Adapt to the latest Mutter API

[worldofpeace]

I've tested that it builds with mutter 3.34.1 and 3.28.4.
What I've done in SystemBackground.vala is probably totally incorrect. A suggestion is welcome on what we actually should be doing.

What I've done is adapted the changes in elementary/gala#566, as it's literally the code copy pasted mostly, to be used here.

Fixes #120.

It would be fabulous ✌️ if we could have everything adapted to latest mutter before the end of the year.

[Tireg]

Ok now I can confirm this works great since May 8, when I dropped the first patch (#120 (comment)).
Didn't encountered any issue from this time with greeter.
@worldofpeace has done a great work by adding this PR and adapting changes for newer mutter versions.

This would be great to have some review here as everything seems to work as expected.

[worldofpeace]

Ok now I can confirm this works great since May 8, when I dropped the first patch (#120 (comment)).
Didn't encountered any issue from this time with greeter.
@worldofpeace has done a great work by adding this PR and adapting changes for newer mutter versions.

This would be great to have some review here as everything seems to work as expected.

Thanks @Tireg, also thanks for tracking down all the issues so carefully in gala.
It's pretty important to me as a downstream to be able to support latest mutter API's and not hold compatibility packages.

[worldofpeace]

@tintou I did notice that the background with mutter 3.34 never got drawn...

[worldofpeace]

Will quote that

What I've done in SystemBackground.vala is probably totally incorrect. A suggestion is welcome on what we actually should be doing.

I believe there's something going on there.

[tintou]

@worldofpeace I just pushed a fix to this, It was because system_background.set_wallpaper (); wasn't called in the 3.34 version, I fixed it by setting the system wallpaper at object construction as it is done in Gala

[worldofpeace]

@worldofpeace I just pushed a fix to this, It was because system_background.set_wallpaper (); wasn't called in the 3.34 version, I fixed it by setting the system wallpaper at object construction as it is done in Gala

Thanks ✨

[tintou]

Thank you :)

[worldofpeace]

I'm not sure if elementary/gala#518 will also be present in the greeter. But if any fix makes its way there it probably should be ported here too.