Re: USPosition vs. PPosition with Virtual viewports

[Lubos Lunak <l lunak suse cz>]

Dne čt 20. října 2005 03:29 Carsten Haitzler napsal(a):
> On Wed, 19 Oct 2005 15:30:00 -0500 Sasha Vasko <sasha aftercode net> 
babbled:
> > There is a certain ambiguity in how geometry should be specified by
> > user, when Window Manager is supporting virtual viewports. This surfaced
> >   as the result of GIMP abuse of USPosition flag which is outlined here
> >
> > : http://bugzilla.gnome.org/show_bug.cgi?id=319099
> >
> > Basically, for user to be able to place , say, a term window into
> > arbitrary viewport on the desktop, using just a command-line options -
> > geometry must be specified in relation to the desktop origin, there is
> > no other way around it. Therefore it is a duty of a Window Manager to
> > always treat USPosition in relation to a desktop origin.
> >
> > On the other hand, as apps itself may not be aware of existence of
> > virtual viewports, and even if they do - its not possible to reliably
> > take it into consideration - PPosition must always be treated in
> > relation to the current viewport's origin.
> >
> > Now this is not a transparent conclusion for anyone not involved with
> > window management to a certain depth, and therefore I suggest that this
> > should be clarified in specs under "Desktop/workspace model" subsection
> > of Implementation notes.
> >
> > Anybody wants to comment on that ?
>
> this is a tough one. most existing apps will see BOTH USPosition and
> PPosition as ROOT window relative co-ordinate hints (out of practicality
> and a loong history). changing this will mean breakage of at least some
> apps. but this also makes using a virtual desktop + movable viewport a bit
> of a nightmare,as i assume you are discovering.
>
> basically a lot of wm's have ignored pposition in the past due to abuse by
> apps (like netscape) and thus many aps have moved to abusing usposition
> instead (though they do it better than netscape did). i know that
> personally im gettigng to the point of encouraging users to use the lock
> and override features of the wm to say "dont listen to the apps request for
> position, size etc. use mine and ignore the app" as its geenralyl more
> reliable :) thus in that scneario - the wm can choose to put the app where
> it was last - relative to the virtual desktop co-ordinates, not the
> viewport. :)

 Does somebody think it wouldn't be completely naive to try to fix this 
USPosition/PPosition madness by adding some kind of I-do-it-properly property 
that both WMs and apps could set?

 Qt also sets both US and P positions, because of the reasons listed above, in 
order to work around broken old WMs and whatnot, and I've run already into 
this a couple of times with KWin. Qt e.g. always places dialogs, and although 
KWin has much better placement algorithm it's simply not of much use because 
of US and P position set. I even tried to actually ignore those flags in 
general for dialogs but that wasn't that good idea either :( . And having the 
user to manually set setting for every app is not really a solution.

-- 
 Lubos Lunak
 KDE Developer