/*

* Copyright (c) 2004-2007 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:  An observer interface for contact views.

*

*/

#ifndef MVPBKCONTACTVIEWOBSERVER_H

#define MVPBKCONTACTVIEWOBSERVER_H

// INCLUDES

#include <e32std.h>

// FORWARD DECLARATIONS

class MVPbkContactViewBase;

class MVPbkContactLink;

// CLASS DECLARATIONS

/**

 * An observer interface for contact views.

 *

 * A client will receive events related to the view state and the view content

 * via this interface.

 * @see CVPbkContactManager::CreateContactViewLC

 */

class MVPbkContactViewObserver

    {

    public: // Interface

        /**

         * Called when a view is ready for use. 

         * 

         * This function may also be called if view is already ready. Then

         * it means that the view has been updated and the observer have

         * to take this into account.

         *

         * @param aView A contact view sending the event.

         */

        virtual void ContactViewReady(

                MVPbkContactViewBase& aView ) = 0;

        /**

         * Called when a view is unavailable for a while. 

         * 

         * When the view is again available ContactViewReady will be called.

         * The contents of the view may change completely while it is

         * unavailable.

         *

         * @param aView A contact view sending the event.

         */

        virtual void ContactViewUnavailable(

                MVPbkContactViewBase& aView ) = 0;

        /**

         * Called when a contact has been added to the view.

         *

         * @param aView A contact view sending the event.

         * @param aIndex An index of the contact in the view.

         * @param aContactLink A link to the added contact that is

         *                     valid only during the functio call.

         */

        virtual void ContactAddedToView(

                MVPbkContactViewBase& aView, 

                TInt aIndex, 

                const MVPbkContactLink& aContactLink ) = 0;

        /**

         * Called when a contact has been removed from a view.

         *

         * @param aView A contact view sending the event.

         * @param aIndex An index of the removed contact.

         * @param aContactLink A link to the removed contact that is

         *                      valid only during this function call.

         */

        virtual void ContactRemovedFromView(

                MVPbkContactViewBase& aView, 

                TInt aIndex, 

                const MVPbkContactLink& aContactLink ) = 0;

        /**

         * Called when an error occurs in the view.

         *

         * If client decides to destroy the view then it should do

         * it asynchronously because the view can access member data

         * after a call to this.

         *

         * @param aView A contact view sending the event.

         * @param aError An error code of the failure.

         * @param aErrorNotified  ETrue if the implementation has already 

         *                        notified user about the error using e.g

         *                        an ECOM plug-in, EFalse otherwise.

         */

        virtual void ContactViewError(

                MVPbkContactViewBase& aView, 

                TInt aError, 

                TBool aErrorNotified ) = 0;

        /**

         * Returns an extension point for this interface or NULL.

         *

         * @param aExtensionUid no extensions defined currently.

         * @return an extension point for this interface or NULL.

         */

        virtual TAny* ContactViewObserverExtension(TUid /*aExtensionUid*/) 

                { return NULL; }

    protected: // Destructor

        virtual ~MVPbkContactViewObserver() { }

    };

#endif  // MVPBKCONTACTVIEWOBSERVER_H

// End of File