/*

* Copyright (c) 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:  Event interface for group content.

*

*/

#ifndef MIMGROUPEVENT_H

#define MIMGROUPEVENT_H

#include <e32std.h>

#include <ximpbase.h>

#include <immanagementifids.hrh>

class MXIMPIdentity;

class MImGroupInfo;

class MImDataSubscriptionState;

/**

 * Event interface for group content.

 *

 * This interface is implemented by the Im and

 * event object is signalled to registered client observers

 * through MImContextObserver observer interface.

 * This event notifies clients about changes in

 * group content.

 *

 * Clients subscribe for this event with

 * MImGroups::SubscribeImGroupChangeL().

 *

 * Im signals this event when:

 * - New subscribed data is received from protocol.

 * - Data item data subscription status is updated by

 *   protocol adaptation.

 * - When client unsubscribes the data item.

 * - Im generates initial data notification

 *   to client automatically after clients subscription,

 *   when the initial data comes available from protocol.

 *

 * @ingroup imftmanagementapievents

 * 

 */

class MImGroupEvent : public MXIMPBase

    {

public:

    /** Interface ID for the MImGroupEvent. */

    enum { KInterfaceId = IM_IF_ID_GROUP_EVENT };

protected:

    /**

     * Protected destructor.

     * Object instancies can't be deleted via this interface.

     */

    virtual ~MImGroupEvent() {}

public: // Access to "delta information"

    /**

     * Gets count of new groups.

     *

     * @return The count of new groups.

     */

    virtual TInt NewGroupsCount() const = 0;

    /**

     * Gets group entry by index.

     *

     * @param [in] aIndex

     *        The index of the group entry to get.

     *

     * @return The group entry from given index.

     */

    virtual const MImGroupInfo& NewGroup(

                TInt aIndex ) const = 0;

    /**

     * Gets count of updated groups.

     *

     * @return The count of updated groups.

     */

    virtual TInt UpdatedGroupsCount() const = 0;

    /**

     * Gets group entry by index.

     *

     * @param [in] aIndex

     *        The index of the group entry to get.

     *

     * @return The group entry from given index.

     */

    virtual const MImGroupInfo& UpdatedGroup(

                TInt aIndex ) const = 0;

    /**

     * Gets count of disappeared groups.

     *

     * @return The count of disappeared groups.

     */

    virtual TInt DisappearedGroupsCount() const = 0;

    /**

     * Gets group entry by index.

     *

     * @param [in] aIndex

     *        The index of the group entry to get.

     *

     * @return The group entry from given index.

     */

    virtual const MImGroupInfo& DisappearedGroup(

                TInt aIndex ) const = 0;

public: // Access to "current information"

    /**

     * Gets count of current groups.

     *

     * Note that, current information is signalled only when

     * the client refreshes the event data from Im cache,

     * by re-issuing the data subscription.

     *

     * @return The count of current groups.

     */

    virtual TInt CurrentGroupsCount() const = 0;

    /**

     * Gets group entry by index.

     *

     * Note that, current information is signalled only when

     * the client refreshes the event data from Im cache,

     * by re-issuing the data subscription.

     *

     * @param [in] aIndex

     *        The index of the group entry to get.

     *

     * @return The group entry from given index.

     */

    virtual const MImGroupInfo& CurrentGroup(

                TInt aIndex ) const = 0;

public: // Access to subscription state

    /**

     * Returns subscription state object holding

     * information about data items data subscription state.

     *

     * @return The data items data subscription state.

     *         Object ownership is not returned.

     */

    virtual const MImDataSubscriptionState& DataSubscriptionState() const = 0;

    };

#endif // MIMGROUPEVENT_H