ResizeListener.java

package org.codemap.mapview;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.ControlListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;

/**
 * Used to detect when the mapview was resized and to trigger
 * the redraw/resize events.
 * When the window is dragged it delays resizing until the
 * dragging has stopped. 
 *  
 * @author deif
 */
public class ResizeListener implements ControlListener {
	
	private Composite eventsource;
	private boolean mouseDown;
	private boolean resized;
	private MapController theController;

	public ResizeListener(Composite eventsource, MapController theController) {
		this.eventsource = eventsource;
		this.theController = theController;
		setupListeners();
	}

	private void setupListeners() {
		eventsource.addControlListener(this);
		
		Display display = Display.getCurrent();
		addMouseUpListener(display);
		addMouseDownListener(display);			
	}

	private void addMouseUpListener(Display display) {
		display.addFilter(SWT.MouseDown, new Listener(){
			@Override
			public void handleEvent(Event event) {
				mouseDown();
			}
		});
	}

	private void addMouseDownListener(Display display) {
		display.addFilter(SWT.MouseUp, new Listener(){
			@Override
			public void handleEvent(Event event) {
				mouseUp();
			}
		});
	}
	
	private void mouseUp() {
		mouseDown = false;
		if (resized) {
			resized = false;
			processResize();
		}
	}	
	
	private void mouseDown() {
		mouseDown = true;
	}

	@Override
	public void controlResized(ControlEvent e) {
		if (! mouseDown) {
			processResize();
		}
		resized = true;
	}

	private void processResize() {
		theController.onResize(eventsource.getSize());
	}

	@Override
	public void controlMoved(ControlEvent e) {
		// don't care
	}


}