Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!uw-june!uw-entropy!bill
From: bill@entropy.ms.washington.edu (Bill Dunlap)
Newsgroups: comp.windows.x
Subject: chaining resource converters
Message-ID: <1057@entropy.ms.washington.edu>
Date: 13 Nov 88 20:31:15 GMT
Reply-To: bill@elk.stat.washington.edu (Bill Dunlap)
Distribution: na
Organization: UW MathStat, Seattle
Lines: 18

I would like to write a resource converter to convert a String to
a ColormapSegment.   The String will be a list of color names.  It
seems reasonable to run through the list of color names and pass
each to CvtStringToPixel.  However, that is static to lib/Xt/Converters.c.
If I use XtConvert I must supply a widget but I have no widget to
supply when I register the converter (while in ClassInitialize()).
If I use XtDirectConvert I need access to CvtStringToPixel.
What is the best way to do this?

A side issue concerns allocating space for the ColormapSegment.  Its
length is unknown at compile time so I must XtMalloc() space for it.
Is there a conventional way to tell a widget that it must free space
allocated by a resource converter or for the widget to tell the
conversion mechanism that it is done with a resource?

Bill Dunlap
Dept. of Statistics, U. of Washington, Seattle
bill@elk.stat.washington.edu