Re: xmosaic experience

Bill Janssen <janssen@parc.xerox.com>
Message-id: <0fXIpFoB0KGW4v0hoS@holmes.parc.xerox.com>
Date: 	Thu, 25 Feb 1993 14:50:57 PST
Sender: Bill Janssen <janssen@parc.xerox.com>
From: Bill Janssen <janssen@parc.xerox.com>
To: marca@ncsa.uiuc.edu (Marc Andreessen)
Subject: Re: xmosaic experience
Cc: WWW-TALK@nxoc01.cern.ch, ebina@ncsa.uiuc.edu
In-reply-to: <9302252239.AA21530@wintermute.ncsa.uiuc.edu>
References: <EfXGE90B0KGWQv0bZM@holmes.parc.xerox.com>
	<9302252239.AA21530@wintermute.ncsa.uiuc.edu>

Relax, Marc.  First off, I really like xmosaic, and am hoping version
1.0 will be really great!  But secondly, I'm not your customer.  Who
cares what I think?  Thirdly, it *is* a design decision, probably made
for all kinds of reasons I'm not aware of which make it a *good* design
decision.  Fourth, of course I read your explanation.

Excerpts from direct: 25-Feb-93 xmosaic experience Marc
Andreessen@ncsa.uiu (2331)

> The X Window System has this (to me, fatally flawed) design decision I
> hadn't suspected.  X windows can only be so big.  Up to the size of a
> 16-bit integer, in fact, in pixels.  This is really really bad.  This
> means that the other WWW X browsers (at least Viola and Midas, the
> only two I've been able to get working) will *not* correctly handle
> documents that, when layed out, take up more pixels in height than
> that -- e.g., your RFC.  Go try it on them.  Then look at what X
> Mosaic does, which is lay out as much text as possible in the window
> and then give you convenient automatic inlined hyperlinks to the
> remainder of the text, partitioned into window-sized chunks.  Then
> tell me who's making fatally flawed decisions.

Well, since you ask...  If you're displaying text, it really doesn't
matter what the maximum size of a window is, so long as you can get at
least one line on it, right?  As the user scrolls through the text, you
just show different lines, right?  But apparently what you're doing is
turning each document into a giant image of text, and then panning
through that image, which of course runs you into size problems.  This
is an OK idea if you're building something like HyperCard.  But WWW
isn't always like HyperCard, it tends to mix the ``holy scroller'' model
with the ``card shark'' model of hypertext.  So this approach isn't
really suited either to WWW or to the X Window System, so far as I can
see.  (The problem with it on X is that is uses big chunks of window
system resources, typically in one big burst that locks out everything
else on the screen!)  The ``correct'' approach would be more of what
Viola does, which is to use a text widget.  By the way, Viola, the only
other browser I use, *does* in fact use a text widget, and handles my
document just fine.

As I said above, maybe I'm missing something?

Bill