gallery.addMouseTrackListener(new MouseTrackListener() {

			@Override
			public void mouseHover(MouseEvent e) {
				Gallery g = (Gallery) e.widget;
				GalleryItem item = g.getItem(new Point(e.x, e.y));
				
				addEffect(e, item);
				
				

			}

.....

	private void addEffect(MouseEvent e, GalleryItem item) {
		runner = new AnimationRunner();

		Rectangle src = item.getBounds();
		Rectangle dest = src;
		long lengthMilli = 700;
		IMovement movement = new LinearInOut();
		Runnable onStop = null, onCancel = null;

		GrowEffect effect = new GrowEffect(gallery, src, dest, lengthMilli, movement, onStop, onCancel);
		
		runner.runEffect(effect);
		

	}