Connects/Disconnects to the painted event of the editor.

        :param state: Enable state

def on_state_changed(self, state):
        """
        Connects/Disconnects to the painted event of the editor.

        :param state: Enable state
        """
        if state:
            self.editor.painted.connect(self._paint_margins)
            self.editor.key_pressed.connect(self._on_key_pressed)
            self.editor.repaint()
        else:
            self.editor.painted.disconnect(self._paint_margins)
            self.editor.key_pressed.disconnect(self._on_key_pressed)
            self.editor.repaint()