Subject: bug#31031: 27.0; (elisp) `Position Parameters', floating-point values

From: Robert Pluim <[email-masked]>
Date: Fri, 06 Apr 2018 12:28:38 +0200

Robert Pluim <[email-masked]> writes:

>>> D'oh. Of course, top is the right parameter to use. With that the
>>> frame switches monitor between top and bottom, so that would imply
>>> that the same switching should happen for "left". Iʼm undecided so far
>>> as to which I think is the "correct" behaviour.
>>
>> I'm not sure I understand.  Do you mean that when you change the value
>> of 'left' the frame always stays within the left monitor while when
>> you change 'top' the frame moves from the upper to the lower monitor
>> and back?  That would be queer.
>
> Iʼll have to retest this one, I may have missed a case.

Two monitors, one above the other, frame on bottom one.

(modify-frame-parameters nil '((top .   0.0)))
  => frame moves to top monitor
(modify-frame-parameters nil '((top .   1.0)))
  => frame moves tobottom monitor

Repeating those commands cycles between top and bottom monitor.

(and they're not flush to the edges, but this is with GDK scaling
going on, so Iʼm not too surprised by that).

Two monitors, one next to the other, frame on right one.

(modify-frame-parameters nil '((left .   0.0)))
  => frame moves to left monitor
(modify-frame-parameters nil '((left .   1.0)))
  => frame moves to right monitor

and again this cycles between the monitors. So whatever I tested
before, it wasn't this, and the behaviour is consistent between "left"
and "top".

I can't find anything in the elisp manual describing that the
workareas of the two monitors are combined like this.  Should such
information go in (elisp)Multiple Terminals, or (emacs)Multiple
Displays? Or both?

Robert