Method undo

SLiCAP/schematic/canvas.py:998–1002

(self)

        self.data_changed.emit()

    def undo(self) -> None:
        if not self._undo_stack:
            return
        self._redo_stack.append(self.to_data())
        self._restore(self._undo_stack.pop())

    def redo(self) -> None:
        if not self._redo_stack: