On Wed, 23 Aug 2006, at 22:36:35 (+0200), Joey Hess wrote:
> Marc-Jano Knopp wrote:
> > When running
> >
> > unclutter --help
> >
> > it displays, among other options:
> >
> > -visible ignore visibility events
> >
> > This option, however, is not documented in the manpage, and is not
> > self-explanatory for someone not familiar with X11 internals.
>
> Such as myself. :-)
Oh. :-)
As far as I (also not familiar with X11 internals) understood, the X11
server sends a notification to unclutter's transparent 1x1 subwindow
under the invisible cursor (so this doesn't apply if "unclutter -grab"
is used), if the window's visibility changed state (which can be
VisibilityUnobscured, VisibilityPartiallyObscured, and
VisibilityFullyObscured).
Usually, InputOnly windows (which the unclutter window is created as,
since it doesn't need to display anything) should not get
VisibilityEvents at all:
,----[ Xlib - C Language X Interface: 10.10.10. VisibilityNotify Events ]---
|
| However, this event is never generated for windows whose class
| is InputOnly.
|
`----[ /usr/share/X11/doc/hardcopy/X11/xlib.PS.gz, package "xspecs" ]---
But despite this class, some servers generate this event when the
subwindow is mapped, and report varying visibility states. For these
servers, you have to use "-visible", as otherwise the cursor would never
be hidden, since its subwindow would immediately be destroyed due to the
VisibilityNotify event.
Why the authors don't simply always ignore visibility events is
beyond me. I couldn't think of any situation where evaluation of the
visibility state would be useful, but as I said: IANAXE (I am not an X11
expert) and have never written a program using Xlib. All of the above I
inferred from both the Xlib manual and the unclutter source
code. I might suffer from dyslexia or ADS, and I can't code anyway, so
better check twice.
> If you know what it does, I'll document it on the man page.
For now, you could write
-visible Ignore visibility events (does not apply to -grab).
If the cursor never gets hidden, despite a generous
-jitter value, try this option.
to the manpage. No liability assumed, though, I could be totally wrong.
And while you're at it, you could fix the various typos in the help
text (dont -> don't etc.). :-)
Gruß
Marc-Jano
