add support for platform-dependent skin styles + fix WEffectSelector styling

[Be-ing]

This will allow us to work around platform-dependent quirks in styling. For 2.1 this is needed to work around the issue of the checkmark pushing text to the right and getting cut off in WEffectSelector only on macOS.

[daschuer]

How does it work? Please add a short description to the source code and the wiki.

[Be-ing]

This allows the <Style> element in skin.xml (or for any other element in the skin but I don't intend to use that) to have src-mac, src-windows, and src-linux attributes to specify a platform-specific QSS file to override anything in the style.qss file for all platforms. Do you think this is a good approach for working around the issue of effect names getting cut off?

[Be-ing]

This may turn out to be useful for other problems in the future as well as the present issue with WEffectSelector.

[ronso0]

Could you test it for WEffectSelector?

[Be-ing]

macOS 1440 x 900 screenshots:

[Be-ing]

I double checked with #1592 merged in and the drop down menus still look good.

[Be-ing]

Defining the height and font size for WEffectSelector::item in Shade was breaking skin scaling. After that, I had to fix it again on macOS by hiding the checkmark:

[Be-ing]

GNOME at 250%:

[Be-ing]

KDE at 250%:
interestingly here the menus show below the widget instead of expanding above and below. This makes the font color of the loaded effect (WEffectSelector::checked) a little odd, but it's no big deal.




The font color of the selected item in Shade is difficult to read. I tried explicitly setting the font color of WEffectSelector::item:selected but it seemed the system color overrode that.

[Be-ing]

I'll merge this now to ensure the skins are in their final state for the screenshots in #1525 and so we can get builds to test on macOS with Retina screens and Windows.

[ronso0]

So I can remove the hack from Tango and bring back the tick mark?

[ronso0]

This went to RC1, right?
Text is still/again cut off in LateNight & Shade with minimal window width, scaled 100%.

[Be-ing]

So I can remove the hack from Tango and bring back the tick mark?

I think so, now that we have a way to hide it only on macOS.

This went to RC1, right?

Yes.

Text is still/again cut off in LateNight & Shade with minimal window width, scaled 100%.

🤦‍♂️ You are right. Would you like to take care of that?

[Be-ing]

Windows 7, 1366 x 768:

[ronso0]

@Be-ing This is how it looks right now on windows or is this your WIP fix?
I'm confused since on Linux the checkmarks are there. Tested with french locale.
In Tango it looks good (except the missing tick mark) because the effect selector has a right padding to work around issues with scaling, and is hidden underneath the effect toggle and effect name. That padding is apparently applied to QAbstractItemView and makes space for long names.

So I move the current qss snippets to style-win.qss as it looks good on Windows, and put the Mac fixes into style-linux.qss, as well. Alright?

[Be-ing]

Text is still/again cut off in LateNight & Shade with minimal window width, scaled 100%.

I can't reproduce this at 100% scaling on my 3840 x 2160 screen, neither in GNOME nor KDE... 😵

[Be-ing]

This is how it looks right now on windows or is this your WIP fix?

Those screenshots were taken on Windows 7 with RC build 6663.

[Be-ing]

So I move the current qss snippets to style-win.qss as it looks good on Windows, and put the Mac fixes into style-linux.qss, as well. Alright?

Do you mean keep the Mac fixes in style-mac.qss and make new style-linux.qss files?

[ronso0]

Those screenshots were taken on Windows 7 with RC build 6663.

Mine were taken with the same build. ubuntu studio 14.04 with xfce4.
Can try with vanilla Ubuntu and maybe up-to-date Ubuntu Studio later on..

[Be-ing]

Note that if you add other platform-specific style sheets you need to list them in the <Style> element in skin.xml as described above.

[ronso0]

fixed in #1596