Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!pcrat!rick
From: rick@pcrat.uucp (Rick Richardson)
Newsgroups: comp.windows.x
Subject: Incremental Display of Widget Tree
Message-ID: <1990Aug8.025339.3419@pcrat.uucp>
Date: 8 Aug 90 02:53:39 GMT
Organization: PC Research, Inc.
Lines: 68

I want to create a Box (or RowColumn in Motif) widget that contains
a bunch of Command (or PushButton in Motif) widgets.  But with a
twist.

The labels on the buttons themselves take anywhere from 1-3 seconds
apiece to compute, and are information that the user can read in
and of themselves.  The buttons represent pages of a document.

As each button widget is created, I'd like to process events
ala XtMainLoop, but only until I'm sure the newly created button
has been displayed.  Once the button is displayed, I need
to continue parsing an input file until the next button is
ready to be added and displayed.

I want to do this displaying as each button is created so that
the user has something to look at and think about rather than
a dumb hourglass or Please Wait message.

I've scoped out the pseudo code, as indicated below, but
there are a few things I haven't figured out how to do,
marked by ***'s.

Does anybody have any ideas or pointers on how I can accomplish
this?  Is there some event I have to wait for that says that
everything created so far has been displayed?  What is it?

main	# main program
{
	- box = XtCreateManagedWidget( ...Box..., toplevel, ... )
	  (and other widgets)

	- XtRealizeWidget(toplevel)

	- Now, process events until widgets are displayed
	  **** How do I do this ****

	- call parse(document)

	- call regular XtMainLoop()
}

parse_ready	# called from "parse", usually many times
{
	- button[n++] = XtCreateManagedWidget( ...Command..., box, ... )
          The 'label' on this button is information in itself.

	- XtRealizeWidget(button[n++])
	  *** is this correct? ***

	- Now, process events until this new button has been fully
	  displayed.
	  *** how do I do this ***

	- return back to parse();
}

parse
{
	While there are more pages to process
	{
		- format the page (somewhat CPU intensive)
		- call parse_ready
	}
}

-Rick
-- 
Rick Richardson - PC Research, Inc., uunet!pcrat!rick, (201) 389-8963