set-frame-position - is it a bug?

set-frame-position - is it a bug?

[Friedrich Laher]

the intetion of the following code

 (setq fpx (cdr (assoc 'left (frame-parameters))))
  (setq fpy (cdr (assoc 'top  (frame-parameters))))

  (setq fpx (+ 1 fpx))

  (set-frame-position (next-frame) fpx fpy)

is to move the frame honizontally 1 pixel right;
but as a side-effect I get a vertical move as well.

Is there something wrong with my code?

Re: set-frame-position - is it a bug?

[Pascal Bourguignon]

Friedrich Laher <mathefritz@schmieder-laher.de> writes:
> the intetion of the following code
>
>  (setq fpx (cdr (assoc 'left (frame-parameters))))
>   (setq fpy (cdr (assoc 'top  (frame-parameters))))
>
>   (setq fpx (+ 1 fpx))
>
>   (set-frame-position (next-frame) fpx fpy)
>
> is to move the frame honizontally 1 pixel right;
> but as a side-effect I get a vertical move as well.
>
> Is there something wrong with my code?

No.  IMO it's a bug in the interaction between emacs and the window manager.

With my version of emacs "22.0.50.1", and with my window manager
(WindowMaker), it works as you want.

You could use:

(defvar fpx-compensation 0)
(defvar fpy-compensation -1)

  (setq fpx (cdr (assoc 'left (frame-parameters))))
  (setq fpy (cdr (assoc 'top  (frame-parameters))))
  (setq fpx (+ 1 fpx fpx-compensation))
  (setq fpy (+ 1 fpy fpy-compensation))
  (set-frame-position (next-frame) fpx fpy)

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
I need a new toy.
Tail of black dog keeps good time.
Pounce! Good dog! Good dog!

RE: set-frame-position - is it a bug?

[Drew Adams]

    the intention of the following code
      (setq fpx (cdr (assoc 'left (frame-parameters))))
      (setq fpy (cdr (assoc 'top  (frame-parameters))))
      (setq fpx (+ 1 fpx))
      (set-frame-position (next-frame) fpx fpy)
    is to move the frame honizontally 1 pixel right;
    but as a side-effect I get a vertical move as well.
    Is there something wrong with my code?

The code looks OK to me.

Is your menu-bar (or tool-bar) wider than your frame, so that it wraps
around? That will cause the behavior you describe.

Actually, now that I think of it, we should probably consider this an Emacs
bug, so I'm cc'ing the emacs-devel list. Thanks for bringing this up - I've
been aware of it for a long time, but it never occurred to me to file a bug.

Bug: If menu-bar is wider than frame, so it wraps, then set-frame-position
gets it wrong, in the manner described above.

RE: set-frame-position - is it a bug?

[Drew Adams]

>From Pascal Bourguignon:
    IMO it's a bug in the interaction between emacs and the
    window manager. With my version of emacs "22.0.50.1", and with
    my window manager (WindowMaker), it works

In my version of 22.0.50.1 and window manager (Windows XP), it's broken:

In GNU Emacs 22.0.50.1 (i386-mingw-nt5.1.2600)
 of 2005-06-26 on NONIQPC
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc
(3.3) --cflags -I../../jpeg-6b-3/include -I../../libpng-1.2.8/include -I../.
./tiff-3.6.1-2/include -I../../xpm-nox-4.2.0/include -I../../zlib-1.2.2/incl
ude'

BTW, this is not something new. The problem is also present in Emacs 20.