/**
* Initializes this model. Adds the listeners to the history browser.
*/
private void init() {
historyBrowserInterface.getHistoryBrowser().addListener
(new HistoryBrowserAdapter() {
public void executePerformed(HistoryBrowserEvent event) {
CommandNamesInfo info =
(CommandNamesInfo) event.getSource();
String details = UNDO_TOOLTIP_PREFIX
+ info.getLastUndoableCommandName();