Important: The Event Manager is a legacy System 7 technology. You should use the Mac OS X Carbon Event Manager instead. See Carbon Event Manager Programming Guide.
A function identified as deprecated has been superseded and may become unsupported in the future.
Changes the keyboard script (the script system used for keyboard input), changes the keyboard layout (the mapping of keys to characters) or input method within the current keyboard script (a facility for entering 2-byte characters), or makes a setting related to text input, using the supplied value. (Deprecated in Mac OS X v10.5.)
void KeyScript ( short code );
If 0 or positive, directly specifies a script system (that is, it is read as a script code). Negative values have special meanings.
The code parameter is a selector that can explicitly specify a keyboard script by script code. See the Script Manager for a list of script codes. If the selector specifies a script, then the current default keyboard layout ('KCHR' resource) for that script, as specified in the script’s international bundle resource, becomes the current keyboard layout.
The selector can also implicitly specify a keyboard script (for example, the next script), a keyboard layout (for example, the previously used keyboard layout in the current script), or an input method (for example, inline input versus window-based input). It can also specify settings that enable or disable keyboard layouts and keyboard scripts, and toggle among input options or line direction.
For the purposes of KeyScript, keyboard layout means a keyboard-layout ( 'KCHR') resource, plus optionally a key-remap ( 'itlk') resource. To change keyboard layouts means to change the current keyboard-layout resource.
If the Keyboard menu is displayed, KeyScript also updates the Keyboard menu.
If you call KeyScript and explicitly specify a script system that is not available, KeyScript does nothing. The current keyboard script remains unchanged.
Note that Keyscript also does nothing when passed a positive or zero script code if the user has Font and Keyboard Synchronization turned off. You can find the Font and Synchronization checkbox under Options in the Input Menu tab of the International System Preference in Mac OS X.
KeyScript operates only on those keyboard-layout and key-remap resources that are present in the System file.
Your application’s keyboard-menu setting is not maintained by the Process Manager if the state of the keyboard menu is changed while you are switched out, the Process Manager does not restore your setting when you are switched back in. However, the Process Manager does maintain the keyboard disable state (Script Manager variable smKeyDisableState) for your application. See the Script Manager for a description of the smKeyDisableState variable. KeyScript may move memory; your application should not call this function at interrupt time.
Events.hRetrieves the next available event from the Event Manager without removing the returned event from your application’s event stream. (Deprecated in Mac OS X v10.6.)
Boolean EventAvail ( EventMask eventMask, EventRecord *theEvent );
A value that indicates which kinds of events
are to be returned; this parameter is interpreted as a sum of event
mask constants. You specify the event mask using one or more of
the values defined by the “Event Mask Constants.” If no event of any of the designated
types is available, EventAvail returns
a null event.
A pointer to an event structure for the next
available event of the specified type or types. The EventAvail function
does not remove the returned event from the event stream, but does
return the information about the event in an event structure. The
event structure includes the type of event received and other information.
EventAvail returns false as
its function result if the event being returned is a null event;
otherwise, EventAvail returns true.
If EventAvail returns
a low-level event from the Operating System event queue, the event
will not be accessible later if, in the meantime, the event queue
becomes full and the event is discarded from it; however, this is
not a common occurrence.
Events.hRemoves low-level events from the Operating System event queue. (Deprecated in Mac OS X v10.6.)
void FlushEvents ( EventMask whichMask, EventMask stopMask );
A value that indicates which kinds of low-level
events are to be removed from the Operating System event queue;
this parameter is interpreted as a sum of event mask constants.
You specify the event mask using one or more of the values defined
in “Event Mask Constants.”
The whichMask and stopMask parameters
together specify which events to remove.
A value that limits which low-level events
are to be removed from the Operating System event queue; this parameter
is interpreted as a sum of event mask constants. You specify the
event mask using one or more of the values defined in “Event Mask Constants.” FlushEvents does
not remove any low-level events that are specified by the stopMask parameter.
To remove all events specified by the whichMask parameter,
specify 0 as the stopMask parameter.
