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      1 /*
      2  *
      3  * (C) Copyright IBM Corp.  and others 1998-2014 - All Rights Reserved
      4  *
      5  */
      6 
      7 #ifndef __GXLAYOUTENGINE2_H
      8 #define __GXLAYOUTENGINE2_H
      9 
     10 #include "LETypes.h"
     11 #include "LayoutEngine.h"
     12 
     13 #include "MorphTables.h"
     14 
     15 U_NAMESPACE_BEGIN
     16 
     17 class LEFontInstance;
     18 class LEGlyphStorage;
     19 
     20 /**
     21  * This class implements layout for QuickDraw GX or Apple Advanced Typograyph (AAT)
     22  * fonts. A font is a GX or AAT font if it contains a 'mort' table. See Apple's
     23  * TrueType Reference Manual (http://fonts.apple.com/TTRefMan/index.html) for details.
     24  * Information about 'mort' tables is in the chapter titled "Font Files."
     25  *
     26  * @internal
     27  */
     28 class GXLayoutEngine2 : public LayoutEngine
     29 {
     30 public:
     31     /**
     32      * This is the main constructor. It constructs an instance of GXLayoutEngine for
     33      * a particular font, script and language. It takes the 'mort' table as a parameter since
     34      * LayoutEngine::layoutEngineFactory has to read the 'mort' table to know that it has a
     35      * GX font.
     36      *
     37      * Note: GX and AAT fonts don't contain any script and language specific tables, so
     38      * the script and language are ignored.
     39      *
     40      * @param fontInstance - the font
     41      * @param scriptCode - the script
     42      * @param langaugeCode - the language
     43      * @param morphTable - the 'mort' table
     44      * @param success - set to an error code if the operation fails
     45      *
     46      * @see LayoutEngine::layoutEngineFactory
     47      * @see ScriptAndLangaugeTags.h for script and language codes
     48      *
     49      * @internal
     50      */
     51     GXLayoutEngine2(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, const LEReferenceTo<MorphTableHeader2> &morphTable, le_int32 typoFlags, LEErrorCode &success);
     52 
     53     /**
     54      * The destructor, virtual for correct polymorphic invocation.
     55      *
     56      * @internal
     57      */
     58     virtual ~GXLayoutEngine2();
     59 
     60     /**
     61      * ICU "poor man's RTTI", returns a UClassID for the actual class.
     62      *
     63      * @deprecated ICU 54. See {@link icu::LayoutEngine}
     64      */
     65     virtual UClassID getDynamicClassID() const;
     66 
     67     /**
     68      * ICU "poor man's RTTI", returns a UClassID for this class.
     69      *
     70      * @deprecated ICU 54. See {@link icu::LayoutEngine}
     71      */
     72     static UClassID getStaticClassID();
     73 
     74 protected:
     75 
     76     /**
     77      * The address of the 'mort' table
     78      *
     79      * @internal
     80      */
     81     const LEReferenceTo<MorphTableHeader2> fMorphTable;
     82 
     83     /**
     84      * This method does GX layout using the font's 'mort' table. It converts the
     85      * input character codes to glyph indices using mapCharsToGlyphs, and then
     86      * applies the 'mort' table.
     87      *
     88      * Input parameters:
     89      * @param chars - the input character context
     90      * @param offset - the index of the first character to process
     91      * @param count - the number of characters to process
     92      * @param max - the number of characters in the input context
     93      * @param rightToLeft - <code>TRUE</code> if the text is in a right to left directional run
     94      * @param glyphStorage - the glyph storage object. The glyph and char index arrays will be set.
     95      *
     96      * Output parameters:
     97      * @param success - set to an error code if the operation fails
     98      *
     99      * @return the number of glyphs in the glyph index array
    100      *
    101      * @internal
    102      */
    103     virtual le_int32 computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
    104         LEGlyphStorage &glyphStorage, LEErrorCode &success);
    105 
    106     /**
    107      * This method adjusts the glyph positions using the font's
    108      * 'kern', 'trak', 'bsln', 'opbd' and 'just' tables.
    109      *
    110      * Input parameters:
    111      * @param glyphStorage - the object holding the glyph storage. The positions will be updated as needed.
    112      *
    113      * Output parameters:
    114      * @param success - set to an error code if the operation fails
    115      *
    116      * @internal
    117      */
    118     virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
    119                                       LEGlyphStorage &glyphStorage, LEErrorCode &success);
    120 
    121 };
    122 
    123 U_NAMESPACE_END
    124 #endif
    125 
    126