Method step

src/override/MenuBar.cpp:346–350

		struct UndoItem : ui::MenuItem {
			void step() override {
				text = "Undo " + APP->history->getUndoName();
				disabled = !APP->history->canUndo();
				MenuItem::step();
			}
			void onAction(const ActionEvent& e) override {
				APP->history->undo();
			}