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