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      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
    151