Transfer[] types=new Transfer[]{TextTransfer.getInstance()};
//makes the ListViewer
lvActiveFields=new ListViewer(grpAnalysis,SWT.BORDER|SWT.V_SCROLL);
					lvActiveFields.setLabelProvider(new ViewerLabelProvider());
					lvActiveFields.setContentProvider(new ListContentProvider());
					lvActiveFields.setInput(fields);
					listActiveFields=lvActiveFields.getList();
					listActiveFields.setToolTipText("Drag fields of interest to this box.");
					{
						GridData gridData=new GridData(SWT.LEFT,SWT.FILL,false,true,1,1);
						gridData.widthHint=129;
						listActiveFields.setLayoutData(gridData);
					}
					{
						lvActiveFields.addDropSupport(DND.DROP_COPY,types,new DropTargetFieldsDropTargetListener(lvActiveFields));
					}

//the drop listener
//note there's some shotgun debugging code in here in a vain attempt to pin down what's going on...

private class DropTargetFieldsDropTargetListener extends ViewerDropAdapter
	{
		final TextTransfer textTransfer=TextTransfer.getInstance();

		protected DropTargetFieldsDropTargetListener(Viewer viewer)
		{
			super(viewer);
		}

		@Override
		public void dragEnter(DropTargetEvent event)
		{
			System.out.println("Drag Enter");
		}

		@Override
		public void drop(DropTargetEvent event)
		{
			System.out.println("Dropped");
			if (textTransfer.isSupportedType(event.currentDataType))
			{
				Object o=textTransfer.nativeToJava(event.currentDataType);
				String t=(String)o;
				fields.add(t);
				lvActiveFields.refresh();
			}
		}

		@Override
		public void dragOver(DropTargetEvent event)
		{
			System.out.println("Drag Over");
			
			if (textTransfer.isSupportedType(event.currentDataType))
			{
				
				Object o=textTransfer.nativeToJava(event.currentDataType);
				String t=(String)o;
				if (t!=null)
				{
					System.out.println(t);

				}
				else
				{
					System.out.println("t is null.");
				}
			}
		}

		@Override
		public void dropAccept(DropTargetEvent arg0)
		{
			System.out.println("Drop Accept");
		}

		@Override
		public void dragLeave(DropTargetEvent arg0)
		{
			System.out.println("Drag leave");
		}

		@Override
		public boolean performDrop(Object arg0)
		{
			System.out.println("Dropped");
			lvActiveFields.add(arg0);
			return true;
		}

		@Override
		public boolean validateDrop(Object arg0,int arg1,TransferData arg2)
		{
			System.out.println("Validated");
			return true;
		}
	}