You can achieve this by writing a small script to toggle "device enabled" property of the multi-touch input device. You can then bind this script to one of the keys for easy access or just execute it using any other method you prefer.
First you need to get the device name using xinput
utility. Open a Terminal and type xinput list
.
:~$ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ Wacom ISDv4 E6 Pen stylus id=10 [slave pointer (2)]
⎜ ↳ Wacom ISDv4 E6 Finger touch id=11 [slave pointer (2)]
⎜ ↳ TPPS/2 IBM TrackPoint id=14 [slave pointer (2)]
⎜ ↳ Wacom ISDv4 E6 Pen eraser id=16 [slave pointer (2)]
⎜ ↳ SynPS/2 Synaptics TouchPad id=13 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Sleep Button id=8 [slave keyboard (3)]
↳ Integrated Camera id=9 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=12 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=15 [slave keyboard (3)]
As you can see in this case the name of multi touch device is Wacom ISDv4 E6 Finger touch and its id is 11. Yours may be different. You can use the id as well, but I prefer the name since adding/removing devices could cause the id of some of the devices to change. Here is an example script that could get you started. All this does is toggle between two commands -- one to enable the multitouch device and one to disable it.
#!/bin/bash
#!/bin/sh
# This script can be used to toggle enable state of wacom multitouch screen for
# Thinkpad Tablet Series. You may need to change the name of multitouch device
# which can be found by running *xinput list* command
TOGGLE=$HOME/.multitouch_toggle
if [ ! -e $TOGGLE ]; then
touch $TOGGLE
xinput set-prop 'Wacom ISDv4 E6 Finger touch' 'Device Enabled' 0
else
rm $TOGGLE
xinput set-prop 'Wacom ISDv4 E6 Finger touch' 'Device Enabled' 1
fi
I hope this will help you get around the problem for now. If you need any help with customizing or running the script above feel free to ask.