/**
* Insert a new ui component into the panel.
*
* @param handler The handler associated with this component.
*/
private void addToHistory(XmlHandler handler) {
int howManyToRemove = handlers.size() - historyIdx - 1;
for (int cnt = 0; cnt < howManyToRemove; cnt++) {
Misc.removeLast(handlers);
}
handlers.add(handler);
historyIdx = handlers.size() - 1;
checkButtons();
}
