ui/gfx/font_fallback_linux.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/gfx/font_fallback.h"
   6
   7 #include <fontconfig/fontconfig.h>
   8
   9 #include <map>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/lazy_instance.h"
  14
  15 namespace gfx {
  16
  17 namespace {
  18
  19 typedef std::map<std::string, std::vector<std::string> > FallbackCache;
  20 base::LazyInstance<FallbackCache>::Leaky g_fallback_cache =
  21     LAZY_INSTANCE_INITIALIZER;
  22
  23 }  // namespace
  24
  25 std::vector<std::string> GetFallbackFontFamilies(
  26     const std::string& font_family) {
  27   std::vector<std::string>* fallback_fonts =
  28       &g_fallback_cache.Get()[font_family];
  29   if (!fallback_fonts->empty())
  30     return *fallback_fonts;
  31
  32   FcPattern* pattern = FcPatternCreate();
  33   FcValue family;
  34   family.type = FcTypeString;
  35   family.u.s = reinterpret_cast<const FcChar8*>(font_family.c_str());
  36   FcPatternAdd(pattern, FC_FAMILY, family, FcFalse);
  37   if (FcConfigSubstitute(NULL, pattern, FcMatchPattern) == FcTrue) {
  38     FcDefaultSubstitute(pattern);
  39     FcResult result;
  40     FcFontSet* fonts = FcFontSort(NULL, pattern, FcTrue, NULL, &result);
  41     if (fonts) {
  42       for (int i = 0; i < fonts->nfont; ++i) {
  43         char* name = NULL;
  44         FcPatternGetString(fonts->fonts[i], FC_FAMILY, 0,
  45             reinterpret_cast<FcChar8**>(&name));
  46         // FontConfig returns multiple fonts with the same family name and
  47         // different configurations. Check to prevent duplicate family names.
  48         if (fallback_fonts->empty() || fallback_fonts->back() != name)
  49           fallback_fonts->push_back(std::string(name));
  50       }
  51       FcFontSetDestroy(fonts);
  52     }
  53   }
  54   FcPatternDestroy(pattern);
  55
  56   if (fallback_fonts->empty())
  57     fallback_fonts->push_back(font_family);
  58
  59   return *fallback_fonts;
  60 }
  61
  62 }  // namespace gfx