ui/gfx/font_render_params_linux.cc

   1 // Copyright (c) 2012 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_render_params_linux.h"
   6
   7 #include "base/logging.h"
   8
   9 #if defined(TOOLKIT_GTK)
  10 #include <gtk/gtk.h>
  11 #else
  12 #include <fontconfig/fontconfig.h>
  13 #include "base/command_line.h"
  14 #include "ui/gfx/switches.h"
  15 #endif
  16
  17 namespace gfx {
  18
  19 namespace {
  20
  21 // Initializes |params| with the system's default settings. |renderer| is true
  22 // when setting WebKit renderer defaults.
  23 void LoadDefaults(FontRenderParams* params, bool renderer) {
  24 #if defined(TOOLKIT_GTK)
  25   params->antialiasing = true;
  26   params->subpixel_positioning = false;
  27   // TODO(wangxianzhu): autohinter is now true to keep original behavior
  28   // of WebKit, but it might not be the best value.
  29   params->autohinter = true;
  30   params->use_bitmaps = true;
  31   params->hinting = FontRenderParams::HINTING_SLIGHT;
  32   params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_NONE;
  33
  34   GtkSettings* gtk_settings = gtk_settings_get_default();
  35   CHECK(gtk_settings);
  36   gint gtk_antialias = 0;
  37   gint gtk_hinting = 0;
  38   gchar* gtk_hint_style = NULL;
  39   gchar* gtk_rgba = NULL;
  40   g_object_get(gtk_settings,
  41                "gtk-xft-antialias", &gtk_antialias,
  42                "gtk-xft-hinting", &gtk_hinting,
  43                "gtk-xft-hintstyle", &gtk_hint_style,
  44                "gtk-xft-rgba", &gtk_rgba,
  45                NULL);
  46
  47   // g_object_get() doesn't tell us whether the properties were present or not,
  48   // but if they aren't (because gnome-settings-daemon isn't running), we'll get
  49   // NULL values for the strings.
  50   if (gtk_hint_style && gtk_rgba) {
  51     params->antialiasing = gtk_antialias;
  52
  53     if (gtk_hinting == 0 || strcmp(gtk_hint_style, "hintnone") == 0)
  54       params->hinting = FontRenderParams::HINTING_NONE;
  55     else if (strcmp(gtk_hint_style, "hintslight") == 0)
  56       params->hinting = FontRenderParams::HINTING_SLIGHT;
  57     else if (strcmp(gtk_hint_style, "hintmedium") == 0)
  58       params->hinting = FontRenderParams::HINTING_MEDIUM;
  59     else if (strcmp(gtk_hint_style, "hintfull") == 0)
  60       params->hinting = FontRenderParams::HINTING_FULL;
  61
  62     if (strcmp(gtk_rgba, "none") == 0)
  63       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_NONE;
  64     else if (strcmp(gtk_rgba, "rgb") == 0)
  65       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_RGB;
  66     else if (strcmp(gtk_rgba, "bgr") == 0)
  67       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_BGR;
  68     else if (strcmp(gtk_rgba, "vrgb") == 0)
  69       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_VRGB;
  70     else if (strcmp(gtk_rgba, "vbgr") == 0)
  71       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_VBGR;
  72   }
  73
  74   g_free(gtk_hint_style);
  75   g_free(gtk_rgba);
  76 #else
  77   // For non-GTK builds (read: Aura), just use reasonable hardcoded values.
  78   params->antialiasing = true;
  79   params->autohinter = true;
  80   params->use_bitmaps = true;
  81
  82   // Fetch default subpixel rendering settings from FontConfig.
  83   FcPattern* pattern = FcPatternCreate();
  84   FcResult result;
  85   FcPattern* match = FcFontMatch(0, pattern, &result);
  86   DCHECK(match);
  87   int fc_rgba = FC_RGBA_RGB;
  88   FcPatternGetInteger(match, FC_RGBA, 0, &fc_rgba);
  89   FcPatternDestroy(pattern);
  90   FcPatternDestroy(match);
  91
  92   switch (fc_rgba) {
  93     case FC_RGBA_RGB:
  94       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_RGB;
  95       break;
  96     case FC_RGBA_BGR:
  97       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_BGR;
  98       break;
  99     case FC_RGBA_VRGB:
 100       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_VRGB;
 101       break;
 102     case FC_RGBA_VBGR:
 103       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_VBGR;
 104       break;
 105     default:
 106       params->subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_NONE;
 107   }
 108
 109   params->subpixel_positioning =
 110       CommandLine::ForCurrentProcess()->HasSwitch(
 111           renderer ?
 112           switches::kEnableWebkitTextSubpixelPositioning :
 113           switches::kEnableBrowserTextSubpixelPositioning);
 114
 115   // To enable subpixel positioning, we need to disable hinting.
 116   if (params->subpixel_positioning)
 117     params->hinting = FontRenderParams::HINTING_NONE;
 118   else
 119     params->hinting = FontRenderParams::HINTING_SLIGHT;
 120 #endif
 121 }
 122
 123 }  // namespace
 124
 125 const FontRenderParams& GetDefaultFontRenderParams() {
 126   static bool loaded_defaults = false;
 127   static FontRenderParams default_params;
 128   if (!loaded_defaults)
 129     LoadDefaults(&default_params, /* renderer */ false);
 130   loaded_defaults = true;
 131   return default_params;
 132 }
 133
 134 const FontRenderParams& GetDefaultWebKitFontRenderParams() {
 135   static bool loaded_defaults = false;
 136   static FontRenderParams default_params;
 137   if (!loaded_defaults)
 138     LoadDefaults(&default_params, /* renderer */ true);
 139   loaded_defaults = true;
 140   return default_params;
 141 }
 142
 143 }  // namespace gfx