printf, data presentation

[Stuart Gathman]

The static screen presentation wheel has been invented many times over.
There are numerous packages available for purchase or free, many including
source code.  A useful discussion for the net might be what features
could/should be standardized.

The great thing about 'C', is that you can always roll your own.  We
did just that - it is not that big a project and includes pop up windows
and the works.  AT&T curses is so buggy, we had no choice but to
replace it.  The worst curses performance problem is that every character
requires a function call(s).  A low level display string function does 
wonders.  Our screen programs went from 100K with AT&T curses to
30K with BMS curses.  (NOTE, any PD curses is better than AT&T.)

We use a "screen painter"  to define data entry windows.  Dynamic windows
similar to the original posters are also used for things like multiple
choice lists.  Both approaches have advantages.

We have a verify function for each field defined in a table.  This allows
the same application to work in either a full duplex or block 
environment.  Only the field tab library module changes to accomodate.
In full duplex mode, the verify function is called immediately on field
exit.  In block mode, all are called on "ENTER".  This could be 
a run time choice with terminfo/cap extensions to support block mode.

My list of necessary features would include:

	1) both full duplex and block mode support.
	2) user definable formatting and verification.
	3) both painted and dynamic windows.
	4) independent windows
	5) table driven terminal configuration (terminfo,termcap)
	6) dynamic attribute control with good defaults
	7) both WP and DATA style fields
	13) IBM mode to disable type ahead :-)

A good book on the window level is "Ascii display programming in C".
-- 
Stuart D. Gathman	<stuart at bms-at.uucp>
			<..!{vrdxhq|daitc}!bms-at!stuart>