/*

* 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:  State machine

*

*/

#ifndef CSTATEMACHINE_H

#define CSTATEMACHINE_H

class CRequestsHandler;

class CEP0Reader;

class CEP0Writer;

/**

 *  State machine for the control transfers

 *  Switches usbdevcon states between Setup-Data-Status

 *

 *  @lib usbdevcon.lib

 *  @since S60 v.5.0 

 */

class CStateMachine : public CBase 

    {

public:

    /**  States */

    enum TState

    {

        ENoneState,     // State is not defined 

        ESetupStage,    // ready for getting control setup transaction

        EDataStage,     // reading data from host, in Data stage        

        EStatusStage    // waiting for Status transaction, after writing data to host

    };

     /**

     * Two-phased constructor.

     *

     * @since S60 v.5.0

     * @param aRequestHandler Handles requests

     * @param aLdd Link to LDD services

     * @return Constructed instance

     */ 

    static CStateMachine* NewL(CRequestsHandler& aRequestsHandler, RDevUsbcClient& aLdd);

    /**

    * Destructor.

    *

    * @since S60 v.5.0

    */

    virtual ~CStateMachine();

    /**

     * Call back from CEP0Reader

     *

     * @since S60 v.5.0

     * @param aBuffer Data read from EP0

     * @param aStatus status of Read request, completed

     */

    /**

     * Call back from CEP0Writer

     *

     * @since S60 v.5.0

     * @param aStatus status of Write request, completed

     */

    /**

     * Starts machine

     *

     * @since S60 v.5.0

     */

    /**

     * Stops machine

     *

     * @since S60 v.5.0

     */

    void Stop();

    /**

     * Machine is started

     *

     * @since S60 v.5.0

     * @return ETrue if state machine is started

     */

    TBool IsStarted() const;

private:

    /**

     * Default construction

     *

     * @since S60 v.5.0

     * @param aRequestHandler Handles requests

     * @param aLdd Link to LDD services

     */

    CStateMachine(CRequestsHandler& aRequestsHandler, RDevUsbcClient& aLdd);

    /**

     * Two-phased constructor.

     *

     * @since S60 v.5.0

     */

    void ConstructL();

    /**

     * Process setup packet

     *

     * @since S60 v.5.0

     * @param aSetupPacket Will be processed

     */

    /**

     * Checks wheather data required to be sent from host to device 

     *

     * @since S60 v.5.0

     * @param aSetupPacket Contains data direction bit, and length of data

     * @param aDataLength Length of data to be sent

     * @return ETrue If data stage is required

     */

    TBool IsDataFromHostRequired(const RBuf8& aSetupPacket, TUint& aDatalength) const;

    /**

     * Checks wheather data required to be sent from device to host

     *

     * @since S60 v.5.0

     * @param aSetupPacket Contains data direction bit, and length of data

     * @param aDataLength Length of data to be sent

     * @return ETrue If data stage is required

     */

    TBool IsDataFromDeviceRequired(const RBuf8& aSetupPacket, TUint& aDatalength) const;

private: // data

    /**

     * EP0 reader

     * Own.  

     */

    CEP0Reader* iEP0Reader;

    /**

     * EP0 writer

     * Own.  

     */

    CEP0Writer* iEP0Writer;

    /**

     * Requests handler

     * Not own.  

     */

    CRequestsHandler& iRequestsHandler;

    /**

     * LDD

     * Not own.  

     */

    RDevUsbcClient& iLdd;

    /**

     * State

     */

    TState iState;

    /**

     * Buffer to keep request, if needed to receive data from host in Data stage

     * In case if request require data to be send from device to host,

     * iBuffer keeps result of that request

     */

    RBuf8 iBuffer;

    };

#endif // CSTATEMACHINE_H