Embedded Procedures

Embedded Procedures have been implemented to make programming even simpler. It is a way to attach a procedure, a paragraph or a section, to one or more screen section entries and have them activated before the control activation, after the control activation and when a function key is pressed.

Every Screen Section item, no matter if it is a group or a single control, can handle up to three different Embedded Procedures. If an Embedded Procedure is assigned to a group, it is inherited by all the groups or controls that it contains, unless they have their own embedded procedure set.

Before executing any Embedded Procedure, the following data items, defined in "iscrt.def" are updated:

01  screen-control is special-names screen control.     03  accept-control                           pic 9.     03  control-value                            pic 999.     03  control-handle                           handle.     03  control-id                               pic xx comp-x.

accept-control	Always set to zero.
control-value	Set to the index of the control. That index is a progressive number that starts at 1 and is increased by one for each control that can be activated. Display-only controls (such as Labels) do not cause the number to increase.
control-handle	The handle of the control that caused the Embedded Procedure to be executed.
control-id	The ID of the control that caused the Embedded Procedure to be executed. The ID of the control is the value of the ID Property. If not explicitly set, a progressive number is assigned. Display-only controls (such as Labels) cause the number to increase.

After the last statement of an Embedded Procedure has been executed, the value of accept-control is evaluated and the program behaves as explained below. This means that the programmer can influence the program behavior changing the value of accept-control.

Value	Behavior
0	The program behavior is not changed, this is the default.
1	The control that has the same index set in control-value is activated.
2	The ACCEPT Statement terminates and the termination value set in control-value is assigned to the special register CRT STATUS.
3	The ACCEPT Statement terminates and the exception value set in control-value is assigned to the special register CRT STATUS. This is the most common way to simulate that a Function key has been pressed.
4	The control that has the same ID set in control-id is activated. If controls have the same ID, one of them is activated arbitrarily. Assigning the same ID to several controls is deprecated. If the control with the same ID is either protected, not visible or not enabled, then the cursor is moved on the next available field.