1// Copyright 2014 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_IMPL_H_
6#define UI_GFX_FONT_LIST_IMPL_H_
7
8#include <string>
9#include <vector>
10
11#include "base/memory/ref_counted.h"
12
13namespace gfx {
14
15class Font;
16
17// FontListImpl is designed to provide the implementation of FontList and
18// intended to be used only from FontList.  You must not use this class
19// directly.
20//
21// FontListImpl represents a list of fonts either in the form of Font vector or
22// in the form of a string representing font names, styles, and size.
23//
24// FontListImpl could be initialized either way without conversion to the other
25// form. The conversion to the other form is done only when asked to get the
26// other form.
27//
28// For the format of font description string, see font_list.h for details.
29class FontListImpl : public base::RefCounted<FontListImpl> {
30 public:
31  // Creates a font list from a string representing font names, styles, and
32  // size.
33  explicit FontListImpl(const std::string& font_description_string);
34
35  // Creates a font list from font names, styles and size.
36  FontListImpl(const std::vector<std::string>& font_names,
37               int font_style,
38               int font_size);
39
40  // Creates a font list from a Font vector.
41  // All fonts in this vector should have the same style and size.
42  explicit FontListImpl(const std::vector<Font>& fonts);
43
44  // Creates a font list from a Font.
45  explicit FontListImpl(const Font& font);
46
47  // Returns a new FontListImpl with the same font names but resized and the
48  // given style. |size_delta| is the size in pixels to add to the current font
49  // size. |font_style| specifies the new style, which is a bitmask of the
50  // values: Font::BOLD, Font::ITALIC and Font::UNDERLINE.
51  FontListImpl* Derive(int size_delta, int font_style) const;
52
53  // Returns the height of this font list, which is max(ascent) + max(descent)
54  // for all the fonts in the font list.
55  int GetHeight() const;
56
57  // Returns the baseline of this font list, which is max(baseline) for all the
58  // fonts in the font list.
59  int GetBaseline() const;
60
61  // Returns the cap height of this font list.
62  // Currently returns the cap height of the primary font.
63  int GetCapHeight() const;
64
65  // Returns the expected number of horizontal pixels needed to display the
66  // specified length of characters. Call GetStringWidth() to retrieve the
67  // actual number.
68  int GetExpectedTextWidth(int length) const;
69
70  // Returns the |gfx::Font::FontStyle| style flags for this font list.
71  int GetFontStyle() const;
72
73  // Returns a string representing font names, styles, and size. If the
74  // FontListImpl is initialized by a vector of Font, use the first font's style
75  // and size for the description.
76  const std::string& GetFontDescriptionString() const;
77
78  // Returns the font size in pixels.
79  int GetFontSize() const;
80
81  // Returns the Font vector.
82  const std::vector<Font>& GetFonts() const;
83
84  // Returns the first font in the list.
85  const Font& GetPrimaryFont() const;
86
87 private:
88  friend class base::RefCounted<FontListImpl>;
89
90  ~FontListImpl();
91
92  // Extracts common font height and baseline into |common_height_| and
93  // |common_baseline_|.
94  void CacheCommonFontHeightAndBaseline() const;
95
96  // Extracts font style and size into |font_style_| and |font_size_|.
97  void CacheFontStyleAndSize() const;
98
99  // A vector of Font. If FontListImpl is constructed with font description
100  // string, |fonts_| is not initialized during construction. Instead, it is
101  // computed lazily when user asked to get the font vector.
102  mutable std::vector<Font> fonts_;
103
104  // A string representing font names, styles, and sizes.
105  // Please refer to the comments before class declaration for details on string
106  // format.
107  // If FontListImpl is constructed with a vector of font,
108  // |font_description_string_| is not initialized during construction. Instead,
109  // it is computed lazily when user asked to get the font description string.
110  mutable std::string font_description_string_;
111
112  // The cached common height and baseline of the fonts in the font list.
113  mutable int common_height_;
114  mutable int common_baseline_;
115
116  // Cached font style and size.
117  mutable int font_style_;
118  mutable int font_size_;
119};
120
121}  // namespace gfx
122
123#endif  // UI_GFX_FONT_LIST_IMPL_H_
124