/*

* 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:  An interface for text based contact view filtering.

*

*/

#ifndef M_MVPBKCONTACTVIEWFILTERING_H

#define M_MVPBKCONTACTVIEWFILTERING_H

#include <e32def.h>

#include <bamdesca.h>

// FORWARDS DECLARATIONS

class MVPbkContactViewBase;

class MVPbkContactViewObserver;

class MVPbkContactBookmarkCollection;

/**

 * An interface for text based contact view filtering.

 *

 * Contact views can support filtering based on search string and

 * always included contacts by implementing this interface.

 *

 * A view stack usage:

 *

 * The client can create a stack structure of filtered views. E.g

 *

 * 1) Client creates a filtered view using find text "J"

 * 2) It then waits that the new view becomes ready.

 * 3) Then it uses the new view to create next level view for "Jo".

 * 4) The client waits that the new view becomes ready.

 * 5) The client again uses the new view for creating third level view "Joe"

 * 6) After the third filtered view becomes ready the client has 4 views:

 *    The base view that includes all the contacts and 3 filtered views

 *    for texts "J", "Jo" and "Joe". It's up to store implementation

 *    to optimize the used resources in case the store supports thousands

 *    of contacts.

 *

 * If client uses always included contacts then they must be same for all

 * views in a stack.

 *

 * View events must come in order: bottom view first.

 */

class MVPbkContactViewFiltering

    {

public:

    /**

     * Creates a new filtered view asynchronously.

     * 

     * The parent view will be filtered according to given criteria and

     * then the client will be notified via MVPbkContactViewObserver.

     * The parent view must be ready before creating a new filtered view,

     * The created view must be destroyed before the parent view and

     * not vice versa.

     *

     * @param aObserver The observer that will be notified when the view

     *                  is ready. Client shouldn't use the view before

     *                  it has been notified.

     * @param aFindWords An array of words that must match to the contact.

     * @param aAlwaysIncluded Contacts that must be in the view

     *                        even they don't match to aFindWords.

     *                        This an optional parameter. Give

     *                        NULL if not needed. Client must keep

     *                        the instance alive while the view exists.

     * @return a filtered view that must also support view filtering.

     */

    virtual MVPbkContactViewBase* CreateFilteredViewLC( 

            MVPbkContactViewObserver& aObserver,

            const MDesCArray& aFindWords,

            const MVPbkContactBookmarkCollection* aAlwaysIncluded ) = 0;

    /**

     * Updates an existing filtered view asynchronously. 

     * 

     * This must be implemented by the views that were previously

     * created by CreateFilteredViewLC. Otherwise leaves with KErrNotSupported.

     *

     * @param aFindWords an array of words that must match to the contact.

     * @param aAlwaysIncluded Contacts that must be in the view

     *                        even they don't match to aFindWords.

     *                        This an optional parameter. Give

     *                        NULL if not needed. Client must keep

     *                        the instance alive while the view exists.

     * @exception KErrNotSupported if the view itself is not a filtered view.

     */

    virtual void UpdateFilterL( 

            const MDesCArray& aFindWords,

            const MVPbkContactBookmarkCollection* aAlwaysIncluded ) = 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* ContactViewFilteringExtension(TUid /*aExtensionUid*/) 

        { return NULL; }

protected:

    /**

     * Virtual Phonebook client doesn't own this instance.

     */

	~MVPbkContactViewFiltering() {}

    };

#endif // M_MVPBKCONTACTVIEWFILTERING_H