Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!kimba!hvr
From: hvr@kimba.Sun.COM (Heather Rose)
Newsgroups: comp.windows.x
Subject: Re: Widget Client data (info request)
Message-ID: <132264@sun.Eng.Sun.COM>
Date: 27 Feb 90 02:47:14 GMT
References: <8395@shlump.nac.dec.com>
Sender: news@sun.Eng.Sun.COM
Reply-To: hvr@sun.UUCP (Heather Rose)
Organization: Sun Microsystems, Mountain View
Lines: 40

In article <8395@shlump.nac.dec.com> nick@deccan.dec.com (Nick Tsivranidis) writes:
>
>	I was under the impression that one could associate a client data
>field with a widget (ala Suntools). Is there such a thing?  Client data
>is a piece of application data (normally a memory address) that one can
>associate with a widget. This provides for a convenient mapping between
>Widget space and Application space. Thanx in advance.

XView provides this (as did SunView).  Here's a summary of how it works at
the end of this message.  

Regards,

Heather

----------------------------

int INSTANCE;

main(){
	Data data;

	data = (Data)malloc(DataSize);
	...
	INSTANCE = xv_unique_key();
	...
	obj = xv_create(owner, OBJ_TYPE,
		...
		XV_KEY_DATA, INSTANCE, data,
		...
		NULL);
	...
	xv_main_loop(frame);
}

callback_proc(obj, ...) 
	...
	data = (Data) xv_get(obj, XV_KEY_DATA, INSTANCE, NULL);
	...
}