Notes: Use these constants to select which types of events should be included when

GetOSEvent, or OSEventAvail. They are also used in specifying one or

more event types in calls to FlushEvents and SetEventMask.

Note that networkMask, driverMask, app1Mask, app2Mask, app3Mask and

As bit flags, you can add or remove events via bitwise logical operations:

GetNextEvent( updateMask | activMask ); /* two event type only */

GetNextEvent( everyEvent & ~diskMask); /* all but disk events */

Each type of event is associated with a named constant used in processing

The following three constants have been added in System 7 in order to

msgWasPartiallyAccepted = 2

msgWasFullyAccepted = 1

msgWasNotAccepted = 0

HighLevelEventMsgClass = 'jaym';

rtrnReceiptMsgID = 'rtrn';

mDownMask 2; [TOKEN:12079] mouseDown

mUpMask 4; [TOKEN:12079] mouseUp

keyDownMask 8; [TOKEN:12079] keyDown

keyUpMask 16; [TOKEN:12079] keyUp

autoKeyMask 32; [TOKEN:12079] autoKey

updateMask 64; [TOKEN:12079] update

diskMask 128; // disk-inserted

activMask 256; // activate

Several of the Event Manager routines can be restricted to operate on a

specific event type or group of types. You do this by disabling (or “masking

out”) the events you are not interested in receiving. To specify which event

types a Event Manager routine governs, supply a parameter known as an

eventMask. Masks for each individual event type are available as pre defined

You can form any particular mask you need from the mask constants. ORing

two mask constants together effectively adds them. ANDing the complement of

For example, to request the next available event that is not a mouseUp event,

myErr=WaitNextEvent(everyEvent & ~mUpMask, &myEvent, mySleep,

myRgnHnd);

Note that masking out types of events does not remove those events from the

Operating System event queue. If a type of event is masked out, it is simply

ignored by the Event Manager when it reads the event queue. Note also that

you cannot mask out null events. Even if every other kind of event is disabled,

In System 7.0+, you can mask out high-level events by subtracting the

constant highLevelEventMask from your event mask. (This constant has the