Re: [dwm] snapping bugs with multiple screens

From: Matthias-Christian Ott <>
Date: Sun, 04 May 2008 10:32:39 +0200

John Li <> wrote:

> I'm not sure if this qualifies as a bug, but I think it's
> unexpected/non-optimal behavior.
> Example setup:
> Laptop screen at 1024x768 with a separate LCD at 1280x1024 positioned on
> the left of the laptop. Here's a geom for that:
> /* geometries, s{x,y,w,h} and bh are already initualized [sic] here */
> /* name bx by bw wx wy ww wh mx my mw mh tx ty tw th mox moy mow moh */
> DEFGEOM(desklap, 0, 0, 1280, 0, bh, sw, sh-bh, 0, bh, 1280, wh, 1280, 0, 1024, 768, 0, bh, mw, wh)
> I have the bar and master area confined to the first 1280 horizontal
> pixels: the separate LCD. The master area is 1280x(1024-bh) while the
> tile area is 1024x768. There are two unexpected behaviors related to
> snapping in the tile area:
> 1) Snapping at the top doesn't snap to the top of the tile area, y=0; it
> snaps to y=bh.
> 2) Snapping at the bottom doesn't snap to y=768; it snaps to y=1024.
> Since I've defined ty=0 and th=768, this seems incorrect. I don't know C
> very well, but it seems like dwm looks at only at the w? vars (and not
> the m? or t? vars) to determine when to snap. Changing those would
> result in wrong snapping behavior on either the master or tile areas,
> though.
> Another possible, vaguely related bug: there is no snapping on the
> master/tile split (also the physical divide between the monitors).
> Perhaps if mw is a constant, or doesn't include "mfact", there could
> also be snapping here?
> I know dwm isn't particularly concerned with heavy use of floating
> windows, but I find them necessary at times (especially with higher
> resolution, multiple monitor setups) so it'd be nice to see snapping
> work in these situations.

I'm not that familiar with Xinerama, but the screen is always a
rectangular, so there is some dead space the window manager has to be
aware of [1]. Seems to me like dwm isn't.

But anyhow is there a reason why dwm still uses Xinerama instead of
XRandR. [1] states that it's deprecated in favor of XRandR.

> dwm is great software. Thanks!
> -john


Received on Sun May 04 2008 - 10:32:57 UTC

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