sl@0: 
sl@0: /*
sl@0:  *
sl@0:  * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #ifndef __THAILAYOUTENGINE_H
sl@0: #define __THAILAYOUTENGINE_H
sl@0: 
sl@0: #include "LETypes.h"
sl@0: #include "LEFontInstance.h"
sl@0: #include "LayoutEngine.h"
sl@0: 
sl@0: #include "ThaiShaping.h"
sl@0: 
sl@0: U_NAMESPACE_BEGIN
sl@0: 
sl@0: class LEGlyphStorage;
sl@0: 
sl@0: /**
sl@0:  * This class implements layout for the Thai script, using the ThaiShapingClass.
sl@0:  * All existing Thai fonts use an encoding which assigns character codes to all
sl@0:  * the variant forms needed to display accents and tone marks correctly in context.
sl@0:  * This class can deal with fonts using the Microsoft, Macintosh, and WorldType encodings.
sl@0:  *
sl@0:  * @internal
sl@0:  */
sl@0: class ThaiLayoutEngine : public LayoutEngine
sl@0: {
sl@0: public:
sl@0:     /**
sl@0:      * This constructs an instance of ThaiLayoutEngine for the given font, script and
sl@0:      * language. It examines the font, using LEFontInstance::canDisplay, to set fGlyphSet
sl@0:      * and fErrorChar. (see below)
sl@0:      *
sl@0:      * @param fontInstance - the font
sl@0:      * @param scriptCode - the script
sl@0:      * @param languageCode - the language
sl@0:      *
sl@0:      * @see LEFontInstance
sl@0:      * @see ScriptAndLanguageTags.h for script and language codes
sl@0:      *
sl@0:      * @internal
sl@0:      */
sl@0:     ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags);
sl@0: 
sl@0:     /**
sl@0:      * The destructor, virtual for correct polymorphic invocation.
sl@0:      *
sl@0:      * @internal
sl@0:      */
sl@0:     virtual ~ThaiLayoutEngine();
sl@0: 
sl@0:     /**
sl@0:      * ICU "poor man's RTTI", returns a UClassID for the actual class.
sl@0:      *
sl@0:      * @stable ICU 2.8
sl@0:      */
sl@0:     virtual UClassID getDynamicClassID() const;
sl@0: 
sl@0:     /**
sl@0:      * ICU "poor man's RTTI", returns a UClassID for this class.
sl@0:      *
sl@0:      * @stable ICU 2.8
sl@0:      */
sl@0:     static UClassID getStaticClassID();
sl@0: 
sl@0: protected:
sl@0:     /**
sl@0:      * A small integer indicating which Thai encoding
sl@0:      * the font uses.
sl@0:      *
sl@0:      * @see ThaiShaping
sl@0:      *
sl@0:      * @internal
sl@0:      */
sl@0:     le_uint8 fGlyphSet;
sl@0: 
sl@0:     /**
sl@0:      * The character used as a base for vowels and
sl@0:      * tone marks that are out of sequence. Usually
sl@0:      * this will be Unicode 0x25CC, if the font can
sl@0:      * display it.
sl@0:      *
sl@0:      * @see ThaiShaping
sl@0:      *
sl@0:      * @internal
sl@0:      */
sl@0:     LEUnicode fErrorChar;
sl@0: 
sl@0:     /**
sl@0:      * This method performs Thai layout. It calls ThaiShaping::compose to
sl@0:      * generate the correct contextual character codes, and then calls
sl@0:      * mapCharsToGlyphs to generate the glyph indices.
sl@0:      *
sl@0:      * Input parameters:
sl@0:      * @param chars - the input character context
sl@0:      * @param offset - the index of the first character to process
sl@0:      * @param count - the number of characters to process
sl@0:      * @param max - the number of characters in the input context
sl@0:      * @param rightToLeft - <code>TRUE</code> if the text is in a right to left directional run
sl@0:      * @param glyphStorage - the glyph storage object. The glyph and char index arrays will be set.
sl@0:      *
sl@0:      * Output parameters:
sl@0:      * @param success - set to an error code if the operation fails
sl@0:      *
sl@0:      * @return the number of glyphs in the glyph index array
sl@0:      *
sl@0:      * @see ThaiShaping
sl@0:      *
sl@0:      * @internal
sl@0:      */
sl@0:     virtual le_int32 computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
sl@0:         LEGlyphStorage &glyphStorage, LEErrorCode &success);
sl@0: 
sl@0: };
sl@0: 
sl@0: U_NAMESPACE_END
sl@0: #endif
sl@0: