/*
* Copyright (c) 2007, 2009, 2011, 2012 Eike Stepper (Berlin, Germany) and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Eike Stepper - initial API and implementation
*/
package org.eclipse.net4j.util.ui.dnd;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.swt.dnd.DragSourceAdapter;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.Transfer;
/**
* @author Eike Stepper
*/
public abstract class DNDDragListener<TYPE> extends DragSourceAdapter
{
private Transfer[] transfers;
private StructuredViewer viewer;
/**
* @since 3.0
*/
protected DNDDragListener(Transfer[] transfers, StructuredViewer viewer)
{
this.transfers = transfers;
this.viewer = viewer;
}
/**
* @since 3.3
*/
protected DNDDragListener(StructuredViewer viewer)
{
this.viewer = viewer;
}
/**
* @since 3.0
*/
public Transfer[] getTransfers()
{
return transfers;
}
/**
* @since 3.3
*/
public void setTransfers(Transfer[] transfers)
{
this.transfers = transfers;
}
public StructuredViewer getViewer()
{
return viewer;
}
@Override
public void dragSetData(DragSourceEvent event)
{
for (Transfer transfer : transfers)
{
if (transfer.isSupportedType(event.dataType))
{
IStructuredSelection selection = (IStructuredSelection)viewer.getSelection();
event.data = getObject(selection);
break;
}
}
}
@Override
public void dragStart(DragSourceEvent event)
{
IStructuredSelection selection = (IStructuredSelection)viewer.getSelection();
event.doit = !viewer.getSelection().isEmpty() && getObject(selection) != null;
}
protected abstract TYPE getObject(IStructuredSelection selection);
}