Re: SUBFTR01 and SUBFTR02 - OVERLAY vs CLRL and inserting blanks

["Frances Denoncourt" <Frances.Denoncourt@xxxxxxxxxxxxxxxxx>]

Simon, Booth, Stephen, Terry,
Thanks for making me stop and think this through. Following is what
worked for me:

What ended up working for me * TR097MDR
WRITE     MSGSUBC                
WRITE     SUBFTR01               
EXFMT     SUBCTL01               
 
WRITE     MSGSUBC                
WRITE     SUBFTR02               
EXFMT     SCREEN02               
 
 
A          R SUBCTL01                  SFLCTL(SUBFIL01)                

A                                      OVERLAY                         

 
A          R SUBFTR01                                           
A***************************           CLRL(*NO)                
A                                      OVERLAY                  
A                                      ERASE(SUBFTR02)
A*****************************    23  3'                               
  - 
A****************************                                          
  - 
A*************************                    '                        
              
 
A          R SCREEN02                                          
A                                      OVERLAY                         
       
 
A          R SUBFTR02                                          
A*******************************       CLRL(*NO)               
A                                      OVERLAY                 
A                                      ERASE(SUBFTR01)         
A*************                    23  3'                               
  -   
A***************                                                       
  -   
A***************                              '                        
      
A**************                   23  3'          '                    
      
                
Fran Denoncourt
Sr. Programmer/Analyst
Pinal County Treasurer's Office
Florence, AZ 85232
(520) 866-6404
Frances.Denoncourt@xxxxxxxxxxxxxxxxx 
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> > > Simon Coulter <shc@xxxxxxxxxxxxxxxxx> 09/07/2008 1:39 AM >>>

On 06/09/2008, at 3:27 AM, Frances Denoncourt wrote:

> My other issue is that the first footer is still displaying in  
> places along with the second.

Then the screen area occupied by the first footer is not being  
cleared when the second footer is displayed. This is termed "bleed- 
through". It's usually caused by PUTOVR plus OVRATR and/or OVRDTA or  
CLRL(*NO)

OVERLAY is used to build a single screen from multiple record  
formats. The default behaviour is to clear the screen for each record 

format written. If you want multiple formats on the display you  
generally use OVERLAY. Each record format must NOT share any screen  
space with other active record formats. If a format with OVERLAY  
specified is written to the display AND it shares even one character  
position with another record format already on the display the record 

format already displayed is erased. Record formats that share screen  
space do not OVERLAY they OVERLAP.

If you need to OVERLAP record formats then the OVERLAY will not help. 

You must use CLRL(*NO) to stop the OS from erasing the overlapped  
record format, or you must use PUTOVR plus OVRATR and/or OVRDTA to  
send new attributes and/or data to the existing display. This  
technique leads to bleed-through because the OS does not clear the  
screen area before displaying the new information. Your application  
must ensure bleed-through cannot occur. The usual technique for that  
is to code blank constants in all the unused parts of the overlapping 

record format.

> There is some code in there placing blanks in the line before the  
> footer info.

This is probably to hide data from previous record formats that  
bleeds through when new information is displayed.

> I put some identifying remarks in its place and could see what was  
> still showing from one footer to the other.
>
> Maybe I should just write blanks to cover up the entire first  
> footer (or another blank footer) then write the second.

You could do that. Or you could instruct the OS to ERASE an existing  
format when writing another footer. WRITE FOOTER2 and ERASE FOOTER1  
at the same time. See the DDS keyword ERASE.

> There is one of your old posts that might help out, but I'm not  
> sure about the comment about reordering the write of records to the 

> display device.

This just means that most people think you have to build a screen  
from the top down. For example:
WRITE HEADERcauses display to be cleared
WRITE BODYwith OVERLAY
WRITE FOOTERwith OVERLAY
but you can do it in any order that makes sense to your code. For  
example:
WRITE BODYcauses display to be cleared
WRITE FOOTERwith OVERLAY
WRITE HEADERwith OVERLAY

What I was getting at in the append you referenced was simply that  
the programmer may need alter the order in which record formats are  
written to ensure the screen is cleared properly with the first WRITE 

and then the other formats OVERLAY properly.

> Which would be the best way to code for this?

Depends on your existing DDS and HLL code. Proper understanding of  
DDS will help and avoid all the "try this" and "maybe that" answers  
you've been getting.

Regards,
Simon Coulter.
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