code: public void onDoubleClick(DoubleClickEvent event) {
  		//Check if there was a last click that was handled in this class.
  		if (null != lastClickPosition) {
  			// Zoom in on the event location.
  			Bbox bounds = mapWidget.getMapModel().getMapView().getBounds();
  			double x = lastClickPosition.getX() - (bounds.getWidth() / 4);
  			double y = lastClickPosition.getY() - (bounds.getHeight() / 4);
  			Bbox newBounds = new Bbox(x, y, bounds.getWidth() / 2, bounds.getHeight() / 2);
  			mapWidget.getMapModel().getMapView().applyBounds(newBounds, ZoomOption.LEVEL_CHANGE);
  		}
  	}
docs: Zoom in to the double-clicked position.