With KWin master as of today the configuration of the Translucency Effect changed. It used to have translucency values in the area [0.0, 1.0] which got changed to [0, 100]. If you rebuild and just restart KWin it might be that you do not see any windows at all, because the windows are completely translucent.
To circumvent this problem run the KConfig Update application in $KDEDIR/lib/kconf_update_bin/kwin_update_settings_410 or just log out and log in again.
Users not running master are of course not affected by the change, the KConfig Update handles it correctly on first login after update.
Just wondering what would be the motivation for a such change?
The UI to set the opacity is using a slider from 0 % to 100 %. We changed from manual config logic to using KConfigXT. This means taking the configuration value directly from the UI component.
So we had to choose between changing the UI to no longer be in percentage or adjust the code. I thought that changing the code makes more sense.
I think it doesn’t. QML uses 0-1.0 for opacity values. If that’s different for compositor windows, it will just lead to confusion.
oh we still use the 0.0 to 1.0 internally. It’s just that the stored config value changed from what we use internally to what we show to the user.
Personally, I think 0.0 to 1.0 makes more sense. And you don’t need to change anything since 1.0 is 100%. It’s just stored differently to how it is displayed – the value is still the same, whereas 100 and 100% is completely different. The problem with 0 to 100 is that it is not intuitive that 100 is the maximum value, whereas translucency 100% should make it clear that it is fully translucent. Translucency 100 doesn’t really tell you anything until you look at the specs.
Reading your reply to the comment above it is clear I misunderstood you. Sorry.