/*

* Copyright (c) 2002 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:  Declaration of class CBrowserCommsModel.

*

*

*/

#ifndef BROWSER_COMMS_MODEL_H

#define BROWSER_COMMS_MODEL_H

//  INCLUDES

#include <e32base.h>

#include <ActiveApDb.h>

#include "CommsModel.h"

// FORWARD DECLARATION

// class CApListItem;

class CApListItemList;

// CLASS DECLARATION

/**

*  Comms model for the Browser.

*  Provides CommsDb / AP database handling. Because querying AP-s is slow, but

*  there should not be many of them, this class keeps a cached copy of AP-s.

*  AP db is observed, and the cached list of AP-s is kept up to date.

*  However, if database changes but we cannot get new data (database locked

*  etc., the cached list is kept (until we can get the new data successfully)).

*

*  @lib Browser.app

*  @since Series 60 1.2

*/

class CBrowserCommsModel:

                public CBase, public MCommsModel, public MActiveApDbObserver

	{

	public:     // construction

        /**

        * Two-phased constructor. Leaves on failure.

        * @return The constructed model

        */

        static CBrowserCommsModel* NewL();

        /**

        * Destructor.

        */

        virtual ~CBrowserCommsModel();

	protected:  // construction

        /**

        * Constructor.

        */

		CBrowserCommsModel();

        /**

        * Second phase constructor. Leaves on failure.

        */

		void ConstructL();

    public:     // from MCommsModel

        /**

        * Get Access Point Engine object.

        * @since Series 60 1.2

        * @return Access Point Engine object

        */

        CActiveApDb& ApDb() const;

        /**

        * Get CommsDb object.

        * @since Series 60 1.2

        * @return CommsDb object

        */

        CCommsDatabase& CommsDb() const;

        /**

        * Get a copy of access points in a list.

        * The caller is responsible for destroying the returned list.

        * @since Series 60 1.2

        * @return List of access points.

        */

        CApListItemList* CopyAccessPointsL();

        /**

        * Get pointer to model's cached access points.

        * The owner of the list is the model. List contents may be updated

        * if database update occurs.

        * @since Series 60 1.2

        * @return List of access points.

        */

        const CApListItemList* AccessPointsL();

        /**

        * Refresh the cached access points.

        */

        void RefreshAccessPointsL();

        /**

        * Add an observer. Duplicates allowed.

        * @since Series 60 1.2

        * @param aObserver The observer to add.

        */

        void AddObserverL( MCommsModelObserver& aObserver );

        /**

        * Remove an observer. Does nothing if not added / already removed.

        * @since Series 60 1.2

        * @param aObserver The observer to remove.

        */

        void RemoveObserver( MCommsModelObserver& aObserver );

    public:     // from MActiveApDbObserver

        /**

        * Handle database event (refresh cached AP list on change).

        * @since Series 60 1.2

        * @param aEvent Database-related event.

        */

        void HandleApDbEventL( MActiveApDbObserver::TEvent aEvent );

    private:    // new methods

        /**

        * Get all access points (implementation detail). If database is

        * inaccessible, old data remains and update becomes pending.

        * @since Series 60 1.2

        */

        void GetAccessPointsL();

        /**

        * Get all access points (implementation detail).

        * @since Series 60 1.2

        * @param aList Append access points to this list

        */

        void DoGetAccessPointsL( CApListItemList& aList ) const;

        /**

        * Successfully got new AP data. Notify observers.

        * @since Series 60 1.2

        */

        void NotifyObserversL();

    private:    // data

        /**

        * Access Point database.

        */

        CActiveApDb* iDb;

        /**

        * Cached AP list. Since querying the AP Engine is expensive (slow),

        * we maintain a cached list of AP-s for quick access. Hopefully

        * there are not too many of them.

        */

        CApListItemList* iCachedApList;

        /**

        * Array of observer pointers. Array owned, contents not.

        */

        CArrayPtrFlat<MCommsModelObserver>* iObservers;

        /**

        * ETrue if database has changed, but could not get new data yet.

        */

        TBool iUpdatePending;

        /**

        *Etrue if referesh needs to be done on next access to cached data

        *Added as a result of performance tuning

        */

        TBool iDelayedRefresh;

	};

#endif

// End of file