gates@IPSUN.LARC.NASA.GOV (Ray Gates) (11/22/89)
HELP!!!!
I am having problems with callbacks. I have a commandWidget that has two
callback routines. One of these routines enables a popup. Based on an error
condition in my program, I want to remove the enabling of the popup from the
callback list. I tried using XtRemoveCallback but it seems to "miss" the first
time around and still pops up the popup. What am I doing wrong??? What
alternatives (if any) do I have?? I know this probably doesn't make a lot
of sense but what does these days (editorial comment)?? Thanks in advance.
_______________________________________________________________________________
"Mama, mama, many worlds | Ray Gates
have come since I first | CSC/NASA-Langley
left home." | gates@ipsun.larc.nasa.gov
| 804.865.1725
-------------------------------------------------------------------------------
DISCLAIMER: The comments/opinions contained within are my own and do not
necessarily represent the opinions of my employer(s).
-------------------------------------------------------------------------------gates@CSCSUN1.LARC.NASA.GOV (Ray Gates) (12/15/89)
Forgive me if this has been posted previously. Having problems with my
black hole mailer.
HELP!!!!
I am having problems with callbacks. I have a commandWidget that has two
callback routines. One of these routines enables a popup. Based on an error
condition in my program, I want to remove the enabling of the popup from the
callback list. I tried using XtRemoveCallback but it seems to "miss" the first
time around and still pops up the popup. What am I doing wrong??? What
alternatives (if any) do I have?? I know this probably doesn't make a lot
of sense but what does these days (editorial comment)?? Thanks in advance.
_______________________________________________________________________________
"Mama, mama, many worlds | Ray Gates
have come since I first | CSC/NASA-Langley
left home." | gates@ipsun.larc.nasa.gov
| 804.865.1725
------------------------------------------------------------------------------swick@ATHENA.MIT.EDU (Ralph R. Swick) (12/15/89)
> I am having problems with callbacks. I have a commandWidget that has two > callback routines. One of these routines enables a popup. Based on an error > condition in my program, I want to remove the enabling of the popup from the > callback list. I tried using XtRemoveCallback but it seems to "miss" the first > time around and still pops up the popup. You're not, by any chance, calling XtRemoveCallback from a callback that's on the list you're trying to change, are you? There is special code to make sure that any changes to a callback list do not affect an in-progress evaluation of that list, producing exactly the symptoms you describe. Since there is no explicit ordering of invocation of the callbacks on a list, you could never rely upon an "earlier" callback being able to disable a "later" one by removing it from the list anyway.