[xmonad] Pointer follows focus (with patch)

[lithis]

On Sat, 2008/02/16 17:31:11 -0600, Spencer Janssen wrote:
> On Sat, Feb 16, 2008 at 12:26:18PM -1000, lithis wrote:
> > On Thu, 2008/02/07 15:35:48 -0600, Spencer Janssen
> > wrote:
> > > Have you considered using logHook?  It is executed
> > > after each windowset change,
> > > which should be sufficient.
> > 
> > I tried this, but the pointer warps too often: any time
> > the
> > pointer enters a window, it immediately warps to the
> > specified position in the window. Also, the pointer
> > warps
> > any time the window title changes.
> 
> So check the pointer position first, if it is contained in
> the focused window,
> do nothing, otherwise warp to whichever position.

I could’t figure out how to do this. Could anyone who knows
Haskell and X11 write a function that does this?