FVWM: ButtonPress, ButtonRelease propagation

[Lorinc Hever]

Hello,

I have question about ButtonPress, ButtonRelease release propagation.

FVWM version 2.5.1

We have a mouse and a trackball attached to our system. We have
applications interested in processing the trackball event in a special
way so it's interested in the ButtonPress and ButtonRelease events.

We found that in add_window.c fvwm unconditionally turns of the event
propagation of these events

attributes.do_not_propagate_mask = ButtonPressMask | ButtonReleaseMask;
XChangeWindowAttributes(dpy, FW_W(fw), valuemask, &attributes);

Could you help us what's the reason behind it? And what consequences
it might have if we remove this limitation?

Thanks a lot for your help!

Best regards,
Lorinc

[Thomas Adam]

Post by Lorinc Hever
Hello,
I have question about ButtonPress, ButtonRelease release propagation.
FVWM version 2.5.1

Get a newer version (2.6.1).

Post by Lorinc Hever
We have a mouse and a trackball attached to our system. We have
applications interested in processing the trackball event in a special
way so it's interested in the ButtonPress and ButtonRelease events.
We found that in add_window.c fvwm unconditionally turns of the event
propagation of these events
attributes.do_not_propagate_mask = ButtonPressMask | ButtonReleaseMask;
XChangeWindowAttributes(dpy, FW_W(fw), valuemask, &attributes);
Could you help us what's the reason behind it? And what consequences
it might have if we remove this limitation?

It comes from TWM, actually. I suppose it's there so that we don't pass a
button click to the window would if the window somehow disappears at this
point.

You'll need to be a lot more specific as to what it is you're trying to do.

-- Thomas Adam

[Thomas Adam]

Hi,

Post by Thomas Adam

Post by Lorinc Hever
Hello,
I have question about ButtonPress, ButtonRelease release propagation.
FVWM version 2.5.1

Get a newer version (2.6.1).

Post by Lorinc Hever
We have a mouse and a trackball attached to our system. We have
applications interested in processing the trackball event in a special
way so it's interested in the ButtonPress and ButtonRelease events.
We found that in add_window.c fvwm unconditionally turns of the event
propagation of these events
      attributes.do_not_propagate_mask = ButtonPressMask | ButtonReleaseMask;
      XChangeWindowAttributes(dpy, FW_W(fw), valuemask, &attributes);
Could you help us what's the reason behind it? And what consequences
it might have if we remove this limitation?

It comes from TWM, actually.  I suppose it's there so that we don't pass a
button click to the window would if the window somehow disappears at this
point.
You'll need to be a lot more specific as to what it is you're trying to do.

What became of this, if anything?

-- Thomas Adam