/*

* Copyright (c) 2009 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:  

*

*/

#ifndef CNTVIEWNAVIGATOR_H_

#define CNTVIEWNAVIGATOR_H_

#include <QObject>

#include <QStack>

#include "cntviewparameters.h"

/*!

 * Navigator keeps track on view history, the path that user has

 * gone throug. If back() is called, one step back view id

 * given, unless exception is set to current view id. In case of

 * exception, navigator goes back in history until the exception 

 * value is found. Note the difference between "back with exeception" vs.

 * "launching given view id" (next()). 

 *

 * Next goes one step forward and stores history. 

 * Navigator is implemented as stack of view ids.

 *

 */

class CntViewNavigator : public QObject

{

    Q_OBJECT

public:

    CntViewNavigator( QObject* aParent );

    ~CntViewNavigator();

public:

    /*!

     * Next view puts the given id as current view

     */

    void next( const CntViewParameters::ViewId& aId );

    /*!

     * Back view returns the previous view

     */

    const CntViewParameters::ViewId& back();

    /*!

     * Add exceptions to next/back mechanism. Function will use the aBack argument

     * for previous view when aCurrent is the active view.

     */

    void addException( const CntViewParameters::ViewId& aCurrent, const CntViewParameters::ViewId& aBack );

    void removeException( const CntViewParameters::ViewId& aCurrent );

private:

    QStack<CntViewParameters::ViewId> iViewStack;

    QMap< CntViewParameters::ViewId, CntViewParameters::ViewId> iExceptions;

    CntViewParameters::ViewId iTop;

};

#endif /* CNTVIEWNAVIGATOR_H_ */