Drag Listener and Drop Listener

Create the following Drop and Drag listener which will be later assigned to the views.

   
package de.vogella.dnd.jface.dnd;

import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DragSourceListener;
import org.eclipse.swt.dnd.TextTransfer;

import de.vogella.dnd.jface.model.Todo;
public class MyDragListener implements DragSourceListener {

 private final TableViewer viewer;

 public MyDragListener(TableViewer viewer) {
  this.viewer = viewer;
 }

 @Override
 public void dragFinished(DragSourceEvent event) {
  System.out.println("Finshed Drag");
 }

 @Override
 public void dragSetData(DragSourceEvent event) {
  // Here you do the convertion to the type which is expected.
  IStructuredSelection selection = (IStructuredSelection) viewer
  .getSelection();
  Todo firstElement = (Todo) selection.getFirstElement();
  
  if (TextTransfer.getInstance().isSupportedType(event.dataType)) {
   event.data = firstElement.getShortDescription() + " " + firstElement.getLongDescription();
  }

 }

 @Override
 public void dragStart(DragSourceEvent event) {
  System.out.println("Start Drag");
 }

}

  

   
package de.vogella.dnd.jface.dnd;

import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerDropAdapter;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.TransferData;

import de.vogella.dnd.jface.model.ContentProviderTree;

public class MyDropListener extends ViewerDropAdapter {

 private final Viewer viewer;

 public MyDropListener(Viewer viewer) {
  super(viewer);
  this.viewer = viewer;
 }

 @Override
 public void drop(DropTargetEvent event) {
  int location = this.determineLocation(event);
  String target = (String) determineTarget(event);
  String translatedLocation ="";
  switch (location){
  case 1 :
   translatedLocation = "Dropped before the target ";
   break;
  case 2 :
   translatedLocation = "Dropped after the target ";
   break;
  case 3 :
   translatedLocation = "Dropped on the target ";
   break;
  case 4 :
   translatedLocation = "Dropped into nothing ";
   break;
  }
  System.out.println(translatedLocation);
  System.out.println("The drop was done on the element: " + target );
  super.drop(event);
 }

 // This method performs the actual drop
 // We simply add the String we receive to the model and trigger a refresh of the
 // viewer by calling its setInput method.
 @Override
 public boolean performDrop(Object data) {
  ContentProviderTree.INSTANCE.getModel().add( data.toString());
  viewer.setInput(ContentProviderTree.INSTANCE.getModel());
  return false;
 }

 @Override
 public boolean validateDrop(Object target, int operation,
   TransferData transferType) {
  return true;
  
 }

 

}