I strongly disagree with some points made in the document:
> Window borders Do them in the application library!
Client side decorations have the huge disadvantage that you can't easily close unresponsive applications. To do so would need the compositor to somehow detect if an application has crashed or not which means nothing less than literally solving the halting problem.
> in particular, allthe X facilities for supporting window managers I would just flush.
In retrospect this is a huge mistake. Some niche window managers today have a more active community than the whole Wayland ecosystem. In fact the most popular haskell program is a window manager. So something must be right about enabling the modularity that makes window managers possible.
> Client side decorations have the huge disadvantage that you can't easily close unresponsive applications. To do so would need the compositor to somehow detect if an application has crashed or not which means nothing less than literally solving the halting problem.
You can close unresponsive applications whether they repaint their decorations or not; anyway, chances are, that when they don't repaint their decorations, they won't process your WM_DELETE_WINDOW anyway.
What you can't do without CSD is synchronized painting of decorations and window content. With CSD, you can have pixel-perfect window, without it, you have to coordinate between several processes and chances are you won't do it all in 16,6 ms (for 60 Hz).
> Some niche window managers today have a more active community than the whole Wayland ecosystem.
Sorry, no. Wayland is quite big now, just some niche DEs ignore it, due to lack of manpower, not by principle.
> In fact the most popular haskell program is a window manager.
If I had to guess, I would say that the most popular haskell program is a batch document converter. It is used ouside X11 too. Not that haskell usage is an relevant popularity indicator.
> So something must be right about enabling the modularity that makes window managers possible.
There are wayland compositors aiming exactly for that. See Sway.
> Window borders Do them in the application library!
Client side decorations have the huge disadvantage that you can't easily close unresponsive applications. To do so would need the compositor to somehow detect if an application has crashed or not which means nothing less than literally solving the halting problem.
> in particular, allthe X facilities for supporting window managers I would just flush.
In retrospect this is a huge mistake. Some niche window managers today have a more active community than the whole Wayland ecosystem. In fact the most popular haskell program is a window manager. So something must be right about enabling the modularity that makes window managers possible.