/**
* Constructs a previewer part.
*/
public PreviewerPart() {
annPanel = new AnnotatedPanel();
annPanel.addSelectionHandler(new SelectionHandler<Annotation>() {
@Override
public void onSelection(SelectionEvent<Annotation> event) {
int line = Integer.valueOf(event.getSelectedItem().getValue());
CommandEvent.fire(new SystemJumpToLineCommand(line));