/*

  * HanLayoutEngine.h: OpenType processing for Han fonts.

  *

  * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved.

  */

 #ifndef __HANLAYOUTENGINE_H

 #define __HANLAYOUTENGINE_H

 #include "LETypes.h"

 #include "LEFontInstance.h"

 #include "LayoutEngine.h"

 #include "OpenTypeLayoutEngine.h"

 #include "GlyphSubstitutionTables.h"

 U_NAMESPACE_BEGIN

 class LEGlyphStorage;

 /**

  * This class implements OpenType layout for Han fonts. It overrides

  * the characerProcessing method to assign the correct OpenType feature

  * tags for the CJK language-specific forms.

  *

  * @internal

  */

 class HanOpenTypeLayoutEngine : public OpenTypeLayoutEngine

 {

 public:

     /**

      * This is the main constructor. It constructs an instance of HanOpenTypeLayoutEngine for

      * a particular font, script and language. It takes the GSUB table as a parameter since

      * LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has a

      * Han OpenType font.

      *

      * @param fontInstance - the font

      * @param scriptCode - the script

      * @param langaugeCode - the language

      * @param gsubTable - the GSUB table

      *

      * @see LayoutEngine::layoutEngineFactory

      * @see OpenTypeLayoutEngine

      * @see ScriptAndLangaugeTags.h for script and language codes

      *

      * @internal

      */

     HanOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,

                             le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable);

     /**

      * The destructor, virtual for correct polymorphic invocation.

      *

      * @internal

      */

     virtual ~HanOpenTypeLayoutEngine();

     /**

      * ICU "poor man's RTTI", returns a UClassID for the actual class.

      *

      * @stable ICU 2.8

      */

     virtual UClassID getDynamicClassID() const;

     /**

      * ICU "poor man's RTTI", returns a UClassID for this class.

      *

      * @stable ICU 2.8

      */

     static UClassID getStaticClassID();

 protected:

     /**

      * This method does Han OpenType character processing. It assigns the OpenType feature

      * tags to the characters to generate the correct language-specific variants.

      *

      * Input parameters:

      * @param chars - the input character context

      * @param offset - the index of the first character to process

      * @param count - the number of characters to process

      * @param max - the number of characters in the input context

      * @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run

      * @param glyphStorage - the object holding the glyph storage. The char index and auxillary data arrays will be set.

      *

      * Output parameters:

      * @param outChars - the output character arrayt

      * @param charIndices - the output character index array

      * @param featureTags - the output feature tag array

      * @param success - set to an error code if the operation fails

      *

      * @return the output character count

      *

      * @internal

      */

     virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,

             LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success);

 };

 U_NAMESPACE_END

 #endif