FlushEvents removes
only low-level events stored in the Operating System event queue;
it does not remove activate, update, operating-system, or high-level
events. FlushEvents does not
remove any types of events not stored in the Operating System event
queue.
You can choose to use the FlushEvents function
when your application first starts to empty the Operating System
event queue of any keystrokes or mouse events generated by the user
while the Finder loaded your application. In general, however, your
application should not empty the queue at any other time as this
loses user actions and makes your application and the computer appear
unresponsive to the user.
You specify which low-level events to remove using the whichMask and stopMask parameters. FlushEvents removes
the low-level events specified by the whichMask parameter,
up to but not including the first event of any type specified by
the stopMask parameter.
If the event queue doesn’t contain any of the events specified
by the whichMask parameter, FlushEvents does
not remove any events from the queue.
Events.hRetrieves events one at a time from the Event Manager. (Deprecated in Mac OS X v10.6.)
Boolean GetNextEvent ( EventMask eventMask, EventRecord *theEvent );
A value that indicates which kinds of events
are to be returned; this parameter is interpreted as a sum of event
mask constants. You specify the event mask using one or more of
the values defined in “Event Mask Constants.” If no event of any of the designated types
is available, GetNextEvent returns a
null event.
A pointer to an event structure for the next
available event of the specified type or types. The GetNextEvent function
removes the returned event from the event stream and returns the
information about the event in an event structure. The event structure
includes the type of event received and other information.
GetNextEvent returns false as
its function result if the event being returned is a null event
or if GetNextEvent has
intercepted the event; otherwise, GetNextEvent returns true.
The GetNextEvent function
calls the Operating System Manager function SystemEvent to
determine whether the event should be handled by the application
or the Operating System.
The GetNextEvent function also intercepts Command–Shift–number key sequences and calls the corresponding 'FKEY' resource to perform the associated action. The Event Manager’s processing of Command–Shift–number key sequences with numbers 3 through 9 can be disabled by setting the ScrDmpEnable global variable (a byte) to 0.
For greater support of the multitasking environment, your application should use WaitNextEvent instead of GetNextEvent whenever possible.
Events.hTests whether the Command key is pressed in conjunction with another key (or keys) that could generate the specified test character. (Deprecated in Mac OS X v10.6.)
Boolean IsCmdChar ( const EventRecord *event, short test );
The event record for a key-down or auto-key event with the Command key down.
The character you want to test.
The function returns TRUE if
the test character is produced with the current modifier keys, or
if it would be produced by changing the current modifier key bits
in either or both of the following ways: (1) turning the Command bit
off or (2) toggling the Shift bit.
This function tests whether the Command key is pressed in
conjunction with another key (or keys) that could generate the test character
for some combination of Command up or down and Shift up or down.
This accommodates European keyboards that may have the test character
as a shifted character, and non-Roman keyboards that will only generate
the test character if
the Command key is pressed. It's most useful for testing for Command-period,
but it can test for command-AnyCharacter.
Events.hConverts a virtual key code to a character code based on a 'KCHR' resource. (Deprecated in Mac OS X v10.6.)
UInt32 KeyTranslate ( const void *transData, UInt16 keycode, UInt32 *state );
A pointer to the 'KCHR' resource that you want the KeyTranslate function to use when converting the key code to a character code.
A 16-bit value that your application should set so that bits 0–6 contain the virtual key code and bit 7 contains either 1 to indicate an up stroke or 0 to indicate a down stroke of the key. Bits 8–15 have the same interpretation as the high byte of the modifiers field of the event structure and should be set according to the needs of your application.
A pointer to a value that your application should set to 0 the first time it calls KeyTranslate or any time your application calls KeyTranslate with a different 'KCHR' resource. Thereafter, your application should pass the same value in the state parameter as KeyTranslate returned in the previous call.
A 32-bit value that gives the character code for the virtual key code specified by the keycode parameter.
The KeyTranslate function returns the values that correspond to one or possibly two characters that are generated by the specified virtual key code. The following diagram shows the structure of the 32-bit number that KeyTranslate returns.
