def slider_position(self):
		"""The current position of the slider on the tool,
		normalized to the range [-1, 1] and whether it has changed in this
		event.

		The logical zero is the neutral position of the slider, or
		the logical center of the axis. This axis is available on e.g.
		the Wacom Airbrush.

		If this axis does not exist on the current tool, this property is
		(0, :obj:`False`).

		Returns:
			(float, bool): The current value of the the axis.
		"""

		position = self._libinput. \
			libinput_event_tablet_tool_get_slider_position(self._handle)
		changed = self._libinput.libinput_event_tablet_tool_slider_has_changed(
			self._handle)
		return position, changed