propose a optimised DARK mode for all gadgets

[andrasrcord]

Hello,
it will be interesting of propose a DARK mode, assuring than all gadgets background color will are BLACK.
The goal being to avoid any ocular fatigue and glare due to the white of the current "Friture" in a music studio context.
Actually, all gadgets background color remains in WHITE (except for the spectrogram gadget than him stay BLACK).
Tested on Kubuntu 20.04 / 21.10 for all Plasma settings.

[domichel]

Yep, I vote for this.

[tlecomte]

Support for a dark theme has been added in #295 😄

[domichel]

Thanks a lot. For this to work on my gentoo system, it was necessary to copy 2 files from qt5ct into the venv as explained here:
https://stackoverflow.com/questions/58675935/having-issues-getting-pyqt5-venv-qt5ct-to-play-nicely

$ cp /usr/lib64/qt5/plugins/platformthemes/libqt5ct.so /path/of/your_venv/lib/python3.11/site-packages/PyQt5/Qt/plugins/platformthemes/
$ mkdir /path/of/your_venv/lib/python3.11/site-packages/PyQt5/Qt/plugins/styles/
$ cp /usr/lib64/qt5/plugins/styles/libqt5ct-style.so /path/of/your_venv/lib/python3.11/site-packages/PyQt5/Qt/plugins/styles/

[domichel]

I think that on linux, it must be a very common issue, at least for users that don't use desktops like gnome or kde. Which imply it would be great to have a word about that into INSTALL.md.