Crawling info displays and slide shows

ira@linus.mitre.org
Date: Thu, 30 Sep 93 15:32:20 -0400
From: ira@linus.mitre.org
Message-id: <9309301932.AA03065@ellington.mitre.org>
To: marca@ncsa.uiuc.edu
Cc: www-talk@nxoc01.cern.ch
In-reply-to: Vinay Kumar's message of Thu, 30 Sep 93 10:00:25 PDT <9309301700.AA00652@eit.COM>
Subject: Crawling info displays and slide shows 
Reply-To: ira@mitre.org


I've just subscribed to this newsgroup so excuse me if this
information is somewhat redundant to the discussion of slide shows in progress.

The MITRE Corporation recently modified XMOSAIC to do slide shows.
The approach was to modify the html parser to pick out new tokens
which specified the desired events which are loaded into an event
queue and which is then executed. The following is the specification
for the limited set of possible events, where the file names could be
any URL. If there is any interest in taking our modifications for
incorporation in NCSA's XMOSAIC, please contact me.


A "playmode" HTML document consists of a sequence of tags, as defined
below.  Each tag begins with "<" and ends with ">".  Tag keywords
(e.g. XV) are case-INsensitive, but pathnames are case-sensitive.
Parse errors will be noted (using stderr or maybe a logfile) but will
not result in any value being placed in the FIFO.

Pathnames are not quoted.  Pathnames may not contain blanks, cross
document line boundaries, or contain the character ">".


<PLAYMODE> Begin "playmode" mode.  This mode continues to the end
		of the document.



<SCREENFMT #>	Display a predefined window, widget, whatever,
	        onscreen.  Each predefined window has a number "#".
	        Since there could be any value for "#", it is not
	        range-checked.
		NOTE: # may be an actual numeric value or a symbolic
		representation (ex: PICW)

PICW 1      /* image window only */
#define PICWINPUT 2 /* image window with query input box underneath */
#define PICWTXTW 3  /* simplified mosaic and image windows side-by-side */
#define TXTW 4      /* only the normal "simplified" mosaic window */


<PAUSE #>       Enter a timing loop and wait # seconds before dequeuing 
                the next event.


<XV pathname caption>
       		Invoke the program "xv" with argument "pathname".
	        Pathname should denote a file which "xv" can display.
		Caption is a string to be displayed underneath the image
		when present.

<MPGPLAY pathname>

		Invoke the program "mpeg_play" with argument
		"pathname".

<QTPLAY pathname>

		Invoke the program "quicktime" with argument
		"pathname".


<PLAYAUDIO pathname>

	        Invoke a program to "play" the audio data in the
	        file denoted by "pathname".

<XMQUERY  "string">

		Accept input from the keyboard and act according
		to the value. 

<LOAD_DOC pathname>

		Cause XMosaic to load the file denoted by
		"pathname" and display it.  Note that "pathname"
		must be a legal HTML file for this to work
		correctly, and that this scanner won't check it
		for legality.