Input Parameters | Significance |
SEL_CHK_FNC fnc | pointer to check function |
Output Parameters | Significance |
none | - |
Return Code | Significance |
-1 | callback 0 pointer passed |
1 | callback function already entered |
0 | callback function added |
With the help of the check function you can decide, whether a button is to be entered into the button area. Several check functions can be put into a callback queue and be sequentially executed.
The check function must correspond to the specification int fnc(typ,idb,selnam,selusx,usxpar). The parameters are:
If the check function passed returns a Return Code = 0, checking will be continued in the queue. In case of Return Code different from 0 the queue will be left.