Window positions under wayland

[Thiago Macieira]

On Thursday, 4 August 2022 16:01:23 PDT Carsten Haitzler wrote:
> there might be bigger picture ideas BEHIND that like "i have a password
> dialog for my db app" - then great. make that dialog as such and make sure
> the compositor knows what window it is a dialog for and a good
> wm/compositor will just magically open it centered over the parent window
> (or over the top center or bottom-right corner or whatever the policy that
> wm has for dialogs is - but at least it's now consistent for all apps with
> dialogs - if that is what the wm does - enforce consistency). if the
> wm/compositor does stupid things with dialogs and places them at $RANDOM
> positions then feel free to yell at the compositor for being stupid. there
> are very many fewer wm and compositors out there to yell at than there are
> applications to yell at, so it's more scalable to have the fixes put in
> compositors not apps. if you absolutely MUST have fine control over this ..
> as i said - you can render in-line in your window, use subsurfaces etc. but
> then you are limited as i described.

Indeed, this is mostly an X/Y problem.

You have an X problem (unrelated to X11, just using the letter of the 
alphabet) and you think you need Y to achieve it, as in the example above: in 
order to properly place some dialog, the application needed to get the 
absolute position of the window it's going to be relative to and then position 
the new window at a specific absolute position. So we get people coming and 
asking about how to do Y (this implementation).

Instead, we need to know what the X problem was: properly positioning the sub-
window or sibling window, or application window reappearing close to where 
you've last seen it. There are probably better ways of solving that problem 
than the reintroducing all the legacy that Carsten is talking about.

This is why Wayland developers keep saying that absolute positions being 
unavailable is a feature, not a bug. There may come a time when the number of 
protocol extensions to support all the little things that one could do with 
absolute positioning becomes a burden, but we're not there and have yet to see 
a problem that can't be solved differently.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel DCAI Cloud Engineering