[Solved][Bug ?] Single/double click preference of desktop environment not used

[triplus]

OK i did some testing on Kubuntu 18.10 and first to set things straight. We are not talking about using the native file managers Nautilus/Dolphin, but about using native (GTK/KDE) file dialogs. Now as for Ubuntu (GTK). That seems to work just fine, enabling it, but as for using native KDE file dialog. That didn't work on Kubuntu 18.10. I did some additional tests (directly by using PySide) and couldn't enable the native KDE file dialog. Therefore i don't know if this should be possible or not and if it is supported by Qt. I was guessing it was. If it would be possible, then i am guessing such dialog could respect single/double click behavior, as set by the desktop environment (setting in KDE System Settings -> Desktop Behavior). This is only guessing.

But now back to your original question. I had to use double click, to for example enter a directory. Using the default FreeCAD Qt file dialog on Kubuntu 18.10. Therefore i wonder why this works differently on your side in the first place.

[openBrain]

OK i did some testing on Kubuntu 18.10 and first to set things straight. We are not talking about using the native file managers Nautilus/Dolphin, but about using native (GTK/KDE) file dialogs. Now as for Ubuntu (GTK). That seems to work just fine, enabling it, but as for using native KDE file dialog. That didn't work on Kubuntu 18.10. I did some additional tests (directly by using PySide) and couldn't enable the native KDE file dialog. Therefore i don't know if this should be possible or not and if it is supported by Qt. I was guessing it was. If it would be possible, then i am guessing such dialog could respect single/double click behavior, as set by the desktop environment (setting in KDE System Settings -> Desktop Behavior). This is only guessing.

But now back to your original question. I had to use double click, to for example enter a directory. Using the default FreeCAD Qt file dialog on Kubuntu 18.10. Therefore i wonder why this works differently on your side in the first place.

Honestly, some of your explanation are reaching the limits of my skills.
On my side I actually didn't expect file dialogs to be really different between the "FC one" and the "KDE one" as both are Qt based.
I can do some extra diag tests one my computer if needed (and if someone may tell me).

[triplus]

Yes, the assumption KDE file dialog will just work, due to KDE ties with Qt, and as GTK file dialog works. That assumption i guess didn't pan out. As for what you could test, ATM i don't have any suggestions, i more or less tested everything i could think of on Kubunut 18.10. Including things around xdg-desktop-portal (GTK/KDE). I guess things are just not there yet and hopefully that will change with some future Qt/KDE version.

Anyway, using native file dialog on KDE would likely expose issues, like the issue with missing extensions, as seen with the GTK file dialog. Until somebody would be prepared to tackle such issues i don't see native file dialogs as a viable option majority would use, over Qt based file dialog provided by default.

[openBrain]

Problem solved with the latest update of daily release.
---
OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15611 (Git)
Build type: Release
Branch: master
Hash: 64a94ae0f7c60fc981086fe157150a9c0dca29c6
Python version: 2.7.15rc1
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)