Application: gvSIG desktop

package org.gvsig.gui.beans.controls.dnd;

import java.awt.datatransfer.DataFlavor;

import java.awt.datatransfer.StringSelection;

import java.awt.datatransfer.Transferable;

import java.awt.datatransfer.UnsupportedFlavorException;

import java.awt.dnd.DnDConstants;

import java.awt.dnd.DragGestureEvent;

import java.awt.dnd.DragGestureListener;

import java.awt.dnd.DragSource;

import java.awt.dnd.DragSourceDragEvent;

import java.awt.dnd.DragSourceDropEvent;

import java.awt.dnd.DragSourceEvent;

import java.awt.dnd.DragSourceListener;

import java.awt.dnd.DropTarget;

import java.awt.dnd.DropTargetDragEvent;

import java.awt.dnd.DropTargetDropEvent;

import java.awt.dnd.DropTargetEvent;

import java.awt.dnd.DropTargetListener;

import java.io.IOException;

import java.util.ArrayList;

import java.util.StringTokenizer;

import javax.swing.JList;

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2005 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

 *

 * $Id$

 * $Log$

 * Revision 1.1  2006-03-22 11:18:29  jaume

 * *** empty log message ***

 *

 * Revision 1.4  2006/02/28 15:25:14  jaume

 * *** empty log message ***

 *

 * Revision 1.2.2.3  2006/01/31 16:25:24  jaume

 * correcciones de bugs

 *

 * Revision 1.3  2006/01/26 16:07:14  jaume

 * *** empty log message ***

 *

 * Revision 1.2.2.1  2006/01/26 12:59:33  jaume

 * 0.5

 *

 * Revision 1.2  2006/01/24 14:36:33  jaume

 * This is the new version

 *

 * Revision 1.1.2.1  2006/01/10 13:11:38  jaume

 * *** empty log message ***

 *

 * Revision 1.1.2.1  2005/12/29 08:26:54  jaume

 * some gui issues where fixed

 *

 * Revision 1.1.2.1  2005/12/19 18:12:35  jaume

 * *** empty log message ***

 *

 *

 */

/**

 * <p>

 * A JList that allows drag'n'drop elements. It accepts changing position of

 * one or more elements within the list, adding other from other JDnDList's,

 * removing sets of selected items, and other features.

 * </p>

 * <p>

 * In order to use this features you have to use a JDnDListModel as the list's

 * model.

 * </p>

 * jaume dominguez faus - jaume.dominguez@iver.es

 */

public class JDnDList extends JList implements DragSourceListener, DragGestureListener, DropTargetListener{

    private DragSource dragSource;

    private DropTarget dropTarget;

    private boolean    dragging;

    private int overIndex;

    private int[] selectedIndices;

    public JDnDList() {

        dropTarget = new DropTarget (this, this);

        dragSource = new DragSource();

        dragSource.createDefaultDragGestureRecognizer( this, DnDConstants.ACTION_MOVE, this);

      }

    public JDnDList( JDnDListModel model ) {

        super( model );

        // Configure ourselves to be a drag source

        dragSource = new DragSource();

        dragSource.createDefaultDragGestureRecognizer( this, DnDConstants.ACTION_MOVE, this);

        // Configure ourselves to be a drop target

        dropTarget = new DropTarget( this, this );

    }

    public void dragGestureRecognized(DragGestureEvent dge)  {

        this.selectedIndices = this.getSelectedIndices();

        Object[] selectedObjects = this.getSelectedValues();

        if( selectedObjects.length > 0 ) {

            StringBuffer sb = new StringBuffer();

            for( int i=0; i<selectedObjects.length; i++ ) {

                sb.append( selectedObjects[ i ].toString() + "\n" );

            }

            // Build a StringSelection object that the Drag Source

            // can use to transport a string to the Drop Target

            StringSelection text = new StringSelection( sb.toString() );

