Re: clearing a screen in ada? (new to ada)

[Ade Vickers <nospam@ttoolsbase.com>]

"Marin D. Condic" wrote:
> 
> Nigel wrote:
> >
> > ahhh sorry I am using GNAT on a PC using the ADAGIDE, we basically are only
> > allowed to use the standard libs/packages that come with gnat, and I was
> > hoping to find infor for moving the cursor round the screen such as using a
> > comand like CLS to clear the screen and also the LOCATE type commands for
> > postioning the cursor, I have tried using set_col and set_line in the
> > Text_IO package, but it only works in a positive manner and so I can't go
> > back up the screen. basically I am righting a box prog to make my input
> > screens look a little more interesting, and not being able to move the
> > cursor back up the screen when I have drawn the box is making this hell
> > thanks once again for help :o)
> 
> You could "roll your own" screen control code. All you have to do is
> send the proper escape sequences to the terminal and you can get it to
> clear the screen, position the cursor, etc. You can send the escape
> sequences using Ada.Text_IO facilities, so there isn't anything
> non-standard about it. You can probably get by if you build a small
> package with two procedures: Clear_Screen and Goto_XY. Just get the
> escape sequences for those two features and wrap a little code around
> the Goto_XY one to convert its parameters to proper screen coordinates.

The distribution of GNAT I downloaded the other day contains (in the
Examples directory) a file to do just this: screen.ads/.adb.
 
> Anybody remember off the top of their head what the escape codes are for
> those functions?

ESC[2J - clear screen
ESC[yy;xxf - move to row yy, col xx

That's contained within screen.adb; my memory would never have stretched
to remembering those...

-- 
Cheers,
Ade.

If at first you fail, cheat. Repeat until caught, then lie.