Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcsun!unido!ztivax!tumuc!guug!fidelio
From: fidelio@guug.UUCP (Michelle Nelson)
Newsgroups: comp.windows.x
Subject: Defining Callbacks from resource files
Keywords: Callbacks Type Conversion
Message-ID: <38@guug.UUCP>
Date: 18 Dec 89 19:04:02 GMT
Sender: root@guug.UUCP
Organization: GUUG e.V., Munich, W. Germany
Lines: 27


Hello.
I am having a problem setting up callback functions from a resource file.
I would like to be able to choose which function is called from a particular
menu item at run time and not compile it into the program. The error which
I get when trying to use the following resource file definition

Fbmenu*menu_item1*select:	(* purchasing)()
	or this resource file definition
Fbmenu*menu_item1*select:	purchasing
is:
X Toolkit Warning: No type converter registered for 'String' to 'Callback'
conversion.

I know that the select resource wants a pointer to a function 
and that this is a string.
There doesn't seem to be a converter from string to pointer...
I am using the hp widgets and toolkit.
Please let me know if you have any suggestions.  (i.e. if I am being
unreasonable about defining callbacks at runtime...)  I am a relative
newcomer to X windows programming. 

(e-mail would be greately appreciated as I am worried I would miss
the response on the newsgroup.)


Michelle Nelson