ui/gfx/font_list.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_list.h"
   6
   7 #include "base/lazy_instance.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/string_split.h"
  10 #include "base/strings/string_util.h"
  11 #include "ui/gfx/font_list_impl.h"
  12
  13 namespace {
  14
  15 // Font description of the default font set.
  16 base::LazyInstance<std::string>::Leaky g_default_font_description =
  17     LAZY_INSTANCE_INITIALIZER;
  18
  19 // The default instance of gfx::FontListImpl.
  20 base::LazyInstance<scoped_refptr<gfx::FontListImpl> >::Leaky g_default_impl =
  21     LAZY_INSTANCE_INITIALIZER;
  22 bool g_default_impl_initialized = false;
  23
  24 }  // namespace
  25
  26 namespace gfx {
  27
  28 // static
  29 bool FontList::ParseDescription(const std::string& description,
  30                                 std::vector<std::string>* families_out,
  31                                 int* style_out,
  32                                 int* size_pixels_out) {
  33   DCHECK(families_out);
  34   DCHECK(style_out);
  35   DCHECK(size_pixels_out);
  36
  37   base::SplitString(description, ',', families_out);
  38   if (families_out->empty())
  39     return false;
  40   for (auto& family : *families_out)
  41     base::TrimWhitespaceASCII(family, base::TRIM_ALL, &family);
  42
  43   // The last item is "[STYLE1] [STYLE2] [...] SIZE".
  44   std::vector<std::string> styles;
  45   base::SplitStringAlongWhitespace(families_out->back(), &styles);
  46   families_out->pop_back();
  47   if (styles.empty())
  48     return false;
  49
  50   // The size takes the form "<INT>px".
  51   std::string size_string = styles.back();
  52   styles.pop_back();
  53   if (!EndsWith(size_string, "px", true /* case_sensitive */))
  54     return false;
  55   size_string.resize(size_string.size() - 2);
  56   if (!base::StringToInt(size_string, size_pixels_out) ||
  57       *size_pixels_out <= 0)
  58     return false;
  59
  60   // Font supports BOLD and ITALIC; underline is supported via RenderText.
  61   *style_out = gfx::Font::NORMAL;
  62   for (const auto& style_string : styles) {
  63     if (style_string == "Bold")
  64       *style_out |= gfx::Font::BOLD;
  65     else if (style_string == "Italic")
  66       *style_out |= gfx::Font::ITALIC;
  67     else
  68       return false;
  69   }
  70
  71   return true;
  72 }
  73
  74 FontList::FontList() : impl_(GetDefaultImpl()) {}
  75
  76 FontList::FontList(const FontList& other) : impl_(other.impl_) {}
  77
  78 FontList::FontList(const std::string& font_description_string)
  79     : impl_(new FontListImpl(font_description_string)) {}
  80
  81 FontList::FontList(const std::vector<std::string>& font_names,
  82                    int font_style,
  83                    int font_size)
  84     : impl_(new FontListImpl(font_names, font_style, font_size)) {}
  85
  86 FontList::FontList(const std::vector<Font>& fonts)
  87     : impl_(new FontListImpl(fonts)) {}
  88
  89 FontList::FontList(const Font& font) : impl_(new FontListImpl(font)) {}
  90
  91 FontList::~FontList() {}
  92
  93 FontList& FontList::operator=(const FontList& other) {
  94   impl_ = other.impl_;
  95   return *this;
  96 }
  97
  98 // static
  99 void FontList::SetDefaultFontDescription(const std::string& font_description) {
 100   // The description string must end with "px" for size in pixel, or must be
 101   // the empty string, which specifies to use a single default font.
 102   DCHECK(font_description.empty() ||
 103          EndsWith(font_description, "px", true));
 104
 105   g_default_font_description.Get() = font_description;
 106   g_default_impl_initialized = false;
 107 }
 108
 109 FontList FontList::Derive(int size_delta, int font_style) const {
 110   return FontList(impl_->Derive(size_delta, font_style));
 111 }
 112
 113 FontList FontList::DeriveWithSizeDelta(int size_delta) const {
 114   return Derive(size_delta, GetFontStyle());
 115 }
 116
 117 FontList FontList::DeriveWithStyle(int font_style) const {
 118   return Derive(0, font_style);
 119 }
 120
 121 gfx::FontList FontList::DeriveWithHeightUpperBound(int height) const {
 122   gfx::FontList font_list(*this);
 123   for (int font_size = font_list.GetFontSize(); font_size > 1; --font_size) {
 124     const int internal_leading =
 125         font_list.GetBaseline() - font_list.GetCapHeight();
 126     // Some platforms don't support getting the cap height, and simply return
 127     // the entire font ascent from GetCapHeight().  Centering the ascent makes
 128     // the font look too low, so if GetCapHeight() returns the ascent, center
 129     // the entire font height instead.
 130     const int space =
 131         height - ((internal_leading != 0) ?
 132                   font_list.GetCapHeight() : font_list.GetHeight());
 133     const int y_offset = space / 2 - internal_leading;
 134     const int space_at_bottom = height - (y_offset + font_list.GetHeight());
 135     if ((y_offset >= 0) && (space_at_bottom >= 0))
 136       break;
 137     font_list = font_list.DeriveWithSizeDelta(-1);
 138   }
 139   return font_list;
 140 }
 141
 142 int FontList::GetHeight() const {
 143   return impl_->GetHeight();
 144 }
 145
 146 int FontList::GetBaseline() const {
 147   return impl_->GetBaseline();
 148 }
 149
 150 int FontList::GetCapHeight() const {
 151   return impl_->GetCapHeight();
 152 }
 153
 154 int FontList::GetExpectedTextWidth(int length) const {
 155   return impl_->GetExpectedTextWidth(length);
 156 }
 157
 158 int FontList::GetFontStyle() const {
 159   return impl_->GetFontStyle();
 160 }
 161
 162 int FontList::GetFontSize() const {
 163   return impl_->GetFontSize();
 164 }
 165
 166 const std::vector<Font>& FontList::GetFonts() const {
 167   return impl_->GetFonts();
 168 }
 169
 170 const Font& FontList::GetPrimaryFont() const {
 171   return impl_->GetPrimaryFont();
 172 }
 173
 174 FontList::FontList(FontListImpl* impl) : impl_(impl) {}
 175
 176 // static
 177 const scoped_refptr<FontListImpl>& FontList::GetDefaultImpl() {
 178   // SetDefaultFontDescription() must be called and the default font description
 179   // must be set earlier than any call of this function.
 180   DCHECK(!(g_default_font_description == NULL))  // != is not overloaded.
 181       << "SetDefaultFontDescription has not been called.";
 182
 183   if (!g_default_impl_initialized) {
 184     g_default_impl.Get() =
 185         g_default_font_description.Get().empty() ?
 186             new FontListImpl(Font()) :
 187             new FontListImpl(g_default_font_description.Get());
 188     g_default_impl_initialized = true;
 189   }
 190
 191   return g_default_impl.Get();
 192 }
 193
 194 }  // namespace gfx