import java.util.Vector;
import org.eclipse.jface.util.LocalSelectionTransfer;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.ListViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerDropAdapter;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSourceAdapter;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.dnd.TransferData;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class DnDTest {
  Display display = new Display();
  Shell shell = new Shell(display);

  ListViewer listViewer;

  public static class Item {
    public String name;

    public Item(String name) {
      this.name = name;
    }

    @Override
    public String toString() {
      return "Item: " + name;
    }
  }

  Vector<Item> items = new Vector<Item>();

  private void init() {
    for (int i = 0; i < 6; i++) {
      items.add(new Item("foo" + i));
    }

    listViewer = new ListViewer(shell, SWT.SINGLE);

    listViewer.setContentProvider(new IStructuredContentProvider()
      {
        public Object[] getElements(Object inputElement)
        {
          Vector v = (Vector) inputElement;
          return v.toArray();
        }

        @Override
        public void dispose()
        {
        }

        @Override
        public void inputChanged(Viewer viewer, Object oldInput, Object newInput)
        {
        }
      });

    listViewer.setInput(items);

    addDragAndDropSupport();
  }

  public void addDragAndDropSupport() {
    listViewer.addDragSupport(DND.DROP_MOVE,
        new Transfer[] { LocalSelectionTransfer.getTransfer() },
        new DragSourceAdapter()
          {
            @Override
            public void dragStart(final DragSourceEvent event)
            {
            }
          });

    listViewer.addDropSupport(DND.DROP_MOVE,
        new Transfer[] { LocalSelectionTransfer.getTransfer() },
        new ViewerDropAdapter(listViewer)
          {
            @Override
            public boolean performDrop(final Object data)
            {
              return true;
            }

            @Override
            public boolean validateDrop(Object target, int operation,
                TransferData transferType)
            {
              if (target != null)
              {
                System.out.println("target != null");
                return true;
              }
              else
              {
                System.out.println("target == null");
                return false;
              }
            }
          });
  }

  public DnDTest() {
    FillLayout layout = new FillLayout();
    shell.setLayout(layout);

    init();

    shell.setBounds(100, 100, 300, 200);
    shell.open();

    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }

    display.dispose();
  }

  public static void main(String[] args) {
    new DnDTest();
  }
}