/*

* 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:  Provides information about ongoing calls.

*

*/

#ifndef C_CALLINFORMATION_H

#define C_CALLINFORMATION_H

#include <e32base.h>

#include "mcall.h"

// forward declarations 

class MCallInformationObserver;

class CCallInformationImpl;

class CCallInfoIter;

/**

 *  Class to be used for receiving information about ongoing calls. 

 *

 *  @code

 *  // create the CCallInformation instance e.g. when the client component is created

 *  iCallInfo = CCallInformation::NewL(); 

 *  iCallInfo->NotifyCallInformationChanges(*iObserver);

 *  

 *  // and use it when needed. 

 *  CCallInfoIter& iter = iCallInfo->GetCallsL();

 *  @endcode

 *

 *  @lib telephonyservice.lib

 *  @since S60 v5.1 

 */

NONSHARABLE_CLASS( CCallInformation ) : public CBase

    {

public:

    /**

     * Two-phased constructor.          

     */

    IMPORT_C static CCallInformation* NewL();

    /**

    * Destructor.

    */

    virtual ~CCallInformation();

    /**

     * Allows a client to be notified when there are changes in current calls.

     * There can be only one observer per CCallInformation instance.

     *

     * @since S60 v5.1 

     * @param aObserver Observer for notifications.

     */

     IMPORT_C void NotifyCallInformationChanges( MCallInformationObserver& aObserver );

    /**

     * Used to cancel previously placed NotifyCallInformationChanges call.

     *

     * @since S60 v5.1      

     */

     IMPORT_C void CancelNotification();

    /**

     * Gets the snapshot of ongoing calls. 

     * The returned reference should not be stored as member variable 

     * as it goes out of scope when there are changes in call information.

     *

     * @since S60 v5.1      

     * @return Ongoing calls.

     */

     IMPORT_C CCallInfoIter& GetCallsL( );

    /**

     * Returns information whether call in given state exist.

     * 

     * @since S60 v5.2

     * @param aState Specifies a call state that is used as a search key.

     * @return ETrue if call in given state exist.

     */

    IMPORT_C TBool IsCallInState( CCPCall::TCallState aState ) const;

private:

    CCallInformation();

    void ConstructL();

private: // data    

    };

#endif // C_CALLINFORMATION_H