ui/gfx/font_list.h

   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 #ifndef UI_GFX_FONT_LIST_H_
   6 #define UI_GFX_FONT_LIST_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "ui/base/ui_export.h"
  12 #include "ui/gfx/font.h"
  13
  14 namespace gfx {
  15
  16 // FontList represents a list of fonts either in the form of Font vector or in
  17 // the form of a string representing font names, styles, and size.
  18 //
  19 // The string representation is in the form "FAMILY_LIST [STYLE_OPTIONS] SIZE",
  20 // where FAMILY_LIST is a comma separated list of families terminated by a
  21 // comma, STYLE_OPTIONS is a whitespace separated list of words where each word
  22 // describes one of style, variant, weight, stretch, or gravity, and SIZE is
  23 // a decimal number followed by "px" for absolute size. STYLE_OPTIONS may be
  24 // absent.
  25 //
  26 // The string format complies with that of Pango detailed at
  27 // http://developer.gnome.org/pango/stable/pango-Fonts.html#pango-font-description-from-string
  28 //
  29 // FontList could be initialized either way without conversion to the other
  30 // form. The conversion to the other form is done only when asked to get the
  31 // other form.
  32 //
  33 // FontList allows operator= since FontList is a data member type in RenderText,
  34 // and operator= is used in RenderText::SetFontList().
  35 class UI_EXPORT FontList {
  36  public:
  37   // Creates a font list with a Font with default name and style.
  38   FontList();
  39
  40   // Creates a font list from a string representing font names, styles, and
  41   // size.
  42   explicit FontList(const std::string& font_description_string);
  43
  44   // Creates a font list from a Font vector.
  45   // All fonts in this vector should have the same style and size.
  46   explicit FontList(const std::vector<Font>& fonts);
  47
  48   // Creates a font list from a Font.
  49   explicit FontList(const Font& font);
  50
  51   ~FontList();
  52
  53   // Returns a new FontList with the given |font_style| flags.
  54   FontList DeriveFontList(int font_style) const;
  55
  56   // Returns a new FontList with the same font names and style but with the
  57   // given font |size| in pixels.
  58   FontList DeriveFontListWithSize(int size) const;
  59
  60   // Returns the |gfx::Font::FontStyle| style flags for this font list.
  61   int GetFontStyle() const;
  62
  63   // Returns a string representing font names, styles, and size. If the FontList
  64   // is initialized by a vector of Font, use the first font's style and size
  65   // for the description.
  66   const std::string& GetFontDescriptionString() const;
  67
  68   // Returns the Font vector.
  69   const std::vector<Font>& GetFonts() const;
  70
  71  private:
  72   // A vector of Font. If FontList is constructed with font description string,
  73   // |fonts_| is not initialized during construction. Instead, it is computed
  74   // lazily when user asked to get the font vector.
  75   mutable std::vector<Font> fonts_;
  76
  77   // A string representing font names, styles, and sizes.
  78   // Please refer to the comments before class declaration for details on string
  79   // format.
  80   // If FontList is constructed with a vector of font,
  81   // |font_description_string_| is not initialized during construction. Instead,
  82   // it is computed lazily when user asked to get the font description string.
  83   mutable std::string font_description_string_;
  84 };
  85
  86 }  // namespace gfx
  87
  88 #endif  // UI_GFX_FONT_LIST_H_