GUI issue if dpi scale factor≠1

[poautran]

In GitLab by @Polack on Oct 21, 2025, 14:41 GMT+2:

Issue on Ubuntu 24.04 using X11/GNOME.

If the scaling factor is different than 1 (can be changed in Fonts of Gnome Tweaks), then the GUI becomes unusable (I am on 0.62, but even 0.95 has issues).

Migrated from GitLab: https://gitlab.esrf.fr/workflow/ewoks/ewoksorange/-/issues/63

[poautran]

In GitLab by @Polack on Oct 21, 2025, 14:45 GMT+2:

[poautran]

In GitLab by @payno on Oct 21, 2025, 15:02 GMT+2:

mentioned in issue workflow/ewokstutorials/ewoksfordevs#25

[poautran]

In GitLab by @Polack on Oct 22, 2025, 11:48 GMT+2:

Ok, if I do

export  QT_AUTO_SCREEN_SCALE_FACTOR=0

The issue disappears.

It also disappears if I remove lines

        if ns.enable_high_dpi_scaling \                                                                                                                                                                                                                                                                                                                                                     
                and hasattr(Qt, "AA_EnableHighDpiScaling"):                                                                                                                                                                                                                                                                                                                                 
            # Turn on HighDPI support when available                                                                                                                                                                                                                                                                                                                                        
            QApplication.setAttribute(Qt.AA_EnableHighDpiScaling) 

of file orangecanvas/application/application.py.

So not sure if this is really a bug, or an issue with how Gnome deals with scaling.

[poautran]

In GitLab by @Retegan on Oct 23, 2025, 22:30 GMT+2:

@Polack What Qt binding are you using?

[poautran]

In GitLab by @Polack on Oct 23, 2025, 23:02 GMT+2:

pyqt5
(I tried pyqt6 and pyside6, but it did not launch if i remember correctly.)

[poautran]

In GitLab by @Retegan on Oct 24, 2025, 08:28 GMT+2:

PyQt6 should work and will probably solve your issue. Try pip install ewoksorange pyqt6 in a new Python env.

[poautran]

In GitLab by @Polack on Oct 27, 2025, 09:10 GMT+1:

Indeed it does. Although I needed to delete completely my old venv, otherwise removing pyqt5 and installing pyqt6 gave:

2025-10-27 09:05:30,456 - ewoks._engines - WARNING  - Unable to properly load 'orange' engine. Error is No module named 'PyQt5.QtCore'
Traceback (most recent call last):
  File "/homelocal/ep283511/ewoksfordevs/.venv/lib/python3.12/site-packages/ewoks/__main__.py", line 68, in command_execute
    results = execute_graph(graph, engine=args.engine, **args.execute_options)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/homelocal/ep283511/ewoksfordevs/.venv/lib/python3.12/site-packages/ewoks/bindings.py", line 73, in execute_graph
    engine_api = _engines.get_execution_engine(engine)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/homelocal/ep283511/ewoksfordevs/.venv/lib/python3.12/site-packages/ewoks/_engines.py", line 47, in get_execution_engine
    raise RuntimeError(f"No engine found for graph execution: '{engine_name}'")
RuntimeError: No engine found for graph execution: 'orange'