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Chapter 2 - Event Manager / Event Manager Reference

Data Structures

The High-Level Event Message Record

You can search your application's high-level event queue for a specific high-level event by using the GetSpecificHighLevelEvent function and providing a filter function. Your filter function receives a pointer to a high-level event message record that contains information about a high-level event. (See "Filter Function for Searching the High-Level Event Queue" on page 2-114 for information on how to define a filter function.)

The HighLevelEventMsg data type defines the structure of a high-level event
message record.

TYPE  HighLevelEventMsg =
      RECORD
         HighLevelEventMsgHeaderLength:      Integer;
         version:                            Integer;
         reserved1:                          LongInt;
         theMsgEvent:                        EventRecord;
         userRefCon:                         LongInt;
         postingOptions:                     LongInt;
         msgLength:                          LongInt;
      END;

Field Description

HighLevelEventMsgHeaderLength

Reserved for use by the Event Manager.

version

Reserved for use by the Event Manager.

reserved1

Reserved for use by the Event Manager.

theMsgEvent

The event record of a high-level event. Your filter function can compare the fields of this event record to determine whether the high-level event is the desired event. If your filter function finds the desired event, it should call AcceptHighLevelEvent to accept the event and remove the event from the high-level event queue, and return TRUE as its function result.

userRefCon

A unique number that identifies the communication associated with this event.

postingOptions

Reserved for use by the Event Manager.

msgLength

Reserved for use by the Event Manager.