x"AF" Function 57 - Enable or Disable Delayed DISPLAY

Updates the screen with several DISPLAY statements using only one call.

The x"AF" function 57 allows you to execute several DISPLAY statements without updating the screen each time one is executed. You then execute only one call to update the screen with all of them, often resulting in a faster updating process.

Screen updates are delayed until you either execute an ACCEPT statement or use this call to update the screen and re-enable screen updating (see below).

Syntax:

call x"AF" using   control-update-fn
                   control-update-param

Parameters:

`control-update-fn`	pic x comp-x value 57.
`control-update-param`	pic x comp-x value field containing one of the following values: 1 - use the delayed update method 0 - disable the delayed update method, causing the screen to be immediately updated

Comments:

The result of executing an ACCEPT statement is the same as executing this call with parameter set to 0. Therefore, after you execute an ACCEPT statement, you must execute another call to this function with parameter set to 1 if you still want to use the delayed update method.

Example:

 01 control-update-fn       pic x comp-x value 57.
 01 control-update-param    pic x comp-x.
   ...
     move 1 to control-update-param.
     call x"af" using control-update-fn
                      control-update-param.
            ...
* Any DISPLAY statements here are not reflected on the screen
      ...
     move 0 to control-update-param.
     call x"af" using control-update-fn
                           control-update-param.
* Now all the previous displayed information is visible.