bundles/org.eclipse.ui.glance/src/org/eclipse/ui/glance/internal/panels/MoveTracker.java

/******************************************************************************* 
 * Copyright (c) 2017 Exyte  
 * 
 * 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: 
 *     Yuri Strot - initial API and Implementation 
 *******************************************************************************/
package org.eclipse.ui.glance.internal.panels;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;

/**
 * @author Yuri Strot
 * 
 */
public class MoveTracker implements Listener {

	public MoveTracker(Control control) {
		this.control = control;
		cursor = new Cursor(control.getDisplay(), SWT.CURSOR_SIZEALL);
		control.setCursor(cursor);
		control.addListener(SWT.MouseDown, this);
		control.addListener(SWT.Dispose, this);
	}

	public void handleEvent(Event event) {
		if (control != null && !control.isDisposed()) {
			switch (event.type) {
			case SWT.MouseDown:
				Point point = control.getDisplay().getCursorLocation();
				handleClick(point.x, point.y);
				break;
			case SWT.MouseMove:
				point = control.getDisplay().getCursorLocation();
				handleDrag(point.x - iLocation.x, point.y - iLocation.y);
				break;
			case SWT.Dispose:
				cursor.dispose();
				cursor = null;
			case SWT.MouseUp:
				control.getDisplay().removeFilter(SWT.MouseMove, this);
				control.getDisplay().removeFilter(SWT.MouseUp, this);
			}

		}
	}

	protected void handleClick(int x, int y) {
		iLocation = new Point(x, y);
		control.getDisplay().addFilter(SWT.MouseMove, this);
		control.getDisplay().addFilter(SWT.MouseUp, this);
	}

	protected void handleDrag(int dx, int dy) {
	}

	private Cursor cursor;
	private Point iLocation;
	private Control control;

}