Home | History | Annotate | Download | only in chromium 
      1 /*
      2  * Copyright (c) 2006, 2007, 2008, 2009, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef UniscribeHelperTextRun_h
     32 #define UniscribeHelperTextRun_h
     33 
     34 #include "UniscribeHelper.h"
     35 
     36 namespace WebCore {
     37 
     38 class Font;
     39 class TextRun;
     40 
     41 // Wrapper around the Uniscribe helper that automatically sets it up with the
     42 // WebKit types we supply.
     43 class UniscribeHelperTextRun : public UniscribeHelper {
     44 public:
     45     // Regular constructor used for WebCore text run processing.
     46     UniscribeHelperTextRun(const TextRun&, const Font&);
     47 
     48     // Constructor with the same interface as the gfx::UniscribeState. Using
     49     // this constructor will not give you font fallback, but it will provide
     50     // the ability to load fonts that may not be in the OS cache
     51     // ("TryToPreloadFont") if the caller does not have a TextRun/Font.
     52     UniscribeHelperTextRun(const wchar_t* input,
     53                            int inputLength,
     54                            bool isRtl,
     55                            HFONT hfont,
     56                            SCRIPT_CACHE*,
     57                            SCRIPT_FONTPROPERTIES*);
     58 
     59 protected:
     60     virtual void tryToPreloadFont(HFONT);
     61 
     62 private:
     63     // This function retrieves the Windows font data (HFONT, etc) for the next
     64     // WebKit font in the list. If the font data corresponding to font_index_
     65     // has been obtained before, returns the values stored in our internal
     66     // vectors (hfonts_, etc).  Otherwise, it gets next SimpleFontData from
     67     // WebKit and adds them to in hfonts_ and friends so that font data can be
     68     // returned quickly next time they're requested.
     69     virtual bool nextWinFontData(HFONT*, SCRIPT_CACHE**, SCRIPT_FONTPROPERTIES**, int* ascent);
     70     virtual void resetFontIndex();
     71 
     72     // Reference to WebKit::Font that contains all the information about fonts
     73     // we can use to render this input run of text.  It is used in
     74     // NextWinFontData to retrieve Windows font data for a series of
     75     // non-primary fonts.
     76     //
     77     // This pointer can be NULL for no font fallback handling.
     78     const Font* m_font;
     79 
     80     // It's rare that many fonts are listed in stylesheets.
     81     // Four would be large enough in most cases.
     82     const static size_t kNumberOfFonts = 4;
     83 
     84     // These vectors are used to store Windows font data for non-primary fonts.
     85     Vector<HFONT, kNumberOfFonts> m_hfonts;
     86     Vector<SCRIPT_CACHE*, kNumberOfFonts> m_scriptCaches;
     87     Vector<SCRIPT_FONTPROPERTIES*, kNumberOfFonts> m_fontProperties;
     88     Vector<int, kNumberOfFonts> m_ascents;
     89 
     90     // Index of the fallback font we're currently using for NextWinFontData.
     91     int m_fontIndex;
     92 };
     93 
     94 }  // namespace WebCore
     95 
     96 #endif  // UniscribeHelperTextRun_h
     97