/*****************************************************************************
 * Copyright (c) 2011 CEA LIST.
 *
 *    
 * 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:
 *  Vincent Lorenzo (CEA LIST) vincent.lorenzo@cea.fr - Initial API and implementation
 *
 *****************************************************************************/
package org.eclipse.papyrus.views.modelexplorer.dnd;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.edit.ui.dnd.LocalTransfer;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.ui.navigator.CommonDragAdapterAssistant;

/**
 * This class allows to provides Drag&Drop between the Model Explorer and the Tables (or others View/Editors)
 * 
 * 
 * 
 */
public class EObjectDragAdapterAssistant extends CommonDragAdapterAssistant {

	/**
	 * 
	 * @see org.eclipse.ui.navigator.CommonDragAdapterAssistant#getSupportedTransferTypes()
	 * 
	 * @return
	 */
	@Override
	public Transfer[] getSupportedTransferTypes() {
		return new Transfer[]{ LocalTransfer.getInstance() };
	}

	/**
	 * 
	 * @see org.eclipse.ui.navigator.CommonDragAdapterAssistant#setDragData(org.eclipse.swt.dnd.DragSourceEvent,
	 *      org.eclipse.jface.viewers.IStructuredSelection)
	 * 
	 * @param anEvent
	 * @param aSelection
	 * @return
	 */
	@Override
	public boolean setDragData(DragSourceEvent anEvent, IStructuredSelection aSelection) {
		Iterator<?> iter = aSelection.iterator();
		List<Object> selectedElements = new ArrayList<Object>();

		while(iter.hasNext()) {
			Object current = iter.next();
			if(current instanceof IAdaptable) {
				EObject eobject = (EObject)((IAdaptable)current).getAdapter(EObject.class);
				if(eobject != null) {
					selectedElements.add(eobject);
				}
			}
		}

		if(!selectedElements.isEmpty()) {
			anEvent.data = new StructuredSelection(selectedElements);
		}
		return anEvent.data != null;
	}
}