Home | History | Annotate | Download | only in gfx 
      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 
     14 namespace gfx {
     15 
     16 // Internals of font_fallback_win.cc exposed for testing.
     17 namespace 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.
     24 void 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.
     30 void 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.
     35 class 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.
     84 bool 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