private void trachViewChange(final GraphModel graphModel) {
untrackViewChange(graphModel);
if (model.getVisibleViewId() == -1) {
model.setVisibleViewId(graphModel.getVisibleView().getViewId());
}
graphListener = new GraphListener() {
public void graphChanged(GraphEvent event) {
if (event.is(GraphEvent.EventType.VISIBLE_VIEW)) {
if (model.getVisibleViewId() != graphModel.getVisibleView().getViewId()) {
//View has been updated