Mac OS Catalina dark mode wreaks havoc on readability when changed while running

[ebernet]

Please provide the following information

qBittorrent version and Operating System

qBittorrent v4.2.3 (64-bit), macOS Catalina 10.15.4 (19E266) but seen on last version of Catalina

If on linux, libtorrent-rasterbar and Qt version

(type here)

What is the problem

If you change display mode (either manually or by having it change automatically at specific times of day), the qBittorrent display is unreadable without highlighting items.

What is the expected behavior

I expect qbittorrent to properly utilize the display rendering for the current mode of Mac OS. The display setting is there (available properly in the app) because if you quit and relaunch the qbittorrent client it presents the proper mode (In dark mode, white font on dark/grey background, in light mode, black text on white/light grey background)). I have the mode set to automatic and I need to quit and relaunch the app to be able to read it.

Steps to reproduce

Run qBittorrent, go into System preferences and change the display mode. Examine the screen and see what it looks like.

Extra info(if any)

Seems like a fairly easy issue to fix, but currently requires me to either highlight all the items or quit and relaunch the app so as to be readable

[FranciscoPombal]

Please post screenshots.

[ebernet]

This first one is if I switch (or am switched) to dark mode while qBittorrent is running

While this is the expected behavior (what I get if I quit and relaunch qBittorrent)

This is what I get if I switch to light mode...

And this is what I expect to see...

[ebernet]

I guess it is a font color issue, not the UI overall. You change the UI color, but not the font color.

[FranciscoPombal]

Looks like a Qt bug. @Kolcha thoughts?

[ebernet]

Interesting that it is not an issue in the bordering interface, only in the table view. Buttons, sidebar, and tool bar all properly change the font color.

[Kolcha]

AFAIK, Qt still doesn't handle theme change, app must be restarted after that.
but I can be wrong, last Qt version I tried was 5.12.5, I'll try it with simple app build using newer Qt

[jagannatharjun]

it qbittorrent's bug(?), following #11708 the colors are decided at startup
maybe @glassez can help?

EDIT: sorry this seems my own doing #11433, I don't know if we want this behaviour, @glassez(?)

[FranciscoPombal]

@jagannatharjun if that is the case, it would be best if that PR didn't have to be reverted to fix this IMO, otherwise it would break themeing for a lot of users right?

[jagannatharjun]

This can be fixed easily, but you have to ask maintainers if they want this behaviour

[glassez]

if they want this behaviour

IIRC, it was lost unintentionally, so why shouldn't we restore it?
As far as I understand, we are talking about using the default theme (in this case, the application can follow system wide dark mode, and it can be switched in runtime).

[ebernet]

I believe this is a bug in qBittorrent, not in QT. I have other apps that use QT and the theme and don't suffer from this problem (for example, EiskaltDC++). The thing that also tells me it is a bug is because if you quit and relaunch the app, it displays properly. Basically everything properly changes to the correct colors OTHER than the font in the table view, but it does change to the proper color when launched anew... Thank you :)

[glassez]

This can be fixed easily

Seems not so easy if you intend to keep current way of loading colors from stylesheet...

[maboroshin]

Qt seems to be able to change the theme without restart. e.g. QuiteRSS.

[glassez]

Fixed by #12755.