public abstract class TreeCollapseAllActionBase extends AnAction {
public void actionPerformed(AnActionEvent e) {
TreeExpander expander = getExpander(e.getDataContext());
if (expander == null) return;
if (!expander.canCollapse()) return;
expander.collapseAll();
}
protected abstract TreeExpander getExpander(DataContext dataContext);
public void update(AnActionEvent event) {