Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!twg.com!david
From: david@twg.com (David S. Herron)
Newsgroups: comp.windows.x
Subject: Re: more on XmString problem
Keywords: Motif 1.1, XmStringCreateLtoR, XmStringGetLtoR, UIL
Message-ID: <8861@gollum.twg.com>
Date: 25 Apr 91 17:39:35 GMT
References: <95655@lll-winken.LLNL.GOV>
Organization: The Wollongong Group, Palo Alto, CA
Lines: 39

In article <95655@lll-winken.LLNL.GOV> chapman@lll-crg.llnl.gov (Carol Chapman) writes:
>	  XtSetArg(al[ac],XmNlabelString,
>	   	 XmStringCreate("hello",XmSTRING_DEFAULT_CHARSET)); ac++;

This is a bad idea because it creates a memory leak.  XmStringCreate()
returns an XtMalloc()d object which is then duplicated into another XtMalloc()d
object inside the Motif library.  The one returned by XmStringCreate() is
then abandoned ..

	XmString string = XmStringCreate("hello",XmSTRING_DEFAULT_CHARSET);
	XtSetArg(al[ac],XmNlabelString, string); ac++;
		...XtSetValues()...
	XmStringFree(string);

Is much better.

>char* get_label(Widget         id)
	[num = 0;]
>  XtSetArg(wargs[num], XmNlabelString, &label_str); num++;
>  XtGetValues(id, wargs, num);
>
>  /* Pull the character string out of the XmString */
>  XmStringGetLtoR(label_str, XmSTRING_DEFAULT_CHARSET, &label);
>
>  /* Free string and make sure we free the pixmap (if there was one) */
>  XmStringFree(label_str);

Is exactly what my code does (though I use XmStringCreateLtoR())
and it just works.  Platforms: SysVr3.2.2/386 & Motif 1.0, SunOS 4.0.2
on Sun 386i with Motif 1.1.1, and SunOS 4.1.1 on Sun3 with Motif 1.1.1.


	David

-- 
<- David Herron, an MMDF & WIN/MHS guy, <david@twg.com>
<- Formerly: David Herron -- NonResident E-Mail Hack <david@ms.uky.edu>
<-
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