/*

* 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:  An observer interface for the tree list component.

*

*/

#ifndef M_FSTREEVISUALIZEROBSERVER_H

#define M_FSTREEVISUALIZEROBSERVER_H

#include "fstreelistconstants.h"

/**

 * MFsTreeObserver defines an interface which is used to observe tree list 

 * events.

 *

 * Observer of the tree list is notified of changes in the tree list through 

 * this interface with appropriate events.

 * @code

 *

 * @endcode

 *

 * @lib 

 */

NONSHARABLE_CLASS( MFsTreeVisualizerObserver )

    {

public:

    enum TFsTreeVisualizerEvent

        {

        // <cmail> "Base class modifications for using touch"

        /**

         * Action started for selected tree item.

         */

        EFsTreeItemTouchAction,

        /**

         * Long tap action started for selected tree item. 

         */

        EFsTreeItemTouchLongTap,

        /**

         * Touch focus for list gained. 

         */

        EFsTreeItemTouchFocused,    

        // </cmail>

        /**

         * An item received focus.

         */

        EFsTreeItemFocused,

        /**

         * Focus will be moved to the specified item/node.

         * Event triggered just before an item gets focus.

         * No action required.

         */

        EFsTreeItemWillGetFocused,

        /**

         * An item has been selected.

         */

        EFsTreeItemSelected,

        /**

         * An item with menu has been selected.

         */

        EFsTreeItemWithMenuSelected,

        /**

         * Right arrow pressed.

         */

        EFsTreeKeyRightArrow,

        /**

         * Left arrow pressed.

         */

        EFsTreeKeyLeftArrow,

        /**

         * Event generated when the list is fully hidden.

         */

        EFsTreeListVisualizerHidden,

        /**

         * Event generated when the list is fully shown.

         */

        EFsTreeListVisualizerShown,

        // <cmail>

        /**

         * Event generated when a single node is collapsed.

         */

        EFsTreeListItemCollapsed,

        /**

         * Event generated when a single node is expanded.

         */

        EFsTreeListItemExpanded,

        /**

         * Event generated when all nodes are collapsed.

         */

        EFsTreeListCollapsedAll,

        /**

         * Event generated when all nodes are expanded.

         */

        // </cmail>

        };    

public:

    /**

     * Observer of the tree list is notified of changes in the tree list

     * through this function.

     * 

     * @param aEvent Event which happend in the tree list.

     * @param aId Id of the node/item associated with the event. KFsTreeNoneID

     *            means that the event is not associated with a node/item.

     */

    // <cmail> Touch

    virtual void TreeVisualizerEventL( 

            const TFsTreeVisualizerEvent aEvent, 

            const TFsTreeItemId aId = KFsTreeNoneID ) const = 0;

    // </cmail>

    };

#endif // M_FSTREEVISUALIZEROBSERVER_H