            // Start dragging the object

            this.dragging = true;

            dragSource.startDrag( dge, DragSource.DefaultMoveDrop, text, this );

        }

    }

    public void dragDropEnd(DragSourceDropEvent dsde) {

        this.dragging = false;

    }

    public void dragExit(DropTargetEvent dte) {

        this.overIndex = -1;

    }

    public void dragEnter(DropTargetDragEvent dtde) {

        this.overIndex = this.locationToIndex( dtde.getLocation() );

        this.setSelectedIndex( this.overIndex );

    }

    public void dragOver(DropTargetDragEvent dtde) {

        // See who we are over...

        int overIndex = this.locationToIndex( dtde.getLocation() );

        if( overIndex != -1 && overIndex != this.overIndex ) {

            // If the value has changed from what we were previously over

            // then change the selected object to the one we are over; this

            // is a visual representation that this is where the drop will occur

            this.overIndex = overIndex;

            this.setSelectedIndex( this.overIndex );

        }

    }

    public void drop(DropTargetDropEvent dtde) {

        try {

            Transferable transferable = dtde.getTransferable();

            if( transferable.isDataFlavorSupported( DataFlavor.stringFlavor ) ) {

                dtde.acceptDrop( DnDConstants.ACTION_MOVE );

                // Find out where the item was dropped

                int newIndex = this.locationToIndex( dtde.getLocation() );

                // Get the items out of the transferable object and build an

                // array out of them...

                String s = ( String )transferable.getTransferData( DataFlavor.stringFlavor );

                StringTokenizer st = new StringTokenizer( s );

                ArrayList items = new ArrayList();

                while( st.hasMoreTokens() ) {

                    items.add( st.nextToken() );

                }

                JDnDListModel model = ( JDnDListModel )this.getModel();

                // If we are dragging from our this to our list them move the items,

                // otherwise just add them...

                if( this.dragging ) {

                    //model.itemsMoved( newIndex, items );

                    model.itemsMoved( newIndex, this.selectedIndices );

                } else {

                    model.insertItems( newIndex, items );

                }

                // Update the selected indicies

                int[] newIndicies = new int[ items.size() ];

                for( int i=0; i<items.size(); i++ ) {

                    newIndicies[ i ] = newIndex + i;

                }

                this.setSelectedIndices( newIndicies );

                // Reset the over index

                this.overIndex = -1;

                dtde.getDropTargetContext().dropComplete( true );

            } else {

                dtde.rejectDrop();

            }

        } catch( IOException exception ) {

            exception.printStackTrace();

            System.err.println( "Exception" + exception.getMessage());

            dtde.rejectDrop();

        } catch( UnsupportedFlavorException ufException ) {

            ufException.printStackTrace();

            System.err.println( "Exception" + ufException.getMessage());

            dtde.rejectDrop();

        }

    }

    /* (non-Javadoc)

     * @see java.awt.dnd.DragSourceListener#dragEnter(java.awt.dnd.DragSourceDragEvent)

     */

    public void dragEnter(DragSourceDragEvent dsde) {

    }

    /* (non-Javadoc)

     * @see java.awt.dnd.DragSourceListener#dragOver(java.awt.dnd.DragSourceDragEvent)

     */

    public void dragOver(DragSourceDragEvent dsde) {

    }

    /* (non-Javadoc)

     * @see java.awt.dnd.DragSourceListener#dropActionChanged(java.awt.dnd.DragSourceDragEvent)

     */

    public void dropActionChanged(DragSourceDragEvent dsde) {

    }

    /* (non-Javadoc)

     * @see java.awt.dnd.DragSourceListener#dragExit(java.awt.dnd.DragSourceEvent)

     */

    public void dragExit(DragSourceEvent dse) {

    }

    /* (non-Javadoc)

     * @see java.awt.dnd.DropTargetListener#dropActionChanged(java.awt.dnd.DropTargetDragEvent)

     */

    public void dropActionChanged(DropTargetDragEvent dtde) {

    }

}