Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ico!auto-trol!marbru
From: marbru@auto-trol.UUCP (Martin Brunecky)
Newsgroups: comp.windows.x.motif
Subject: Re: Motif Text Widget Performance Problems
Message-ID: <880@auto-trol.UUCP>
Date: 12 Oct 90 16:52:10 GMT
References: <9873@bunny.GTE.COM>
Reply-To: marbru@auto-trol.UUCP (Martin Brunecky)
Organization: Auto-trol Technology, Denver
Lines: 68

In article <9873@bunny.GTE.COM> dcr0@bunny.GTE.COM (David Robbins) writes:
>I have been given a small task: find a way to improve certain aspects of
>the Motif 1.0 text widget.  I am relatively new to Motif, and may have
>missed some relevant discussion in this newsgroup, so bear with me.  I am
>
>A) Have any of you encountered and solved performance problems with the
>   text widget?  If so, please share what you can with me and the net.

    I had not only performance problems, but primarilly functionality
    problems. Things that were supposed to work and did not, and things
    that we needed but aren't there (overstrike mode, smooth scrolling
    -- oh, there's a lot to be said about scrolling, source limited
    to memory buffer only etc...). As we had a text widget based on Xaw
    R3 widget, we'w gradually evolved it ... so today I don't see any
    reason to go back and use Motif's one, based on archaic architecture
    from R2 intrinsics.
>
>B) Am I completely off the wall in thinking that I understand the problem?
>
    Mhm. A don't think you are completely off the wall, but I am not
    sure you understand the magnitude of the problem. When I took over
    our text widget, I estimated 2 weeks to finish it. It took me 3+ month,
    and though I dropped the code from over 10,000 lines down to 5,000 lines,
    it was quite a frustrating period.

>C) To what extent does Motif 1.1 solve these and perhaps other performance
>   problems, particularly for the text widget?  (I do not have 1.1, nor do
>   I expect to see it soon -- but if it answers my prayers, I may be able
>   to acquire it.)

    Several people claimed significant DEGRADATION in 1.1 (I haven't received
    1.1 yet [thanks, OSF-)] ). Primarilly caused by additional functionality,
    such as noncontiguous selection ranges (wrong term, I guess-).
>
>D) Are the Motif developers aware of these problems?
>
    I am not quite sure if Motif developers watch this newsgroup. From the
    postings on Motif talk list, I estimate OSF has about 3 SQA people, 
    about 2 engineers and the God knows how many managers -).
    I believe that the only think CONSIDERED by OSF are BUGREPORTS. Any
    suggestions here or on the motif-talk list are just whining.
>
>

    One thing that is necessary, really necessary, is a vastly simplified
    text field. I'v been told that Motif 1.1 will have a text field gadget,]
    but I haven't heard about it yet.
    In fact, I don't think that a gadget is a good thing here, since in absence
    of a window you have to put clip rects into GC, either having a private
    GC (much more expensive than a simple window), or you have to constantly
    load/remove clip rects - lots of overhead again.
    Such a text field would have much smaller instance, as the "big" items such
    as line table and lots of the scrolling support can be nuked out. It
    may share the same sink/source objects with the "big brother", as those
    (if correctly implemented) may have fairly small instances.

    The tough task is how to inherit what's good in the "big" Text widget, so
    that the Motif's typical code duplication is avoided.

    [Few weeks ago I offered OSF to mail them the code for my text widgets
    hierarchy, just to look at different optimizing techniques used, but
    nothing came back. They probably know better.]

-- 
=*= Opinions presented here are solely of my own and not those of Auto-trol =*=
Martin Brunecky                   marbru@auto-trol.COM
(303) 252-2499                    {...}ncar!ico!auto-trol!marbru
Auto-trol Technology Corp. 12500 North Washington St., Denver, CO 80241-2404