Could this potentially open up the possibility of implementing a user-level desktop session serialization and restoration feature? Similar to how Emacs handles per-directory sessions.
> Plasma developer David Edmundson demonstrates how a desktop using Wayland, Qt6 and KWin can recover from a catastrophic crash as if nothing had happened.
> You will lose no data, the video you were watching will not skip a frame, and the contents of your clipboard will remain intact.
> The same principles can be applied to jumping from one desktop environment to another, for example, from Plasma to Gnome...
> ... And can provide a way to save _the state_ of an application to disk, stopping the app in its tracks and removing it from memory, so that later you can restore it just where you left off.
This is more or less what we once dreamed of doing with Activities in KDE 4, but couldn't make it work on X11 - we were banking on the X11 session handling protocols to implement the suspend/restore, only to find that few if any toolkits and apps implemented them properly, and that fixing this wasn't going to be viable due to a lot of spaghetti all over the place.
This is partly why Activities ended up feeling somewhat redundant to Virtual Desktops. But if you go back to those early 4.x releases, you will find that the Pause/Unpause buttons etc. on Activities were featured rather more prominently.
As David describes in the blog post, things in Wayland are a lot more nicely layered. In part, toolkits have also seen architecture cleanup as a side effect of having to support multiple backends during the transition, and code has become more hackable and modular as a result.
Interesting. I played with Activities for a while when they were introduced, but I've never understood what value they provide. I still don't, to be honest. But perhaps it's because they weren't able to provide value?
