1 /*

     2 * Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:  An observer interface for the tree data model.

    15 *

    16 */

    17 

    18 

    19 #ifndef M_FSTREEOBSERVER_H

    20 #define M_FSTREEOBSERVER_H

    21 

    22 

    23 /**

    24  * MFsTreeObserver defines an interface which is used to observe tree events.

    25  * 

    26  * Observer of the tree is notified of changes in the tree structure

    27  * through this interface with appropriate events.

    28  * 

    29  * @code

    30  *

    31  * @endcode

    32  *

    33  * @lib 

    34  */

    35 NONSHARABLE_CLASS( MFsTreeObserver )

    36     {

    37 public:

    38 

    39     enum TFsTreeEvent

    40         {

    41         /** 

    42          * Item was added to the tree. 

    43          * The visible items list should be updated if needed.

    44          */

    45         EFsTreeItemAdded,

    46         

    47         /** 

    48          * Node was added to the tree. 

    49          * The visible items list should be updated if needed.

    50          */

    51         EFsTreeNodeAdded,

    52         

    53         /**

    54          * Item was removed from the tree.

    55          * The visible items list should be updated if needed.

    56          */

    57         EFsTreeItemRemoved,

    58         

    59         /**

    60          * Node was removed from the tree.

    61          * The visible items list should be updated if needed.

    62          */

    63         EFsTreeNodeRemoved,

    64         

    65         /**

    66          * All items will be removed from the tree.

    67          * The visible items list should be updated..

    68          */

    69         EFsTreeRemovedAll,

    70         

    71         /**

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

    73          * The visible items list should be updated if needed.

    74          */

    75         EFsTreeItemDataChanged,

    76         

    77         /**

    78          * Item data's visualizer has changed.

    79          * The visible items list should be updated if needed.

    80          */

    81         EFsTreeItemVisualizerChanged

    82         };

    83     

    84 public:

    85     

    86     /**

    87      * Observer of the tree is notified of changes in the tree structure

    88      * through this function.

    89      * 

    90      * @param aEvent Event which happend in the tree structure.

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

    92      */

    93     struct TFsTreeEventParams

    94         {

    95         TFsTreeEventParams(TFsTreeItemId aItemId, TFsTreeItemId aTargetNodeId, TInt aIndex ) :

    96         iItemId(aItemId), iTargetNodeId(aTargetNodeId), iIndex(aIndex) {};

    97         

    98         TFsTreeItemId iItemId;

    99         TFsTreeItemId iTargetNodeId; 

   100         TInt iIndex;

   101         };

   102     

   103     virtual void TreeEventL( const TFsTreeEvent aEvent, 

   104             const TFsTreeEventParams& aParams ) = 0;

   105     

   106     };

   107     

   108      

   109 #endif // M_FSTREEOBSERVER_H