/*

* Copyright (c) 2006-2007 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:  Registry observer is listening to registry changes and

* 				  and reporting the changed devices to the listener.

*

*/

#ifndef BTREGISTRYOBSERVER_H

#define BTREGISTRYOBSERVER_H

#include <e32base.h>

#include <e32property.h>

#include <btmanclient.h>

#include <btengdevman.h> 

/** This class will inform the listener about the new BTregistry status

*after registry change events. 

*

* This class will listen to events about registry changes and inform

* the listener about the latest registry status. The listener can

* also ask the status using refresh. This is usefull for for

* for example retrieval of initial lists of devices. 

*

*@lib btdevmodel.dll

*@since S60 V3.2

*/

NONSHARABLE_CLASS(MBTRegistryObserver)

    {

public:

	/** The aDeviceArray constents are deleted after this

	* call returns. If storage is wanted the array and its contents

	* must be copied by implementor.

	*/

    virtual void RegistryChangedL(const CBTDeviceArray* aDeviceArray) = 0;

    };

NONSHARABLE_CLASS(CBTRegistryObserver) : public CActive, public MBTEngDevManObserver

    {

public: 

	/** NewL

	 *@param aObserver The class that is listening to registry changes

	 *@param aPattern The pattern to be used to retrieve the changed objects.

	 */

    static CBTRegistryObserver* NewL(MBTRegistryObserver* aObserver, 

        const TBTRegistrySearch aPattern);

    /** Destructor*/

    virtual ~CBTRegistryObserver();       

	/** Start listening to registry changes. 

	 *

	 *Calling this while registry observer is running is silently ignored.

	 */

    void StartIfNotRunning();

    /* Registry observer will retrieve list of devices in the backround 

     * and send it to the listener, when one is retrieved.

     */

    void Refresh();

    /** Check if this is running.       

     *@return ETrue if not listening to registry changes.

     */

    inline TBool IsStopped() {return iIsStopped;}

    /** This will stop listening and cancel any retrieval of devicelists,

    * if any.

    * @param none.

    * @return none.

    */

    void Cancel();    

private:

	/* Constructor that may not leave.

	 *@param aObserver The class that is listening to registry changes

	 *@param aPattern The pattern to be used to retrieve the changed objects.

	 */

    CBTRegistryObserver(MBTRegistryObserver* aObserver, const TBTRegistrySearch aPattern);

	/** 2nd phase constructor. Called by NewL only.

    * @param none.

    * @return none.	

	 */

    void ConstructL();

	/** This is called when registry changes occur, but not when deviceLists are

	* retrieved, since HandleGetDevicesComplete is called then. 

	*

	* If one or more registry events occur during devicelist retrieval, there

	* will be one new devicelist retrieval after the current retrieval is done.

	*

    * @param none.

    * @return none.

	*/

    void RunL();

    /** This will clear iRegDeviceArray and delete its contents.

    * @param none.

    * @return none.     

    */

    void DeleteAllocatedDevices();

    /** This will cancel listening. To be called by Cancel only.

     * @param none.

     * @return none.

	 */

    void DoCancel();    

	/** This is called when devicelist have been read from BtDevMan 

	* @param aErr KErrNone or the accurred error.

	* @param aDeviceArray the devices that have been retrieved.

    * @return none.

    */

    void HandleGetDevicesComplete(TInt aErr, CBTDeviceArray* aDeviceArray);

private:

    MBTRegistryObserver* iObserver; // the class listening to this class

    CBTDeviceArray* iRegDeviceArray;  // this is used for retrieving devices

    TBTRegistrySearch iSearchPattern; // the search used to retrieve devices

    								 // NOTE: this class does not filter the results,

    								 // but the one listening to this (if filtering is done).

    RProperty iProperty;

    CBTEngDevMan* iDevMan;			// the object that is used to retrieve the device lists.

    TBool iIsStopped;				// is this runining.

    TBool iAnotherEventPending;		// Has there been one or more changes during this retrieval.

    								// if this is true then HandleGetDevices will start a new search.

    };

#endif