[news.eclipse.platform.swt] Re: How would I implement zoom-in-region for

[adam.preble@xxxxxxxxx (Adam Preble)]

Grant,

Thanks for the reference to Tracker.  I have been dabbling with it on and 
off the past few days.  I took the snippet that draws a fix-sized box and 
started to hack at it.  I figured out the SWT.RESIZE style is the one I 
want for my redrawable rectangle.  

There's one problem; I can't seem to get MouseUp events to work.  I got 
the initial MouseDown event to work since it creates the tracker, but I 
want a MouseUp event to know when user is finished drawing the tracker.  
I've tried a generic listener with SWT.MouseUp, as well as a MouseListener 
with MouseUp() overridden.  Neither seems to work.

This might be a more generic problem that warrants its own thread, but I 
thought I'd tack it on to this discussion first.  Here is my source code.

package practice;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.ControlListener;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tracker;

public class TrackerMouseDown {

	private static int firstX = -1;
	private static int firstY = -1;
	private static Display display;
	private static Shell shell;

	private static ControlListener trackerListener = new ControlListener() {
		public void controlMoved(ControlEvent e) {
			System.out.println("Moved");
		}
		
		public void controlResized(ControlEvent e) {
			System.out.println("Resized");			
		}
	};

	/* Experiment with a MouseListener
	private static MouseListener mouseListener = new MouseListener() { 
		public void mouseDown(MouseEvent e) {
			System.out.println("Mouse is down");
			firstX = e.x;
			firstY = e.y;

			// Use the RESIZE style to insist on drawing a resizeable rectangle
			Tracker tracker = new Tracker(shell, SWT.RESIZE);
			tracker.addControlListener(trackerListener);
			tracker.setRectangles(new Rectangle[] { new Rectangle(firstX, firstY, 
e.x - firstX, e.y - firstY), });
			tracker.open();
		}

		public void mouseUp(MouseEvent e) {						
			System.out.println("Mouse is up");
		}

		public void mouseDoubleClick(MouseEvent arg0) {
			// TODO Auto-generated method stub
			
		}
	};
	*/
	
	private static Listener listener = new Listener() { 
		public void handleEvent(Event e) {
			switch(e.type) {
			case SWT.MouseDown:
				System.out.println("Mouse is down");
				firstX = e.x;
				firstY = e.y;

				// Use the RESIZE style to insist on drawing a resizeable rectangle
				Tracker tracker = new Tracker(shell, SWT.RESIZE);
				tracker.addControlListener(trackerListener);
				tracker.setRectangles(new Rectangle[] { new Rectangle(firstX, firstY, 
e.x - firstX, e.y - firstY), });
				tracker.open();
				break;
			case SWT.MouseUp:
				System.out.println("Mouse is up");
				break;
			
			case SWT.MouseMove:
				// Do nothing for now
				break;
				
			}	
		}
	};

	public static void main(String[] args) {

		display = new Display();
		shell = new Shell(display);

		shell.open();
		shell.addListener(SWT.MouseDown, listener);
		shell.addListener(SWT.MouseUp, listener);
		shell.addListener(SWT.MouseMove, listener);

		/*  MouseListener
		shell.addMouseListener(mouseListener);
		*/
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch())
				display.sleep();
		}
		display.dispose();
	}
}