CursorUtils.java

/*******************************************************************************
 * Copyright (c) 2014, 2015 itemis AG 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:
 *     Alexander Nyßen (itemis AG)  - initial API and implementation
 *     Matthias Wienand (itemis AG) - initial API and implementation
 *
 *******************************************************************************/
package org.eclipse.gef.fx.utils;

import java.awt.MouseInfo;
import java.awt.PointerInfo;

import org.eclipse.gef.geometry.planar.Point;

/**
 * The {@link CursorUtils} class contains utility methods for determining the
 * current pointer location ({@link #getPointerLocation()}).
 *
 * @author anyssen
 * @author mwienand
 *
 */
public class CursorUtils {

	private static final String JAVA_AWT_HEADLESS_PROPERTY = "java.awt.headless";

	/**
	 * Returns the current pointer location.
	 *
	 * @return The current pointer location.
	 */
	public static Point getPointerLocation() {
		// XXX: Ensure AWT is not considered to be in headless mode, as
		// otherwise MouseInfo#getPointerInfo() will not work; therefore
		// adjust AWT headless property, if required
		String awtHeadlessPropertyValue = System
				.getProperty(JAVA_AWT_HEADLESS_PROPERTY);
		if (awtHeadlessPropertyValue != null
				&& awtHeadlessPropertyValue != Boolean.FALSE.toString()) {
			System.setProperty(JAVA_AWT_HEADLESS_PROPERTY,
					Boolean.FALSE.toString());
		}
		// retrieve mouse location
		PointerInfo pi = MouseInfo.getPointerInfo();
		java.awt.Point mp = pi.getLocation();

		// restore AWT headless property
		if (awtHeadlessPropertyValue != null) {
			System.setProperty(JAVA_AWT_HEADLESS_PROPERTY,
					awtHeadlessPropertyValue);
		}
		return new Point(mp.x, mp.y);
	}
}