Re: subfile SFLFOLD/SFLDROP and cursor positioning

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

> I was using both SFLDROP and SFLFOLD on F14 and 21/N21.
> I took F14 out of the RPG code as Folding & Unfolding apparently never goes
> back to the program anyway.
> Then I took out the SFLDROP line of code in the DDS, and the program still
> folds and unfolds as I want.  I was surprised I didn't need both SFLDROP &
> SFLFOLD, and that I didn't have to code for *in21 in the RPG, except to eval
> *in21 = MODE after the exfmt.

That's true.  The *IN21 is only used when the PROGRAM (rather than the 
user) wants to control whether the screen is in fold or drop mode.

For example, I've written programs where there's no space for an error 
message in the subfile.  So I put the error message on the next line 
(using SFLFOLD).  When an error occurs, my program automatically turns 
FOLD mode on so that the user will see the error message.  If there are no 
errors, it uses SFLDROP so that the error message field isn't displayed.


> Firstly, I would like the cursor to remain on the same subfile record when
> the screen flips.  For instance, if the cursor is on subfile record 3(line 9
> 10, or 11 of the subfile screen on the unfolded screen I would like to
> press F14 to have the folded view, and have the cursor move up to line three
> of the subfile screen record.

Hmmm... it surprises me that this isn't the default behavior?  If it's not 
the default behavior, there's not much you can do about it. As you've 
already discovered, control isn't returned to your program when the "fold" 
f-key is pressed, so you can't insert logic to handle it.


> In the opposite direction I would like the same to occur, and in 
> addition, show the section of the subfile that has the cursor if the 
> cursor happened to be on record 5 through 12 of the subfile screen.

Same issue.


> Secondly, I would like to be able to get the information about the first
> record presently being displayed on the screen, regardless of the location
> of the cursor.

You can't get information about the first record on the screen because 
control isn't returned to your program.

What you may need to do is set SFLFOLD/SFLDROP to a *different* function 
key than F14.  For example, maybe set it to F24, and then don't TELL 
anyone that SFLFOLD/SFLDROP are F24 so that the user never presses it.

Then, set up F14 with CF14.  When control returns to your program because 
F14 is pressed, you can get the top RRN of the subfile from the INFDS, you 
can use SFLCSRRRN to get the actual record that the cursor was on. You can 
use SFLRCDNBR to move the cursor, and you can use *IN21 to switch between 
fold and drop.

This way, your program DOES have control and it can do whatever it needs 
to.

Unfortunately, it's a hack, because F24 is still available to do 
drop/fold, and you have to hide it from the user so that he uses F14 
instead.

Hope that makes sense.