app/gfx/font_gtk.cc

   1 // Copyright (c) 2006-2008 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 "app/gfx/font.h"
   6
   7 #include <fontconfig/fontconfig.h>
   8 #include <gtk/gtk.h>
   9
  10 #include "base/logging.h"
  11 #include "base/string_piece.h"
  12 #include "base/utf_string_conversions.h"
  13
  14 namespace gfx {
  15
  16 Font* Font::default_font_ = NULL;
  17
  18 // Find the best match font for |family_name| in the same way as Skia
  19 // to make sure CreateFont() successfully creates a default font.  In
  20 // Skia, it only checks the best match font.  If it failed to find
  21 // one, SkTypeface will be NULL for that font family.  It eventually
  22 // causes a segfault.  For example, family_name = "Sans" and system
  23 // may have various fonts.  The first font family in FcPattern will be
  24 // "DejaVu Sans" but a font family returned by FcFontMatch will be "VL
  25 // PGothic".  In this case, SkTypeface for "Sans" returns NULL even if
  26 // the system has a font for "Sans" font family.  See FontMatch() in
  27 // skia/ports/SkFontHost_fontconfig.cpp for more detail.
  28 static std::wstring FindBestMatchFontFamilyName(const char* family_name) {
  29   FcPattern* pattern = FcPatternCreate();
  30   FcValue fcvalue;
  31   fcvalue.type = FcTypeString;
  32   char* family_name_copy = strdup(family_name);
  33   fcvalue.u.s = reinterpret_cast<FcChar8*>(family_name_copy);
  34   FcPatternAdd(pattern, FC_FAMILY, fcvalue, 0);
  35   FcConfigSubstitute(0, pattern, FcMatchPattern);
  36   FcDefaultSubstitute(pattern);
  37   FcResult result;
  38   FcPattern* match = FcFontMatch(0, pattern, &result);
  39   DCHECK(match) << "Could not find font: " << family_name;
  40   FcChar8* match_family;
  41   FcPatternGetString(match, FC_FAMILY, 0, &match_family);
  42
  43   std::wstring font_family = UTF8ToWide(
  44       reinterpret_cast<char*>(match_family));
  45   FcPatternDestroy(match);
  46   FcPatternDestroy(pattern);
  47   free(family_name_copy);
  48   return font_family;
  49 }
  50
  51 // static
  52 Font Font::CreateFont(PangoFontDescription* desc) {
  53   gint size = pango_font_description_get_size(desc);
  54   const char* family_name = pango_font_description_get_family(desc);
  55
  56   // Find best match font for |family_name| to make sure we can get
  57   // a SkTypeface for the default font.
  58   // TODO(agl): remove this.
  59   std::wstring font_family = FindBestMatchFontFamilyName(family_name);
  60
  61   Font font = CreateFont(font_family, size / PANGO_SCALE);
  62   int style = 0;
  63   if (pango_font_description_get_weight(desc) == PANGO_WEIGHT_BOLD) {
  64     // TODO(davemoore) What should we do about other weights? We currently
  65     // only support BOLD.
  66     style |= BOLD;
  67   }
  68   if (pango_font_description_get_style(desc) == PANGO_STYLE_ITALIC) {
  69     // TODO(davemoore) What about PANGO_STYLE_OBLIQUE?
  70     style |= ITALIC;
  71   }
  72   if (style != 0) {
  73     font = font.DeriveFont(0, style);
  74   }
  75   return Font(font);
  76 }
  77
  78 // Get the default gtk system font (name and size).
  79 Font::Font() {
  80   if (default_font_ == NULL) {
  81     GtkSettings* settings = gtk_settings_get_default();
  82
  83     gchar* font_name = NULL;
  84     g_object_get(settings, "gtk-font-name", &font_name, NULL);
  85
  86     // Temporary CHECK for helping track down
  87     // http://code.google.com/p/chromium/issues/detail?id=12530
  88     CHECK(font_name) << " Unable to get gtk-font-name for default font.";
  89
  90     PangoFontDescription* desc =
  91         pango_font_description_from_string(font_name);
  92     default_font_ = new Font(CreateFont(desc));
  93     pango_font_description_free(desc);
  94     g_free(font_name);
  95
  96     DCHECK(default_font_);
  97   }
  98
  99   CopyFont(*default_font_);
 100 }
 101
 102 // static
 103 PangoFontDescription* Font::PangoFontFromGfxFont(
 104     const gfx::Font& gfx_font) {
 105   gfx::Font font = gfx_font;  // Copy so we can call non-const methods.
 106   PangoFontDescription* pfd = pango_font_description_new();
 107   pango_font_description_set_family(pfd, WideToUTF8(font.FontName()).c_str());
 108   pango_font_description_set_size(pfd, font.FontSize() * PANGO_SCALE);
 109
 110   switch (font.style()) {
 111     case gfx::Font::NORMAL:
 112       // Nothing to do, should already be PANGO_STYLE_NORMAL.
 113       break;
 114     case gfx::Font::BOLD:
 115       pango_font_description_set_weight(pfd, PANGO_WEIGHT_BOLD);
 116       break;
 117     case gfx::Font::ITALIC:
 118       pango_font_description_set_style(pfd, PANGO_STYLE_ITALIC);
 119       break;
 120     case gfx::Font::UNDERLINED:
 121       // TODO(deanm): How to do underlined?  Where do we use it?  Probably have
 122       // to paint it ourselves, see pango_font_metrics_get_underline_position.
 123       break;
 124   }
 125
 126   return pfd;
 127 }
 128
 129 }  // namespace gfx