/*

* 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_FSTREELISTOBSERVER_H

#define M_FSTREELISTOBSERVER_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( MFsTreeListObserver )

    {

public:

    enum TFsTreeListEvent

        {

        /** 

         * An item was added to the tree list. 

         * No action required.

         */

        EFsTreeListItemAdded,

        /** 

         * A node was added to the tree list. 

         * No action required.

         */

        EFsTreeListNodeAdded,

        /** 

         * An item was removed from the tree list. 

         * No action required.

         */

        EFsTreeListItemRemoved,

        /** 

         * A node was removed from the tree list.

         * No action required.

         */

        EFsTreeListNodeRemoved,

        /**

         * All items and nodes were removed from the tree list.

         * No action required.

         */

        EFsTreeListRemovedAll,

        /**

         * Item/Node was moved from one parent to the other in the tree list.

         * No action required.

         */

        EFsTreeListItemMoved,

        /**

         * Item's/Node's data has changed.

         * No action required.

         */

        EFsTreeListItemDataChanged,

        /**

         * Item data's visualizer has changed.

         * No action required.

         */

        EFsTreeListItemVisualizerChanged,

        /**

         * Node data's visualizer has changed.

         * No action required.

         */

        EFsTreeListNodeVisualizerChanged,

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

        /**

         * Action started for selected tree item.

         */

        EFsTreeListItemTouchAction,

        /**

         * Long tap action started for selected tree item. 

         */

        EFsTreeListItemTouchLongTap,

        /**

         * Touch focus for list gained. 

         */

        EFsTreeListItemTouchFocused,    

        // </cmail>

        /**

         * Item/Node was selected in the tree list. It means that the user

         * pressed a selection (or other, depending on the implementation of

         * the tree list) key on item/node.

         * 

         * No action required.

         */

        EFsTreeListItemSelected,

        /**

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

         * Event triggered just before an item gets focus.

         * No action required.

         */

        EFsTreeListItemWillGetFocused,

        /**

         * Focus was moved to the specified item/node.

         * No action required.

         */

        EFsTreeListItemFocused,

        /**

         * Item/node was marked.

         * No action required.

         */

        EFsTreeListItemMarked,

        /**

         * Item/node was unmarked.

         * No action required.

         */

        EFsTreeListItemUnmarked,

        /**

         * Item/node was dimmed.

         * No action required.

         */

        EFsTreeListItemDimmed,

        /**

         * Loop event. Focus has moved from the last item item in the list to 

         * the first or form the first to the last.

         * 

         * No action required.

         */

        EFsTreeListLoop,

        /**

         * List became visible.

         * No action required.

         */

        EFsTreeListShown,

        /**

         * List has been hidden.

         * No action required.

         */

        EFsTreeListHidden,

        /**

         * Text size in all the items/nodes in the list has increased.

         * No action required.

         */

        EFsTreeListTextSizeIncreased,

        /**

         * Text size in all the items/nodes in the list has decreased.

         * No action required.

         */

        EFsTreeListTextSizeDecreased,

        /**

         * Node change state to unrolled.

         * No action required.

         */

        EFsTreeListNodeUnrolled,

        /**

         * Node change state to rolled.

         * No action required.

         */

        EFsTreeListNodeRolled,

        /**

         * List received focus

         */

        EFsTreeListFocusReceived,

        /**

         * List lost focus

         */          

        EFsTreeListFocusLost,

        /**

         * Item has been selected

         */

        EFsTreeItemSelected,

        /**

         * Item with menu has been selected

         */ 

        EFsTreeItemWithMenuSelected,

        /**

         * Right click on list.

         */

        EFsTreeListKeyRightArrow,

        /**

         * Left click on list.

         */

        EFsTreeListKeyLeftArrow,

        // <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 TreeListEventL( const TFsTreeListEvent aEvent, 

                                const TFsTreeItemId aId = KFsTreeNoneID ) = 0;

    // </cmail>

    };

#endif // M_FSTREELISTOBSERVER_H