/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2005, 2010 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.sapphire.ui.swt.gef.dnd;

import org.eclipse.gef.EditPartViewer;
import org.eclipse.gef.Request;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.dnd.AbstractTransferDropTargetListener;
import org.eclipse.gef.requests.CreateRequest;
import org.eclipse.gef.requests.CreationFactory;
import org.eclipse.jface.util.LocalSelectionTransfer;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.dnd.DND;

/**
 * @noinstantiate This class is not intended to be instantiated by clients.
 * @noextend This class is not intended to be subclassed by clients.
 * @author <a href="mailto:shenxue.zhou@oracle.com">Shenxue Zhou</a>
 */

public class ObjectsTransferDropTargetListener extends AbstractTransferDropTargetListener {

	public ObjectsTransferDropTargetListener(EditPartViewer viewer) {
		super(viewer, LocalSelectionTransfer.getTransfer());
		setEnablementDeterminedByCommand(true);
	}

	@Override
	protected void handleDrop() {
		super.handleDrop();
		if (getCurrentEvent().detail == DND.DROP_MOVE) {
			getCurrentEvent().detail = DND.DROP_COPY;
		}
	}

	@Override
	protected void updateTargetRequest() {
		((CreateRequest) getTargetRequest()).setLocation(getDropLocation());
	}

	@Override
	protected Request createTargetRequest() {
		CreateRequest request = new CreateRequest();

		request.setFactory(new MyCreationFactory());
		request.setLocation(getDropLocation());
		return request;
	}

	@Override
	protected void handleDragOver() {

		super.handleDragOver();

		Command command = getCommand();
		if (command != null && command.canExecute())
			getCurrentEvent().detail = DND.DROP_COPY;
	}

	private static class MyCreationFactory implements CreationFactory {

		public MyCreationFactory() {
		}

		public Object getNewObject() {
			return LocalSelectionTransfer.getTransfer().getSelection();
		}

		public Object getObjectType() {
			return ISelection.class;
		}
	}
}