/*

* Copyright (c) 2006 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:  Base class for states

*

*/

#ifndef CVTENGSTATEBASE_H

#define CVTENGSTATEBASE_H

//  INCLUDES

#include <e32base.h>

#include "vtengcommands.h"

#include "CVtEngStateManager.h"

#include "CVtEngEventManager.h"

#include "CVtEngMediaHandler.h"

#include "CVtEngSessionHandler.h"

#include "CVtEngOperation.h"

#include "CVtEngSettings.h"

#include "VtEngUtils.h"

// FORWARD DECLARATIONS

class CVtEngSessionHandler;

class CVtEngMediaHandler;

class CVtEngAudioHandler;

// CLASS DECLARATION

/**

*  State base class

*  @lib videoteleng

*  @since 2.6

*/

NONSHARABLE_CLASS( CVtEngStateBase ) : public CBase

    {

    public:  // Constructors and destructor

        /**

        * Destructor.

        */

        virtual ~CVtEngStateBase();

    public: // New functions

        /**

        * Updates state. May result to state transition

        */

        virtual void UpdateL() = 0;

        /**

        * Checks if a command is valid in current state.

        * @param aCommandId command to be validated

        * @return ETrue if command is valid.

        */

        virtual TBool ValidateCommand(

            const TVtEngCommandId aCommandId );

        /**

        * Handles an operation. Base class method is empty

        * and derived classes may handle the operation if applicable.

        * @param aOp operation to be handled

        * @return ETrue if handled

        */

        virtual TBool HandleL( CVtEngOperation& aOp );

        /**

        * Returns session handler.

        * @return reference to session handler

        */

        CVtEngSessionHandler& SessionHandler();

        /**

        * Returns media handler.

        * @return reference to media handler

        */

        CVtEngMediaHandler& MediaHandler();

        /**

        * Returns audio handler.

        * @return reference to audio handler

        */

        CVtEngAudioHandler& AudioHandler();

        /**

        * Creates new state if needed.

        * @return new state or NULL

        */

        CVtEngStateBase* NewStateL( 

            const MVtEngSessionInfo::TSessionState aState );

        virtual MVtEngSessionInfo::TSessionState State() const = 0;

    public: // New functions 

        /**

        * Sets new current state. 

        * @param aOldState old state.

        */

        void OpenL( CVtEngStateBase* aOldState );

        /**

        * For derived classes to handle state change

        */

        virtual void DoOpenL( ) = 0;

        /**

        * State uninitialization.

        */

        virtual void Close();

    protected: // new functions

        /**

        * Saves configuration to settings for later

        * usage.

        */

        void SaveToSettingsL( CVtEngOperation& aOp );

        /**

        * Notifies state change to event manager.

        * @param aNewState new session state.

        */

        void NotifyStateChange( MVtEngSessionInfo::TSessionState aNewState );

        /**

        * Saves video state to settings. Used e.g. when video can not be 

        * started in current state.

        * @param aEnabled video is enabled

        */

        void SetVideoEnabled( TBool aEnabled );

        /**

        * Goes to disconnecting or idle state if needed.

        * @return state object if transition is required.

        */

        //CVtEngStateBase* DisconnectingOrIdleStateL();

        /**

        * Creates negotiating state if bearer state is connected

        * and pv state is ESetup, and UI has indicated state changte

        * is permitted.

        * @return negotiating state object or NULL

        */

        CVtEngStateBase* NegotiatingOrConnectedStateL( 

            TBool aAcceptOnlyNegotiating = EFalse );

        /**

        * Saves video state to settings. Used e.g. when video can not be 

        * started in current state.

        * @param aEnabled video is enabled

        */

        void TerminateSessionL( CVtEngOperation& aOp );

    protected:

        /**

        * C++ constructor.

        */

        CVtEngStateBase( 

            CVtEngStateManager& aStateManager,

            CVtEngEventManager& aEventManager );

    protected:  // Data

        // State manager

        CVtEngStateManager& iStateManager;

        // Event manager

        CVtEngEventManager& iEventManager;

    private:

    };

#endif      // CVTENGSTATEBASE_H

// End of File