     const SimpleFontData* getFontDataForCharacters(const Font&, const UChar* characters, int length);
  62
  63     // Also implemented by the platform.
  64     void platformInit();
  65
  66 #if PLATFORM(WIN)
  67     IMLangFontLink2* getFontLinkInterface();
  68 #endif
  69
  70     void getTraitsInFamily(const AtomicString&, Vector<unsigned>&);
  71
  72     FontPlatformData* getCachedFontPlatformData(const FontDescription&, const AtomicString& family, bool checkingAlternateName = false);
  73     SimpleFontData* getCachedFontData(const FontPlatformData*);
  74     FontPlatformData* getLastResortFallbackFont(const FontDescription&);
  75
  76     void addClient(FontSelector*);
  77     void removeClient(FontSelector*);
  78
  79     unsigned generation();
  80     void invalidate();
  81
  82     size_t fontDataCount();
  83     size_t inactiveFontDataCount();
  84     void purgeInactiveFontData(int count = INT_MAX);
  85
  86 private:
  87     FontCache();
  88
  89     // These methods are implemented by each platform.
  90     FontPlatformData* getSimilarFontPlatformData(const Font&);
  91     FontPlatformData* getCustomFallbackFont(const UInt32 c, const Font&);
  92     bool requiresCustomFallbackFont(const UInt32 c);
  93     FontPlatformData* createFontPlatformData(const FontDescription&, const AtomicString& family);
  94
  95     friend class SimpleFontData;
  96     friend class FontFallbackList;
  97 };
  98
  99 // Get the global fontCache.
 100 FontCache* fontCache();
 101 }
 102
 103 #endif