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From: mms@gpu.utcs.toronto.edu (John J. Chew III)
Date: Fri, 22-Jan-88 01:43:56 EST
Message-ID: <1988Jan22.014356.11779@gpu.utcs.toronto.edu>
Organization: The Poslfit Committee
Newsgroups: comp.sys.mac
Subject: Re: Sorting resources and a question about the list manager
References: <6577@jade.BERKELEY.EDU> <767@thorin.cs.unc.edu>
Reply-To: mms@gpu.utcs.UUCP (John J. Chew III)

In article <767@thorin.cs.unc.edu> steele@unc.UUCP (Oliver Steele) writes:
> jmm@thoth8.berkeley.edu () writes:
> >How do you sort resources?  I'm using the names of the individual resources
> >to fill a list, and I'd like to be able to sort the resources rather than
> >sort the list every time it gets created.  (The resource type is my own, and
> >I'd like to reorganize the order that the individual resources appear in
> >any way that I see fit, so I don't want to just sort by resource name.)
> The cheap trick here is to use AddResMenu() to add them all to the
> end of (empty) menu that you never draw (make one with NewMenu() and then
> dispose it after you're done with it), and read the names of the
> menu items from its data.  Write me if you need source.

A nicer way to sort things as you put them into a list is to use
the LSearch() function:

  /* for each cell you want to add */
  theCell.h=theCell.v=0;
  LSearch(dataPtr, dataLen, compareProc, &theCell, 1);
  LAddRow(1, theCell.v, 1);
  LSetCell(dataPtr, dataLen, theCell.1);

... where compareProc for a simple alpha sort would be:

pascal int compareProc(ap, bp, al, bl) Byte *ap, *bp; int al, bl; {
  return IUMagString(ap, bp, al, bl)<=0;
  }

However, to answer the original question of how to sort resources,
the best way is to sort them before you create them and to create
them in sorted order.  The second best way is to decide what order
they should be in, create a new resource fork and create copies of
them in sorted order there.  If you are determined to sort existing
copies of resources, read the caveat in IM IV-16 and then:

  - obtain handles to all the resources to be sorted
  - call RsrcMapEntry on each to get the resource reference offset
  - sort the resource references (12 bytes located at the
    above-obtained offsets from TopMapHndl, assuming your
    resources are in the most-recently opened resource fork,
    which they had better be)
  - call ChangedResource() on one of your resource handles.

jjc
-- 
john j. chew (v3.0)                       poslfit@gpu.utcs.toronto.edu
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