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