/*

* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:     Algorithms for Speech Synthesis

*

*/

#ifndef TTSHWDEVICE_H

#define TTSHWDEVICE_H

//  INCLUDES

#include <e32std.h>

#include <e32base.h>

#include <nssttscommon.h>

#include <asrshwdevice.h>

// FORWARD DECLARATIONS

class CTtsAlgorithm;

// CLASS DECLARATION

/**

*  Class to define callback functions

*

*  @lib asrsttshwdevice.lib

*  @since 2.8

*/

class MTtsHwDeviceObserver

    {

    public: // New functions

		/**

        * Called by the HW device when the synthesis has been completed.

        * @since 2.8

        * @param aStatus Error code, KErrNone if success

        * @return none

        */

		virtual void MthdTtsCompleted( TInt aStatus ) = 0;

		/**

        * Invoked by TTS HW Device when it needs a configuration data package.

        * @since 2.8

        * @param aPackageType Type identifier. 

        * @param aPackageID Identifier of package

        * @param aStartPosition Start index in bytes

        * @param aEndPosition End index in bytes. If the position is bigger 

        *         than the size of data package, the end part will be returned.

        * @return Data package in a buffer

        */

        virtual HBufC8* MthdoConfigurationData( TUint32 aPackageType, 

                                                TUint32 aPackageID, 

                                                TUint32 aStartPosition, 

                                                TUint32 aEndPosition) = 0;

		/**

        * Called by the HW device when custom command implementation wants to notify a client.

        * @since 2.8

        * @param aEvent Event code aStatus Error code, KErrNone if success.

        * @param aParameter Optional parameter 

        * @return none

        */

		virtual void MthdCustomEvent( TInt aEvent, 

                                      TInt aStatus, 

                                      const TDesC8& aParameter = KNullDesC8 ) = 0;

        /**

        * Called by the HW device when the HW device has synthesized a new audio buffer.

        * @since 2.8

        * @param aBuffer Synthesized audio buffer.

        * @return none

        */

        virtual void MthdProcessBuffer( const TDesC8& aBuffer ) = 0;

	};

/**

*  Class to provide speech synthesis

*

*  @lib asrsttshwdevice.lib

*  @since 2.8

*/

class CTtsHwDevice : public CASRSHwDevice

    {

    public: // Constructors and destructor

        /**

        * Two-phased constructor.

        * @param aObserver Observer which implements callback functions.

        * @param aSamplingRate Sampling rate for output audio

        * @param aBufferSize Buffer size for output audio

        */

        IMPORT_C static CTtsHwDevice* NewL( MTtsHwDeviceObserver& aObserver,

                                            TUint aSamplingRate, 

                                            TUint aBufferSize );

        /**

        * Destructor.

        */

        IMPORT_C virtual ~CTtsHwDevice();

    public: // New functions

        /**

        * Adds new style to the collection. If equal style exists already, new style is not added.

        * @since 2.8

        * @param aStyle Style to be added.

        * @return Identifier of added style. If equal style exists already, identifier to the old style will be returned.

        */

        IMPORT_C TTtsStyleID AddStyleL( const TTtsStyle& aStyle );

        /**

        * Analyses stucture of text and adds style information.

        * @since 2.8

        * @param aText Updates text object by dividing it into segments with new styles.

        * @return none

        */

        IMPORT_C void AnalyzeProsodyL( CTtsParsedText& aText );

        /**

        * Analyses stucture of text by finding paragraphs and sentences.

        * @since 2.8

        * @param aText Updates text object by segmenting it into paragraphs and sentences.

        * @return none

        */

        IMPORT_C void AnalyzeStructureL( CTtsParsedText& aText );

        /**

        * Notifies that the buffer has been processed

        * @since 2.8

        * @param aBuffer The buffer which has been processed

        * @return none

        */

        IMPORT_C void BufferProcessed( const TDesC8& aBuffer );

        /**

        * Deletes style.

        * @since 2.8

        * @param aStyleID Identifier of style to be deleted.

        * @return none

        */

        IMPORT_C void DeleteStyleL( TTtsStyleID aStyleID );

        /**

        * Gives current position of synthesizing.

        * @since 2.8

        * @param aTime Time of the synthesizing position.

        * @return none

        */

        IMPORT_C void GetPositionL( TTimeIntervalMicroSeconds& aTime );

        /**

        * Gives current position of synthesizing.

        * @since 2.8

        * @param aSegment The segment being synthesizing

        * @param aWordIndex The index of word being synthesizing

        * @return none

        */

        IMPORT_C void GetPositionL( TTtsSegment& aSegment, 

                                    TInt& aWordIndex );

        /**

        * Ask if a language is supported or not.

        * @since 2.8

        * @param aLanguage Synthesizing language.

        * @return ETrue language is supported otherwise EFalse

        */

        IMPORT_C TBool IsLanguageSupported( TLanguage aLanguage );

        /**

        * Gives number of styles.

        * @since 2.8

        * @param none

        * @return Number of styles.

        */

        IMPORT_C TUint16 NumberOfStyles() const;

        /**

        * Pauses synthesizing. 

        * @since 2.8

        * @param none

        * @return none

        */

        IMPORT_C void Pause();

        /**

        * Prepares for synthesizing.

        * @since 2.8

        * @param aStream Stream to be synthesized.

        * @return none

        */

        IMPORT_C void PrimeSynthesisL( MTtsSegmentStream& aStream );

        /**

        * Prepares for synthesizing. 

        * @since 2.8

        * @param aText Text containing segments to be synthesized.

        * @return none

        */

        IMPORT_C void PrimeSynthesisL( CTtsParsedText& aText );

        /**

        * Sets new position for synthesizing.

        * @since 2.8

        * @param aTime Time of the synthesizing postion.

        * @return none

        */

        IMPORT_C void SetPositionL( const TTimeIntervalMicroSeconds& aTime );

        /**

        * Sets new position for synthesizing.

        * @since 2.8

        * @param aSegment The segment being synthesizing

        * @param aWordIndex The index of word being synthesizing

        * @return none

        */

        IMPORT_C void SetPositionL( const TTtsSegment& aSegment, 

                                    TInt aWordIndex );

        /**

        * Stops synthesizing and releases resources of synthesizing. 

        * The method does nothing if already stopped.

        * @since 2.8

        * @param 

        * @return none

        */

        IMPORT_C void Stop();

        /**

        * Receives style information

        * @since 2.8

        * @param aStyleID Style identifier

        * @return Style

        */

        IMPORT_C TTtsStyle& StyleL( TTtsStyleID aStyleID );

        /**

        * Receives style information

        * @since 2.8

        * @param aIndex Index to style: 0..NumberOfStyles()

        * @return Style

        */

        IMPORT_C TTtsStyle& StyleL( TUint16 aIndex );

        /**

        * Starts waveform production. The synthesized audio buffers are send back 

        * to client using MthdProcessBuffer().

        * @since 2.8

        * @param none

        * @return none

        */

        IMPORT_C void SynthesizeL();

    private:

        /**

        * C++ default constructor.

        */

        CTtsHwDevice();

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL( MTtsHwDeviceObserver& aObserver,

                         TUint aSamplingRate, 

                         TUint aBufferSize );

    private: // Data

		// Actual algorithm where all processing happens

		CTtsAlgorithm* iAlgorithm;

		// Reserved pointer for future extension

        TAny* iReserved;

    };

#endif // TTSHWDEVICE_H   

// End of File