Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!ut-emx!walt.cc.utexas.edu!bittner
From: bittner@walt.cc.utexas.edu (George A. Bittner)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Mutual Exclude Gadgets
Summary: The Guru speaks
Message-ID: <23148@ut-emx.UUCP>
Date: 13 Jan 90 01:04:46 GMT
References: <3454@hub.UUCP>
Sender: news@ut-emx.UUCP
Reply-To: hcobb@walt.cc.utexas.edu (Henry J Cobb)
Organization: The University of Texas at Austin, Austin, Texas
Lines: 25


	Here's how to do it.  I hope that C= will code this for us.

AllocGroup();
	returns a 32bit magic cookie  used internally to track groups.
You just use this pointer to add gadgets to groups.  Returns NULL when 
out of space.

AddToGroup(GadgetA , GroupB);
	Adds A to the group.  Only one gadget in B can be active at a time.

RemoveFromGroup(GadgetA, GroupB);
	A no longer excludes the gadgets in B, unless it is in another Group
with them.

DelleteGroup(GroupB);
	Returns the adminstrative space used to handle B.

	Internally the functions keep a list of who's in each group and only
munge the gadgets that conflict, so searching takes no extra time.  If I was
going to do this as an add-on I would position my program high up in the 
input stream and produce gadget deselections that I trap after Intuition has
finished with them.

	Henry J Cobb 	hcobb@ccwf.cc.utexas.edu