/*
* DraggableList.java
*
* Created on March 1, 2006, 1:47 PM
*/
package ika.gui;
import ika.gui.*;
import java.beans.*;
import java.io.Serializable;
import java.awt.dnd.*;
import javax.swing.*;
import java.awt.datatransfer.*;
import java.util.*;
import java.io.*;
/**
* A JList that allows the list items to be re-ordered by drag and drop.
* Based on https://www.informit.com/guides/content.asp?g=java&seqNum=58
* With extensions to support not only Strings as list objects, but any class.
* Only dragging within the same list is supported.
* @author Bernhard Jenny, Institute of Cartography, ETH Zurich
*/
public class DraggableList extends JList implements DragSourceListener,
DragGestureListener,
DropTargetListener, Serializable {
/*
public static void main(String [] ars) {
JFrame frame = new JFrame();
Object[] v = new Object[]{"pipo", "gaga", "toto", "ginio"};
DraggableList dndList = new DraggableList(v);
frame.getContentPane().add(dndList);
frame.pack();
frame.show();
}
*/
private DragSource dragSource;
private DropTarget dropTarget;
/** set flag while we are dragging
*/
private boolean dragging = false;
/** List index of the item that we are currently dragging over
**/
private int overIndex = -1;
/** Remember the selected list items while dragging.
*/
private int[] selectedIndicies;
/** Name of the property changed event that is sent after the model
* has changed due to a dragging operation.*/
public static final String MODEL_PROPERTY = "modelProperty";
public DraggableList( DnDListModel model ) {
super( model );
this.init();
}
public DraggableList(DefaultListModel defaultListModel) {
super (new DnDListModel(defaultListModel));
this.init();
}
public DraggableList(Object[] listData){
super (new DnDListModel(listData));
this.init();
}
public DraggableList(Vector listData) {
super (new DnDListModel(listData));
this.init();
}
public DraggableList() {
super(new DnDListModel());
this.init();
}
// make sure the DnDListModel is not replaced by another type of ListModel
public void setModel(ListModel model) {
if (model instanceof DnDListModel == false)
model = new DnDListModel(model);
super.setModel(model);
}
// make sure the DnDListModel is not replaced by another type of ListModel
public void setListData(Object[] listData) {
this.setModel(new DnDListModel(listData));
}
// make sure the DnDListModel is not replaced by another type of ListModel
public void setListData(Vector listData) {
this.setModel(new DnDListModel(listData));
}
private void init() {
// 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.selectedIndicies = this.getSelectedIndices();
Object[] selectedObjects = this.getSelectedValues();
if( selectedObjects.length > 0 ) {
/* Original code
StringBuffer sb = new StringBuffer();
for( int i=0; i<selectedObjects.length; i++ ) {
sb.append( selectedObjects[ i ].toString() + System.getProperty("line.separator") );
}
// 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 );
*/
// Start dragging the object
this.dragging = true;
this.dragSource.startDrag( dge, DragSource.DefaultMoveDrop,
new ObjTransfer(Arrays.asList(selectedObjects)), 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 {
/* Original code
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() );
}
DnDListModel model = ( DnDListModel )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.selectedIndicies );
} 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();
}
**/
// only drag from this DraggableList accepted
if (!this.dragging) {
dtde.rejectDrop();
return;
}
DataFlavor dataFlavor = getDefaultTransferDataFlavor();
Transferable transferable = dtde.getTransferable();
if( transferable.isDataFlavorSupported(dataFlavor) ) {
dtde.acceptDrop( DnDConstants.ACTION_MOVE );
// Find out where the item was dropped
int newIndex = this.locationToIndex( dtde.getLocation() );
// move the items in the list
DnDListModel model = ( DnDListModel )this.getModel();
model.itemsMoved( newIndex, this.selectedIndicies );
// Update the selected indicies
List list = (List)transferable.getTransferData(dataFlavor);
int[] newIndicies = new int[ list.size() ];
for( int i=0; i<list.size(); i++ ) {
newIndicies[ i ] = newIndex + i;
}
this.setSelectedIndices( newIndicies );
// Reset the over index
this.overIndex = -1;
dtde.getDropTargetContext().dropComplete( true );
this.firePropertyChange(MODEL_PROPERTY, null, model);
} 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();
}
}
public void dragEnter(DragSourceDragEvent dsde) {
}
public void dragOver(DragSourceDragEvent dsde) {
}
public void dropActionChanged(DragSourceDragEvent dsde) {
}
public void dragExit(DragSourceEvent dse) {
}
public void dropActionChanged(DropTargetDragEvent dtde) {
}
private static DataFlavor getDefaultTransferDataFlavor() {
return new DataFlavor(java.lang.Object.class, "Generic object");
}
private class ObjTransfer implements Transferable {
Object data;
public ObjTransfer(java.lang.Object data) {
this.data = data;
}
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[]{getDefaultTransferDataFlavor()};
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return java.lang.Object.class.equals(flavor.getRepresentationClass());
}
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
return data;
}
}
}