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_FALLBACK_WIN_H_
6#define UI_GFX_FONT_FALLBACK_WIN_H_
7
8#include <string>
9#include <vector>
10
11#include "ui/gfx/font.h"
12#include "ui/gfx/font_fallback.h"
13
14namespace gfx {
15
16// Internals of font_fallback_win.cc exposed for testing.
17namespace internal {
18
19// Parses comma separated SystemLink |entry|, per the format described here:
20// http://msdn.microsoft.com/en-us/goglobal/bb688134.aspx
21//
22// Sets |filename| and |font_name| respectively. If a field is not present
23// or could not be parsed, the corresponding parameter will be cleared.
24void GFX_EXPORT ParseFontLinkEntry(const std::string& entry,
25                                  std::string* filename,
26                                  std::string* font_name);
27
28// Parses a font |family| in the format "FamilyFoo & FamilyBar (TrueType)".
29// Splits by '&' and strips off the trailing parenthesized expression.
30void GFX_EXPORT ParseFontFamilyString(const std::string& family,
31                                     std::vector<std::string>* font_names);
32
33// Iterator over linked fallback fonts for a given font. The linked font chain
34// comes from the Windows registry, but gets cached between uses.
35class GFX_EXPORT LinkedFontsIterator {
36 public:
37  // Instantiates the iterator over the linked font chain for |font|. The first
38  // item will be |font| itself.
39  explicit LinkedFontsIterator(Font font);
40  virtual ~LinkedFontsIterator();
41
42  // Sets the font that would be returned by the next call to |NextFont()|,
43  // useful for inserting one-time entries into the iterator chain.
44  void SetNextFont(Font font);
45
46  // Gets the next font in the link chain, if available, and increments the
47  // iterator. Returns |true| on success or |false| if the iterator is past
48  // last item (in that case, the value of |font| should not be used). If
49  // |SetNextFont()| was called, returns the font set that way and clears it.
50  bool NextFont(Font* font);
51
52 protected:
53  // Retrieves the list of linked fonts. Protected and virtual so that it may
54  // be overridden by tests.
55  virtual const std::vector<Font>* GetLinkedFonts() const;
56
57 private:
58  // Original font whose linked fonts are being iterated over.
59  Font original_font_;
60
61  // Font that was set via |SetNextFont()|.
62  Font next_font_;
63
64  // Indicates whether |SetNextFont()| was called.
65  bool next_font_set_;
66
67  // The font most recently returned by |NextFont()|.
68  Font current_font_;
69
70  // List of linked fonts; weak pointer.
71  const std::vector<Font>* linked_fonts_;
72
73  // Index of the current entry in the |linked_fonts_| list.
74  size_t linked_font_index_;
75
76  DISALLOW_COPY_AND_ASSIGN(LinkedFontsIterator);
77};
78
79}  // namespace internal
80
81// Finds a fallback font to render the specified |text| with respect to an
82// initial |font|. Returns the resulting font via out param |result|. Returns
83// |true| if a fallback font was found.
84bool GetUniscribeFallbackFont(const Font& font,
85                              const wchar_t* text,
86                              int text_length,
87                              Font* result);
88
89}  // namespace gfx
90
91#endif  // UI_GFX_FONT_FALLBACK_WIN_H_
92