Re: Fwd: Wayland design principles (Re: wayland and gambas)

[Rolf-Werner Eilert <rwe-sse@xxxxxxxxxx>]

Am 30.04.24 um 01:40 schrieb Jussi Lahtinen:
>     If you do not have a coordinate system you can point to, you still MUST
>     have some way of telling the window manager where (about) you wish
>     it to
>     show something up and how.
>
>     Maybe there is an indirect way like telling it "please show this window
>     in 33% of the current screen size somewhere in the center". Otherwise,
>     wayland would only be able to serve frameless windows in
>     whole-screen-mode, like on mobiles or - as he put it - on car screens.
>     But it runs on normal screens with windows with all widgets, so how is
>     it achieved?
>
>     On a printed page, you usually count mm and the printer system will
>     translate this into pixels for its individual wand. There must be
>     such a
>     way in Wayland too - and Pekka does mention a translation layer for
>     older applications. It's just a shame they seem to realize this only
>     now.
>
>
> This is a good point. I wonder how it will work without knowing the 
> pixel coordinates.
> Definitely not my area of expertise.
>
> Jussi

Another thing that just came into my mind. Imagine you have a 4K 
display. First thing the graphical system has to look at is if it is 
part of a usual PC-like system with dedicated keyboard, mouse etc., or a 
touch screen (maybe a Look-for-a-shop system in a mall) or a 
display-only for advertisements or time schedules. This information will 
have to be obtained from the OS and decides whether to show the window 
title bars and gadgets or just showing the active window in full-scale 
in the front.

Then the second question is: "How big or small is the distance from 
display to user?" Maybe we are on 4K on an ultrasharp display in an 
office, or this is a large display where people are at least 4 m away. 
In the first case the windows and graphical elements can be scaled to a 
size that anyone sitting in front of any display is used to. In the 
latter case the elements will perhaps have to be enlarged, you cannot 
show so many of them at one time etc.

It could be a large benefit to the programmer not having to care for any 
and all cases. But if it is desired to have some control on certain 
types of screens, there should be a way of influencing the behaviour, at 
least an indirect one. Like I said before, this could be done specifying 
some relation to other known parts of the program window, like "25 % the 
size of the main window and in its lower right corner".

On the other hand, a quick workaround for me would be to just pack all 
elements for one application into a single window (like the colour 
palette window someone mentioned) in a way I still can control. This 
would be at least a workaround for ordinary application forms.

Regards
Rolf