markElem.getStyle().setLeft(fraction * 100, Unit.PCT);
markElem.getStyle().setProperty("borderColor", color.toString());
parent.appendChild(markElem);
listenerOwner.manageEventListener(MouseOverEvent.addMouseOverListener(
this, markElem, new MouseOverListener() {
public void onMouseOver(MouseOverEvent event) {
calloutModel.update(offset, 0, shortDescription, 0, true);
}
}));