Kbase P14889: How to implement a timer without an OCX
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/05/2011 |
|
Status: Verified
GOAL:
How to implement a timer without an OCX.
GOAL:
How to implement a timer portable across Windows and UNIX.
FACT(s) (Environment):
Progress 9.x
OpenEdge 10.x
All Supported Operating Systems
FIX:
The idea is to have a window with one fill-in widget to serve as the clock. It is advisable to make this fill-in VIEW-AS TEXT (by making sure it is displayed but not enabled for user input.)
One other feature is a logical variable called GET-OUT which serves as a way for the program to get out of the timer loop and exit the program. Define it as follows, with initial value FALSE:
DEFINE VARIABLE get-out AS LOGICAL INITIAL FALSE.
To implement the timer, write a loop around the WAIT-FOR that is similar to the following:
DO WHILE TRUE:
fill-in-1:SCREEN-VALUE = STRING(TIME, "HH:MM:SS").
WAIT-FOR U1 OF CURRENT-WINDOW PAUSE 1.
IF get-out THEN LEAVE.
END.
The way to "break out" of the loop is to set get-out to be true.
One event to take into account with this is WINDOW-CLOSE, since as it stands the WAIT-FOR above is waiting for a "dummy" programmer event, U1, and not the usual WINDOW-CLOSE. So, in order to assure that WINDOW-CLOSE will work properly, you need to make sure a trigger is defined for the WINDOW-CLOSE event:
ON WINDOW-CLOSE OF WINDOW-1 DO:
get-out = TRUE.
RETURN NO-APPLY.
END.
The RETURN NO-APPLY assures that a beep won't occur when the user closes the window using a ventilator.
One other way that the logical variable get-out could be set is as the result of an "Exit" button:
ON "CHOOSE" OF btn_exit DO:
get-out = TRUE.
END.
Other events can set get-out = TRUE as desired.