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30
31#ifndef UniscribeHelperTextRun_h
32#define UniscribeHelperTextRun_h
33
34#include "UniscribeHelper.h"
35
36namespace WebCore {
37
38class Font;
39class TextRun;
40
41// Wrapper around the Uniscribe helper that automatically sets it up with the
42// WebKit types we supply.
43class UniscribeHelperTextRun : public UniscribeHelper {
44public:
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
59protected:
60    virtual void tryToPreloadFont(HFONT);
61
62private:
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