Legacy Document

Inside Macintosh: Networking /

Chapter 10 - Link-Access Protocol (LAP) Manager / LAP Manager Reference

Routines / Notifying Routines When Your Application-Defined Transition Occurs

ATPreFlightEvent

The ATPreFlightEvent function calls the routines specified by each of the entries in the AppleTalk Transition Queue with notification of a transition event that you have defined and allows each routine in the AppleTalk Transition Queue to return a result code and other information to your calling routine.

FUNCTION ATPreFlightEvent (event,cancel: LongInt;
                           infoPtr: Ptr): OSErr;

event

The AppleTalk transition event code for the initial transition about which you want to notify the AppleTalk Transition Queue event routines. This code can be any four-character string that starts with an uppercase letter--that is, any value in the range $41 00 00 00 through $5A FF FF FF.

cancel

The AppleTalk transition event code for the transition that notifies
the AppleTalk Transition Queue event routines that your original transition notification is canceled. This code can be any four-character string that starts with an uppercase letter--that is, any value in the
range $41 00 00 00 through $5A FF FF FF.

infoPtr

A pointer to information that you make available to the AppleTalk Transition Queue entry routines. If you do not want to pass any information to these routines, set the infoPtr parameter to NIL.

DESCRIPTION

The ATPreFlightEvent function calls all of the routines in the AppleTalk Transition Queue with the AppleTalk transition event code you specify in the event parameter. If any routine in the AppleTalk Transition Queue returns a nonzero function result, the ATPreFlightEvent function calls each of the routines that it has already called, this time with the AppleTalk transition event code you specify in the cancel parameter.

SPECIAL CONSIDERATIONS

You can call the ATPreFlightEvent function only at virtual-memory safe time.

AppleTalk transitions defined by developers might return other result codes.

RESULT CODES

noErr

0

No error, or unrecognized event code

SEE ALSO

See Inside Macintosh: Memory for information on virtual memory.

For information about developer-defined transition events, see "Developer-Defined Transitions" on page 10-21 and "Defining Your Own AppleTalk Transition" on page 10-21.