/*

* Copyright (c) 2007-2008 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:  event handler class

*

*/

#ifndef C_HNEVENTHANDLER_H

#define C_HNEVENTHANDLER_H

#include <liwcommon.h>

class CHnMetaDataModel;

class CHnMdAction;

class MLiwInterface;

class CLiwServiceHandler;

class CLiwGenericParamList;

class CHnMdBaseKey;

class TLiwVariant;

class CHnMdItem;

class CHnActionModel;

class MHnMdModelEventObserver;

class CHnServiceHandler;

class MHnControllerInterface;

/**

 *  Event handler class.

 * 

 *  Event Handler is designed to handle events. 

 *  It reveives an event id from the UI, 

 *  mapps this event into an appropriate action, 

 *  and runs this action.

 *

 *  @lib hnpresentationmodel

 *  @since S60 5.0

 *  @ingroup group_hnpresentationmodel

 */

NONSHARABLE_CLASS(CHnEventHandler) : public CBase, public MLiwNotifyCallback

{

public: // Constructors and destructor

   /**

    * Two-phased constructor.

    * 

    * @since S60 5.0

    * @param aModelObserver Model event observer.

    * @param aController Interface enabling to issues request to Hn engine.    

    * @return Fully constructed object.

    */

    static CHnEventHandler* NewL( MHnMdModelEventObserver& aModelObserver,

            MHnControllerInterface& aController );

   /**

    * Two-phased constructor.

    * 

    * @since S60 5.0

    * @param aModelObserver Model event observer.

    * @param aController Interface enabling to issues request to Hn engine.

    * @return Fully constructed object.

    */

    static CHnEventHandler* NewLC( MHnMdModelEventObserver& aModelObserver,

            MHnControllerInterface& aController);

   /**

    * Destructor.

    * 

    * @since S60 5.0

    */

    ~CHnEventHandler();    

    /**

     * Executes the action that was found in the Model.

     * 

     * @since S60 v3.2

     * @see CHnActionModel

     * @param aActionModel A pointer to the object of the CHnActionModel class.

     * @return Error code. KErrNone in case of a correct execution (even if

               given action was not found). KErrNotFound in case of incorrect

               action parameters.

     */

    IMPORT_C TInt ExecuteActionL( CHnActionModel* aActionModel );

private:

   /**

    * Constructor for performing 1st stage construction

    * 

    * @since S60 5.0

    * @param aModelObserver A model event observer reference.

    * @param aController A HH controller reference.

    */

    CHnEventHandler( MHnMdModelEventObserver& aModelObserver,

                     MHnControllerInterface& aController );

   /**

    * EPOC default constructor for performing 2nd stage construction

    * 

    * @since S60 5.0

    */

    void ConstructL();

    /**

     * Notifies UI about actions that can be passed back to the UI,

     * i.e. openning nested suites, widget change.

     * 

     * @since S60 5.0

     * @param aActionModel Model of the action.

     * @return Error code

     */

    TInt ExecuteInternalActionL( CHnActionModel* aActionModel );

    /**

     * Executes action from Extension Manager.

     * 

     * @since S60 v5.0

     * @param aActionModel Model of the action.

     * @return Error code

     */

    TInt ExecuteExtensionManagerActionL( CHnActionModel* aActionModel );

    /**

     * Uses default mechanism to execute an action.

     * 

     * @since S60 v5.0

     * @param aActionModel Model of the action.

     * @return Error code

     */

    TInt ExecuteStandardActionL( CHnActionModel* aActionModel );

    /**

     * Extracts extension uid from the action.

     * 

     * @since S60 v5.0

     * @param aInterface Interface to invoke action on.

     * @param aUid The resulting UID.

     * @return Error code

     */

    TInt ExtractUidFromActionL( const TDesC8& aInterface, TUid& aUid );

// from MLiwNotifyCallback

public :    

    /**

     * Handles notification.

     * 

     * @param aCmdId The Id of the command triggered.

     * @param aEventId The Id of the event.

     * @param aEventParamList Parameters to event.

     * @param aInParamList Input parameter list.

     * 

     * @return Error code.

     */

    TInt HandleNotifyL( TInt aCmdId, TInt aEventId,

            CLiwGenericParamList& aEventParamList,

            const CLiwGenericParamList& aInParamList );

private: // data

    /**

     * Not own.

     * Reference to HnEngine - Event observer.

     */

    MHnMdModelEventObserver& iEventObserver;

    /**

     * Own.

     */

    CHnServiceHandler* iServiceHandler;

    /**

     * Not own.

     * Reference to App UI - Event observer.

     */

    MHnControllerInterface& iControllerInterface;

    /**

     * ETrue if a standard asynchroneous action is being executed by

     * this event handler.

     */

    TBool iIsExecutingStandardAsyncAction;

};

#endif // C_HNEVENTHANDLER_H