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/gfx/font.h" 12 #include "ui/gfx/gfx_export.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 GFX_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 font names, styles and size. 45 FontList(const std::vector<std::string>& font_names, 46 int font_style, 47 int font_size); 48 49 // Creates a font list from a Font vector. 50 // All fonts in this vector should have the same style and size. 51 explicit FontList(const std::vector<Font>& fonts); 52 53 // Creates a font list from a Font. 54 explicit FontList(const Font& font); 55 56 ~FontList(); 57 58 // Sets the description string for default FontList construction. If it's 59 // empty, FontList will initialize using the default Font constructor. 60 // 61 // The client code must call this function before any call of the default 62 // constructor. This should be done on the UI thread. 63 // 64 // ui::ResourceBundle may call this function more than once when UI language 65 // is changed. 66 static void SetDefaultFontDescription(const std::string& font_description); 67 68 // Returns a new FontList with the given |font_style| flags. 69 FontList DeriveFontList(int font_style) const; 70 71 // Returns a new FontList with the same font names and style but with the 72 // given font |size| in pixels. 73 FontList DeriveFontListWithSize(int size) const; 74 75 // Returns a new FontList with the same font names and style but resized. 76 // |size_delta| is the size in pixels to add to the current font size. 77 FontList DeriveFontListWithSizeDelta(int size_delta) const; 78 79 // Returns a new FontList with the same font names but resized and the given 80 // style. |size_delta| is the size in pixels to add to the current font size. 81 // |font_style| specifies the new style, which is a bitmask of the values: 82 // Font::BOLD, Font::ITALIC and Font::UNDERLINE. 83 FontList DeriveFontListWithSizeDeltaAndStyle(int size_delta, 84 int font_style) const; 85 86 // Returns the height of this font list, which is max(ascent) + max(descent) 87 // for all the fonts in the font list. 88 int GetHeight() const; 89 90 // Returns the baseline of this font list, which is max(baseline) for all the 91 // fonts in the font list. 92 int GetBaseline() const; 93 94 // Returns the cap height of this font list. 95 // Currently returns the cap height of the primary font. 96 int GetCapHeight() const; 97 98 // Returns the number of horizontal pixels needed to display |text|. 99 int GetStringWidth(const base::string16& text) const; 100 101 // Returns the expected number of horizontal pixels needed to display the 102 // specified length of characters. Call GetStringWidth() to retrieve the 103 // actual number. 104 int GetExpectedTextWidth(int length) const; 105 106 // Returns the |gfx::Font::FontStyle| style flags for this font list. 107 int GetFontStyle() const; 108 109 // Returns a string representing font names, styles, and size. If the FontList 110 // is initialized by a vector of Font, use the first font's style and size 111 // for the description. 112 const std::string& GetFontDescriptionString() const; 113 114 // Returns the font size in pixels. 115 int GetFontSize() const; 116 117 // Returns the Font vector. 118 const std::vector<Font>& GetFonts() const; 119 120 // Returns the first font in the list. 121 const Font& GetPrimaryFont() const; 122 123 private: 124 // Extracts common font height and baseline into |common_height_| and 125 // |common_baseline_|. 126 void CacheCommonFontHeightAndBaseline() const; 127 128 // Extracts font style and size into |font_style_| and |font_size_|. 129 void CacheFontStyleAndSize() const; 130 131 // A vector of Font. If FontList is constructed with font description string, 132 // |fonts_| is not initialized during construction. Instead, it is computed 133 // lazily when user asked to get the font vector. 134 mutable std::vector<Font> fonts_; 135 136 // A string representing font names, styles, and sizes. 137 // Please refer to the comments before class declaration for details on string 138 // format. 139 // If FontList is constructed with a vector of font, 140 // |font_description_string_| is not initialized during construction. Instead, 141 // it is computed lazily when user asked to get the font description string. 142 mutable std::string font_description_string_; 143 144 // The cached common height and baseline of the fonts in the font list. 145 mutable int common_height_; 146 mutable int common_baseline_; 147 148 // Cached font style and size. 149 mutable int font_style_; 150 mutable int font_size_; 151 }; 152 153 } // namespace gfx 154 155 #endif // UI_GFX_FONT_LIST_H_ 156