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 "base/memory/ref_counted.h" 12 #include "ui/gfx/font.h" 13 #include "ui/gfx/gfx_export.h" 14 15 namespace gfx { 16 17 class FontListImpl; 18 19 // FontList represents a list of fonts and provides metrics which are common 20 // in the fonts. FontList is copyable and it's quite cheap to copy. 21 // 22 // The format of font description string complies with that of Pango detailed at 23 // http://developer.gnome.org/pango/stable/pango-Fonts.html#pango-font-description-from-string 24 // The format is "<FONT_FAMILY_LIST>,[STYLES] <SIZE>" where 25 // FONT_FAMILY_LIST is a comma-separated list of font family names, 26 // STYLES is a space-separated list of style names ("Bold" and "Italic"), 27 // SIZE is a font size in pixel with the suffix "px". 28 // Here are examples of font description string: 29 // "Arial, Helvetica, Bold Italic 14px" 30 // "Arial, 14px" 31 class GFX_EXPORT FontList { 32 public: 33 // Creates a font list with default font names, size and style, which are 34 // specified by SetDefaultFontDescription(). 35 FontList(); 36 37 // Creates a font list that is a clone of another font list. 38 FontList(const FontList& other); 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 // Copies the given font list into this object. 59 FontList& operator=(const FontList& other); 60 61 // Sets the description string for default FontList construction. If it's 62 // empty, FontList will initialize using the default Font constructor. 63 // 64 // The client code must call this function before any call of the default 65 // constructor. This should be done on the UI thread. 66 // 67 // ui::ResourceBundle may call this function more than once when UI language 68 // is changed. 69 static void SetDefaultFontDescription(const std::string& font_description); 70 71 // Returns a new FontList with the same font names but resized and the given 72 // style. |size_delta| is the size in pixels to add to the current font size. 73 // |font_style| specifies the new style, which is a bitmask of the values: 74 // Font::BOLD, Font::ITALIC and Font::UNDERLINE. 75 FontList Derive(int size_delta, int font_style) const; 76 77 // Returns a new FontList with the same font names and style but resized. 78 // |size_delta| is the size in pixels to add to the current font size. 79 FontList DeriveWithSizeDelta(int size_delta) const; 80 81 // Returns a new FontList with the same font names and size but the given 82 // style. |font_style| specifies the new style, which is a bitmask of the 83 // values: Font::BOLD, Font::ITALIC and Font::UNDERLINE. 84 FontList DeriveWithStyle(int font_style) const; 85 86 // Shrinks the font size until the font list fits within |height| while 87 // having its cap height vertically centered. Returns a new FontList with 88 // the correct height. 89 // 90 // The expected layout: 91 // +--------+-----------------------------------------------+------------+ 92 // | | y offset | space | 93 // | +--------+-------------------+------------------+ above | 94 // | | | | internal leading | cap height | 95 // | box | font | ascent (baseline) +------------------+------------+ 96 // | height | height | | cap height | 97 // | | |-------------------+------------------+------------+ 98 // | | | descent (height - baseline) | space | 99 // | +--------+--------------------------------------+ below | 100 // | | space at bottom | cap height | 101 // +--------+-----------------------------------------------+------------+ 102 // Goal: 103 // center of box height == center of cap height 104 // (i.e. space above cap height == space below cap height) 105 // Restrictions: 106 // y offset >= 0 107 // space at bottom >= 0 108 // (i.e. Entire font must be visible inside the box.) 109 gfx::FontList DeriveWithHeightUpperBound(int height) const; 110 111 // Returns the height of this font list, which is max(ascent) + max(descent) 112 // for all the fonts in the font list. 113 int GetHeight() const; 114 115 // Returns the baseline of this font list, which is max(baseline) for all the 116 // fonts in the font list. 117 int GetBaseline() const; 118 119 // Returns the cap height of this font list. 120 // Currently returns the cap height of the primary font. 121 int GetCapHeight() const; 122 123 // Returns the expected number of horizontal pixels needed to display the 124 // specified length of characters. Call GetStringWidth() to retrieve the 125 // actual number. 126 int GetExpectedTextWidth(int length) const; 127 128 // Returns the |gfx::Font::FontStyle| style flags for this font list. 129 int GetFontStyle() const; 130 131 // Returns a string representing font names, styles, and size. If the FontList 132 // is initialized by a vector of Font, use the first font's style and size 133 // for the description. 134 const std::string& GetFontDescriptionString() const; 135 136 // Returns the font size in pixels. 137 int GetFontSize() const; 138 139 // Returns the Font vector. 140 const std::vector<Font>& GetFonts() const; 141 142 // Returns the first font in the list. 143 const Font& GetPrimaryFont() const; 144 145 private: 146 explicit FontList(FontListImpl* impl); 147 148 static const scoped_refptr<FontListImpl>& GetDefaultImpl(); 149 150 scoped_refptr<FontListImpl> impl_; 151 }; 152 153 } // namespace gfx 154 155 #endif // UI_GFX_FONT_LIST_H_ 156