Compositing in AppVMs

[jimmy....@gmail.com]

I really like transparent Terminal windows and would like to use them in AppVMs. They work on the dom0 Terminal, no sweat. But when I try to set the Background to transparent in the Terminal Preferences in any Fedora-24 AppVM I get: "Sorry, your Window Manager does not support compositing: Opacity setting is not available."

I'm using xfce-terminal in my AppVMs, same as dom0. The version numbers are different, but both offer the option of transparent backgrounds. It just doesn't seem to work in the AppVMs like it does in dom0.

I have Enable Display Compositing checked in the Window Maanger Tweaks for dom0. Is this supposed to affect AppVMs, too? Or do I need to set that within the AppVMs themselves? If the latter, I'm not sure how to get Windows Manager Tweaks running in AppVMs; maybe I'm blind, but I just don't find it anywhere and don't seem to be figuring out the right package name to run it from the CLI.

Any information, ideas, solutions about this would be most appreciated. :-)

[Alex]

On 03/04/2017 04:54 AM, jimmy....@gmail.com wrote:
> I really like transparent Terminal windows and would like to use them
> in AppVMs. They work on the dom0 Terminal, no sweat. But when I try
> to set the Background to transparent in the Terminal Preferences in
> any Fedora-24 AppVM I get: "Sorry, your Window Manager does not
> support compositing: Opacity setting is not available."

AFAIR, having transparent/semitransparent windows from AppVMs is a
potential security problem: rogue software may overlay hard-to-spot
windows on top of legitimate software to get confirmations/other actions
performed by an unsuspecting user.

So if something like this gets ever implemented in the GUI daemon (maybe
when wayland is supported?), I hope that I can disable the
functionality; it would be even better if that was disabled by default,
and had to be turned on by the user.

--
Alex

[Unman]

Also, all the window effects you see are implemented in the GUI domain,
currently dom0, and there are a number of effects that aren't supported
there. (e.g flashing alerts are not propagated to dom0 as another suer
has pointed out.) I think that window opacity is one of these, and as
Alex suggests, that's a good thing.