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Re: Group leader

Imanol Echave (ccaeccai@sc.ehu.es) writes:

> 	I have a little question: What is the difference between the GROUP_LEADER
> keyword on XMANAGER and the same keyword used on a top-level base? Do they work
> on the same way?

In this case it doesn't matter at all whether you assign
the group leader to the top-level base with the GROUP_LEADER
keyword when you create the TLB or when you call XMANAGER,
but this is not always the case with the TLB. For example,
you should never use the EVENT_PRO keyword to assign the
event procedure to a TLB; always use the EVENT_HANDLER
keyword on XMANAGER. Similarly, you should never use the
KILL_NOTIFY keyword to assign a clean-up routine to the
TLB; always use the CLEANUP keyword on XMANAGER.

Failure to heed these warnings causes some VERY strange
behaviour in widget programs. And the warnings in the
documentation are worded in such a way that many people 
miss them. :-)



David Fanning, Ph.D.
Fanning Software Consulting
E-Mail: davidf@dfanning.com
Phone: 970-221-0438, Toll-Free Book Orders: 1-888-461-0155
Coyote's Guide to IDL Programming: http://www.dfanning.com/