Re: [dwm] patch: fix screen flicker with monocle

From: Donald Chai <>
Date: Tue, 9 Sep 2008 20:41:00 -0700

On Sep 8, 2008, at 2:09 AM, Anselm R Garbe wrote:

> 2008/9/8 Donald Chai <>:
>> Actually, this is a totally unrelated problem. The problem is that
>> XGrabKeyboard generates focus events (XGrabKeyboard is called by
>> the X
>> server after establishing the passive grab with XGrabKey).
>> So, all keyboard shortcuts cause the window under the mouse to
>> briefly get
>> focus. I've used Metacity (the GNOME WM) with focus-follows-mouse,
>> and it
>> doesn't have this behavior when I Alt-Tab.
> I can't see why grabbing keys is an issue here. focus() only triggers
> a button grab on the old and new client which might causing this issue
> here. In Gnome WM you don't see this, because button grab's aren't
> necessary on a focus() basis, since it reparents the client windows
> and hence can keep the passive button grab for the whole lifetime of a
> client window on the frame window. So I fear, you/we have to live with
> this side effect.

I find it strange that the extra focus events only happen for me; or
maybe I'm just the only one who's bothered by it. (I see the same
thing in wmii and awesome too.)

 From looking at the ion2 code, I figured out that XGrabKey with
grab_window=root is the cause of the problem. If I instead call
XGrabKey on all of root's children, no spurious focus events are
generated. The following patch seems to fix things.

I add my own background layer to capture keypresses, so "xsetroot -
bg" will no longer work. :(

Received on Wed Sep 10 2008 - 03:41:00 UTC

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