xmosaic experience

Marc Andreessen (marca@ncsa.uiuc.edu)
Thu, 25 Feb 93 14:39:58 -0800

Bill Janssen writes:
> I had an unsettling experience last night. I wanted to look at the
> latest draft of an Internet RFC, and thought to myself, ``Why not
> use this nifty xmosaic tool to fetch it?'', since I had recently
> discovered xmosaic. So I typed in a URL, and it core-dumped on me.
> Well, it's only version 0.8, and probably doesn't know everything
> yet, so I tried going through a gopher gateway (still using xmosaic)
> and accessing it that way. Well, I got through to the RFC -- and
> suddenly my X server started chewing up CPU. After chugging for
> several minutes (X11R5 on a Sparc-2 with 48MB of RAM), xmosaic puts
> up the text of the RFC, marked ``page 1 of 5''. Huh? Surely this
> document has about 50 pages?
> Turns out xmosaic has this (to me, fatally flawed) design decision I
> hadn't suspected. Instead of using a text widget (I'm not familiar
> with the capabilities of the Motif text widget, but perhaps it does
> not handle multi-font, multi-color text), xmosaic seems to *paint*
> text strings on a window, and then pan the window around when the
> user scrolls, rather than re-drawing the text.

You are correct that the Motif text widget does *not* handle
multi-font, multi-color text.

Did you read the explanation for the "document pages" feature (or
fatally flawed design decision, whichever) in the docs, for which a
hyperlink is especially set up right by where it says "Document Page 1
of 5"? Apparently not. Let me summarize.

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.


Marc Andreessen
Software Development Group
National Center for Supercomputing Applications