[news.eclipse.platform.swt] Event bubbling

[OndÅej KuÄera <ondrej.kucera@xxxxxxxxxx>]

Hello,

I'm sort of new to SWT (and definitely new to this newsgroup), although  
after reading some material, writing a few code samples and going through  
almost all the official snippets I think I know the basics. But I can't  
figure out something about the event handling and can't find a decent  
article or something that would go deeper then simple telling how to add a  
listener (typed or untyped) and how to write a simple one.
I'm mostly familiar with the event model of web browsers as stated in DOM  
2 Events specification where there's possible either event capturing or  
event bubbling - for example if there is a list item (LI) inside an  
unordered list (UL) inside the body of the document and user clicks over  
the list item, this event can be caught on all of these elements (LI, UL,  
BODY), some of them or none of them (bubbling vs. capturing only differs  
in the order of the call of the appropriate event handlers).
I desperately need to do something like that in SWT, but I don't know how.  
For example I need to catch every MouseDown over o Composite, whether it  
is an empty Composite or it is full of Labels. If I try the code below and  
I click somewhere in the Label, only the Listener for the Label is called  
(and not the ones for Group, Composite and Shell). I thought the the rest  
would be called automatically but they're obviously not, so I was  
wandering that maybe I should "do something" to the event in the Listener  
to pass the event to the widget's parent but just from looking to the  
javadoc documentation I couldn't figure out what would do the trick. Or  
maybe I'm going completely wrong direction but I really need to solve this.

Regards, OndÅej


import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.widgets.*;

public class EventExample {

    public static void main (String[] args) {
	Display display = new Display();
	Shell shell = new Shell(display);
	Composite composite = new Composite(shell, SWT.BORDER);
	Group group = new Group(composite, SWT.NONE);
	group.setText("group");
	Label label = new Label(group, SWT.BORDER);
	label.setText("label");
	label.pack();
	label.setLocation(10, 100);
	group.setSize(100, 200);
	group.setLocation(10, 100);
	composite.setSize(200, 300);
	composite.setLocation(10, 100);
	shell.setSize(300, 450);

	Listener listener = new Listener() {
		public void handleEvent(Event event) {
		    if (event.type == SWT.MouseDown) {
			System.out.println("MouseDown: " + event.widget.toString());
		    }
		}
	    };

	shell.addListener(SWT.MouseDown, listener);
	composite.addListener(SWT.MouseDown, listener);
	group.addListener(SWT.MouseDown, listener);
	label.addListener(SWT.MouseDown, listener);

	shell.open ();
	while (!shell.isDisposed()) {
	    if (!display.readAndDispatch ()) display.sleep ();
	}
	display.dispose ();
    }
}