Issue:Touch screen locks up when touching within a GEM window in puredata graphic patches.

[ronsum]

Describe the issue

Touch screen locks up and wont respond when touching inside a puredata GEM window of graphics patches.

To Reproduce

Steps to reproduce the behavior:

1. Go to...Main Menu
2. Click on...Add Special Chain
3. Click on...PureData
4. Click on...Any Midi Channel
5. Click on...graphics
6. Click on...LissajousZ
7. Change controllers using touch screen
8. Touch anywhere inside the GEM window (where you see the lassajous patterns

Expected behaviour

be able to continue to use the touch interface to change values or select buttons

Actual behaviour

The touch screen locks up and wont respond

Debugging Log:

Dec 24 19:05:38 zynthian startx[1295]: Exception in thread Multitouch:
Dec 24 19:05:38 zynthian startx[1295]: Traceback (most recent call last):
Dec 24 19:05:38 zynthian startx[1295]: File "/usr/lib/python3.11/threading.py", line 1038, in _bootstrap_inner
Dec 24 19:05:38 zynthian startx[1295]: self.run()
Dec 24 19:05:38 zynthian startx[1295]: File "/usr/lib/python3.11/threading.py", line 975, in run
Dec 24 19:05:38 zynthian startx[1295]: self._target(*self._args, **self._kwargs)
Dec 24 19:05:38 zynthian startx[1295]: File "/zynthian/zynthian-ui/zyngui/multitouch.py", line 254, in _run
Dec 24 19:05:38 zynthian startx[1295]: self._process_evdev_events()
Dec 24 19:05:38 zynthian startx[1295]: File "/zynthian/zynthian-ui/zyngui/multitouch.py", line 281, in _process_evdev_events
Dec 24 19:05:38 zynthian startx[1295]: self._process_touch_events()
Dec 24 19:05:38 zynthian startx[1295]: File "/zynthian/zynthian-ui/zyngui/multitouch.py", line 328, in _process_touch_events
Dec 24 19:05:38 zynthian startx[1295]: event.offset_x = event.widget.winfo_rootx()
Dec 24 19:05:38 zynthian startx[1295]: ^^^^^^^^^^^^^^^^^^^^^^^^
Dec 24 19:05:38 zynthian startx[1295]: AttributeError: 'NoneType' object has no attribute 'winfo_rootx'

Configuration

Hardware

Raspberry Pi 4 Model B Rev 1.1
Audio: HifiBerry DAC+ light
Display: Generic HDMI/DSI Display (RPI official 7" touchscreen)
Wiring: DUMMIES
I2C: Not detected
Profile: 

System

Debian GNU/Linux 12 (bookworm)
Build Date: 2024-09-11
Memory: 24% (451M/1846M)
SD Card: 13% (15G/117G)
Temperature: 63.7ºC
Overclock: None

MIDI & UI

Tuning: 440 Hz
Master Channel: Off
Preload Presets: On
ZS3 (SubSnapShots): On
Power Save: 10 minutes
Audio Levels on Snapshots: On

Software

zyncoder: oram (66fa477) 
zynthian-ui: oram (2ed5a43)
zynthian-sys: oram (d8e0202)
zynthian-data: oram (305b301)
zynthian-webconf: oram (8ec693a)