Drag'n drop : reacting/animating on drag, according to mouse pos in target

Question

Hi fellow Java coders,
I'm using drag'n drop support for some JPanel I'm using in order to make them able to change their layout in their parent or to stack themselves in a tab panel.
The drag n drop itself works fine (I took the example provided in do, the one with drag'n'dropped children pics).
But I would like to be able to react according to mouse position in the target panel, the one that receives the drop. I would like to change mouse cursor according to where is the mouse position inside the target panel, or animating / repainting things inside this target panel.
The lock I have is that with drag'n drop, MouseListener is not called at all when in drag movement, so I can't handle mouse events.
Is there a way to handle this case, when you wan't to react when dragging data above a possible target component, before having dropped it ?
Thank you in advance,
Alexis.

Answer 1

This grew larger than I planned, but here is an example that show different cursors for different components.
Drag from the center and the cursor will change for each of the border labels.
The code I origionally used this in uses custom cursors Crated by System.createCustomCursor.
This is not really pretty, but it works.
import java.awt.*;
import java.awt.dnd.*;
import javax.swing.*;
import java.awt.dnd.peer.*;
import java.awt.datatransfer.*;
public class DnDFeedBack extends JFrame
    public DnDFeedBack()
        super( "DnD Feed Back Example");
        setDefaultCloseOperation( EXIT_ON_CLOSE );
        JPanel panel = new JPanel( new BorderLayout() );
        JLabel comp = new JLabel( "North Drop" );
        comp.setBorder( BorderFactory.createLineBorder( Color.black ) );
        new DTFeedBackListener( comp, Cursor.getPredefinedCursor( Cursor.HAND_CURSOR ) );
        panel.add( comp, BorderLayout.NORTH );
        comp = new JLabel( "East Drop" );
        comp.setBorder( BorderFactory.createLineBorder( Color.black ) );
        new DTFeedBackListener( comp, Cursor.getPredefinedCursor( Cursor.CROSSHAIR_CURSOR ));
        panel.add( comp, BorderLayout.EAST );
        comp = new JLabel( "West Drop" );
        comp.setBorder( BorderFactory.createLineBorder( Color.black ) );
        new DTFeedBackListener( comp, Cursor.getPredefinedCursor( Cursor.TEXT_CURSOR ));
        panel.add( comp, BorderLayout.WEST );
        comp = new JLabel( "South Drop" );
        comp.setBorder( BorderFactory.createLineBorder( Color.black ) );
        new DTFeedBackListener( comp, Cursor.getPredefinedCursor( Cursor.WAIT_CURSOR ));
        panel.add( comp, BorderLayout.SOUTH );
        comp = new JLabel( "Drag Source" );
        comp.setBorder( BorderFactory.createLineBorder( Color.black ) );
        new FeedBackDS( comp );
        panel.add( comp, BorderLayout.CENTER );
        setContentPane( panel );
        pack();
        setLocationRelativeTo( null );
        setVisible( true );
    public static void main( String[] args )
        new DnDFeedBack();
    public class FeedBackDS extends DragSourceAdapter implements DragGestureListener
        public FeedBackDS( JComponent comp )
            new MYDragSource().createDefaultDragGestureRecognizer(
                                                                 comp, // component where drag originates
                                                                 DnDConstants.ACTION_COPY_OR_MOVE, // actions
                                                                 this); // drag gesture listener
        public void dragGestureRecognized(DragGestureEvent dge)
            dge.startDrag( DragSource.DefaultMoveNoDrop,
                           new java.awt.datatransfer.StringSelection( "FAKE DATA") );
    public class DTFeedBackListener extends DropTargetAdapter
        JComponent comp;
        Cursor cursor;
        public DTFeedBackListener( JComponent comp, Cursor cursor )
            DropTarget dt = new DropTarget( comp, this );
            dt.setDefaultActions(DnDConstants.ACTION_COPY_OR_MOVE);
            this.comp = comp;
            this.cursor = cursor;
        public void dragExit(DropTargetEvent dte)
            setFeedBackCursor(DragSource.DefaultMoveNoDrop);
        public void dragEnter(DropTargetDragEvent dtde)
            dtde.acceptDrag( DnDConstants.ACTION_COPY_OR_MOVE );
            setFeedBackCursor(cursor);
        public void drop(DropTargetDropEvent dtde){}
    public class MYDragSource extends DragSource
        public MYDragSource()
            super();
        protected DragSourceContext createDragSourceContext(DragSourceContextPeer dscp, DragGestureEvent dgl, Cursor dragCursor, Image dragImage, Point imageOffset, Transferable t, DragSourceListener dsl)
            return new MYDragSourceContext(dscp, dgl, dragCursor, dragImage, imageOffset, t, dsl);
    private static Cursor fbCursor;
    public class MYDragSourceContext extends DragSourceContext
        private transient DragSourceContextPeer peer;
        private Cursor              cursor;
        public MYDragSourceContext(DragSourceContextPeer dscp, DragGestureEvent dgl, Cursor dragCursor, Image dragImage, Point imageOffset, Transferable t, DragSourceListener dsl)
            super( dscp, dgl, dragCursor, dragImage, imageOffset, t, dsl);
            peer         = dscp;
            cursor       = dragCursor;
        protected synchronized void updateCurrentCursor(int dropOp, int targetAct, int status)
            setCursorImpl(fbCursor);
        private void setCursorImpl(Cursor c)
            if( cursor == null || !cursor.equals(c) )
                cursor = c;
                if( peer != null ) peer.setCursor(cursor);
    public static void setFeedBackCursor( Cursor cursor )
        fbCursor = cursor;
}