org.eclipse.xwt.tools.ui.editor/src/org/eclipse/xwt/ui/editor/XWTDropTargetListener.java

/*******************************************************************************
 * Copyright (c) 2006, 2010 Soyatec (http://www.soyatec.com) 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:                                                               *  
 *     Soyatec - initial API and implementation                                * 
 *******************************************************************************/
package org.eclipse.xwt.ui.editor;

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

import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.DropTargetListener;
import org.eclipse.xwt.ui.editor.dnd.DnDAdapter;

/**
 * @author jliu jin.liu@soyatec.com
 */
public class XWTDropTargetListener implements DropTargetListener {

	private List<DnDAdapter> dndAdapters = new ArrayList<DnDAdapter>();
	private DnDAdapter acceptAdapter;

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dragOver(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragOver(DropTargetEvent event) {
		updateAcceptAdapter();
		if (acceptAdapter != null) {
			acceptAdapter.dragOver(event);
		}
	}

	/**
	 * @param event
	 */
	private void updateAcceptAdapter() {
		for (DnDAdapter dnd : dndAdapters) {
			if (dnd.isAccept()) {
				acceptAdapter = dnd;
				break;
			}
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dropAccept(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dropAccept(DropTargetEvent event) {
		if (acceptAdapter != null) {
			acceptAdapter.dropAccept(event);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#drop(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void drop(DropTargetEvent event) {
		if (acceptAdapter != null) {
			acceptAdapter.drop(event);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dragEnter(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragEnter(DropTargetEvent event) {
		updateAcceptAdapter();
		if (acceptAdapter != null) {
			acceptAdapter.dragEnter(event);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dragOperationChanged(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragOperationChanged(DropTargetEvent event) {
		updateAcceptAdapter();
		if (acceptAdapter != null) {
			acceptAdapter.dragOperationChanged(event);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dragLeave(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragLeave(DropTargetEvent event) {
		if (acceptAdapter != null) {
			acceptAdapter.dragLeave(event);
		}
	}

	public void addDnDAdapter(DnDAdapter adapter) {
		dndAdapters.add(adapter);
	}

	/**
	 * @param dndAdapters
	 *            the dndAdapters to set
	 */
	public void setDndAdapters(List<DnDAdapter> dndAdapters) {
		this.dndAdapters = dndAdapters;
	}

	/**
	 * @return the dndAdapters
	 */
	public List<DnDAdapter> getDndAdapters() {
		return dndAdapters;
	}

}