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_util.h"
   9 #include "ui/gfx/font_list_impl.h"
  10
  11 namespace {
  12
  13 // Font description of the default font set.
  14 base::LazyInstance<std::string>::Leaky g_default_font_description =
  15     LAZY_INSTANCE_INITIALIZER;
  16
  17 // The default instance of gfx::FontListImpl.
  18 base::LazyInstance<scoped_refptr<gfx::FontListImpl> >::Leaky g_default_impl =
  19     LAZY_INSTANCE_INITIALIZER;
  20 bool g_default_impl_initialized = false;
  21
  22 }  // namespace
  23
  24 namespace gfx {
  25
  26 FontList::FontList() : impl_(GetDefaultImpl()) {}
  27
  28 FontList::FontList(const FontList& other) : impl_(other.impl_) {}
  29
  30 FontList::FontList(const std::string& font_description_string)
  31     : impl_(new FontListImpl(font_description_string)) {}
  32
  33 FontList::FontList(const std::vector<std::string>& font_names,
  34                    int font_style,
  35                    int font_size)
  36     : impl_(new FontListImpl(font_names, font_style, font_size)) {}
  37
  38 FontList::FontList(const std::vector<Font>& fonts)
  39     : impl_(new FontListImpl(fonts)) {}
  40
  41 FontList::FontList(const Font& font) : impl_(new FontListImpl(font)) {}
  42
  43 FontList::~FontList() {}
  44
  45 FontList& FontList::operator=(const FontList& other) {
  46   impl_ = other.impl_;
  47   return *this;
  48 }
  49
  50 // static
  51 void FontList::SetDefaultFontDescription(const std::string& font_description) {
  52   // The description string must end with "px" for size in pixel, or must be
  53   // the empty string, which specifies to use a single default font.
  54   DCHECK(font_description.empty() ||
  55          EndsWith(font_description, "px", true));
  56
  57   g_default_font_description.Get() = font_description;
  58   g_default_impl_initialized = false;
  59 }
  60
  61 FontList FontList::Derive(int size_delta, int font_style) const {
  62   return FontList(impl_->Derive(size_delta, font_style));
  63 }
  64
  65 FontList FontList::DeriveWithSizeDelta(int size_delta) const {
  66   return Derive(size_delta, GetFontStyle());
  67 }
  68
  69 FontList FontList::DeriveWithStyle(int font_style) const {
  70   return Derive(0, font_style);
  71 }
  72
  73 gfx::FontList FontList::DeriveWithHeightUpperBound(int height) const {
  74   gfx::FontList font_list(*this);
  75   for (int font_size = font_list.GetFontSize(); font_size > 1; --font_size) {
  76     const int internal_leading =
  77         font_list.GetBaseline() - font_list.GetCapHeight();
  78     // Some platforms don't support getting the cap height, and simply return
  79     // the entire font ascent from GetCapHeight().  Centering the ascent makes
  80     // the font look too low, so if GetCapHeight() returns the ascent, center
  81     // the entire font height instead.
  82     const int space =
  83         height - ((internal_leading != 0) ?
  84                   font_list.GetCapHeight() : font_list.GetHeight());
  85     const int y_offset = space / 2 - internal_leading;
  86     const int space_at_bottom = height - (y_offset + font_list.GetHeight());
  87     if ((y_offset >= 0) && (space_at_bottom >= 0))
  88       break;
  89     font_list = font_list.DeriveWithSizeDelta(-1);
  90   }
  91   return font_list;
  92 }
  93
  94 int FontList::GetHeight() const {
  95   return impl_->GetHeight();
  96 }
  97
  98 int FontList::GetBaseline() const {
  99   return impl_->GetBaseline();
 100 }
 101
 102 int FontList::GetCapHeight() const {
 103   return impl_->GetCapHeight();
 104 }
 105
 106 int FontList::GetExpectedTextWidth(int length) const {
 107   return impl_->GetExpectedTextWidth(length);
 108 }
 109
 110 int FontList::GetFontStyle() const {
 111   return impl_->GetFontStyle();
 112 }
 113
 114 const std::string& FontList::GetFontDescriptionString() const {
 115   return impl_->GetFontDescriptionString();
 116 }
 117
 118 int FontList::GetFontSize() const {
 119   return impl_->GetFontSize();
 120 }
 121
 122 const std::vector<Font>& FontList::GetFonts() const {
 123   return impl_->GetFonts();
 124 }
 125
 126 const Font& FontList::GetPrimaryFont() const {
 127   return impl_->GetPrimaryFont();
 128 }
 129
 130 FontList::FontList(FontListImpl* impl) : impl_(impl) {}
 131
 132 // static
 133 const scoped_refptr<FontListImpl>& FontList::GetDefaultImpl() {
 134   // SetDefaultFontDescription() must be called and the default font description
 135   // must be set earlier than any call of this function.
 136   DCHECK(!(g_default_font_description == NULL))  // != is not overloaded.
 137       << "SetDefaultFontDescription has not been called.";
 138
 139   if (!g_default_impl_initialized) {
 140     g_default_impl.Get() =
 141         g_default_font_description.Get().empty() ?
 142             new FontListImpl(Font()) :
 143             new FontListImpl(g_default_font_description.Get());
 144     g_default_impl_initialized = true;
 145   }
 146
 147   return g_default_impl.Get();
 148 }
 149
 150 }  // namespace gfx