31 24 23 16 15 8 7 0 |
--------------------------------------------------------------------- |
| | | | | |
--------------------------------------------------------------------- |
Reserved 1 Character code 1 Reserved 2 Character code 2 |
For example, a given virtual key code might correspond to an alphabetic character with a separate accent character. When the user presses Option-E followed by E, you can map this through the KeyTranslate function using the U.S. 'KCHR' resource to produce é, which KeyTranslate returns as two characters in the bytes labeled Character code 1 and Character code 2.
If KeyTranslate returns only one character code, it is always in the byte labeled Character code 2. However, your application should always check both bytes labeled Character code 1 and Character code 2 for possible values that map to the virtual key code.
Events.hPosts events into the Operating System event queue. (Deprecated in Mac OS X v10.6.)
OSErr PostEvent ( EventKind eventNum, UInt32 eventMsg );
A value that indicates the type of event to
post into the Operating System event queue. You specify the event
kind using one or more of these values defined in “Event Mask Constants”: mouseDown, mouseUp, keyDown, keyUp, autoKey,
and diskEvt. Do not attempt
to post any other type of event in the Operating System event queue.
An unsigned integer that contains the contents
of the message field
for the event that PostEvent should
post in the queue.
A result code. See “Event Manager Result Codes.”
In the eventNum and eventMsg parameters,
you specify the value for the what and message fields of
the event’s event structure. The PostEvent function
fills out the when, where,
and modifiers fields of
the event structure with the current time, current mouse location,
and current state of the modifier keys and mouse button.
The PostEvent function
posts only events that are enabled by the system event mask. If
the event queue is full, PostEvent removes
the oldest event in the queue and posts the new event.
Note that if you use PostEvent to
repost an event, the PostEvent function
fills out the when, where, and modifier fields
of the event structure, giving these fields of the reposted event
different values from the values contained in the original event.
Do not post any events other than mouse-down, mouse-up, key-down, key-up, auto-key, and disk-inserted events in the Operating System event queue. Attempting to post other events into the Operating System event queue interferes with the internal operation of the Event Manager.
In most cases, your application should not call the PostEvent function.
Events.hRetrieves events one at a time from the Event Manager. (Deprecated in Mac OS X v10.6.)
Boolean WaitNextEvent ( EventMask eventMask, EventRecord *theEvent, UInt32 sleep, RgnHandle mouseRgn );
A value that indicates which kinds of events
are to be returned. This parameter is interpreted as a sum of event
mask constants. You specify the event mask using values defined
in “Event Mask Constants.”
To accept all events, you can specify the everyEvent constant
as the event mask.
If no event of any of the designated types
is available, WaitNextEvent returns
a null event. WaitNextEvent determines
the next available event to return based on the eventMask parameter
and the priority of the event.
Events not designated by the event mask remain in the event stream until retrieved by an application. Low-level events in the Operating System event queue are kept in the queue until they are retrieved by your application or another application or until the queue becomes full. Once the queue becomes full, the Operating System Event Manager begins discarding the oldest events in the queue.
A pointer to an event structure for the next
available event of the specified type or types. The WaitNextEvent function
removes the returned event from the event stream and returns the
information about the event in an event structure. The event structure
includes the type of event received and other information.
In
addition to the event structure, high-level events can contain additional data;
use the Apple Event Manager AEProcessAppleEvent function
to get additional data associated with these events.
The number of ticks (a tick is approximately
1/60 of a second) indicating the amount of time your application
is willing to relinquish the processor if no events are pending
for your application. If you specify a value greater than 0 for
the sleep parameter,
your application relinquishes the processor for the specified time
or until an event occurs.
You should not set the sleep parameter
to a value greater than the number of ticks returned by GetCaretTime if
your application provides text-editing capabilities. When the specified
time expires, and if there are no pending events for your application, WaitNextEvent returns
a NULL event in the parameter theEvent.
When
running on Mac OS X, a Carbon application will block for the entire duration
of the sleep parameter
if there are no events to be delivered. This is slightly different
behavior than on Mac OS 9, where the application will often receive NULL events
before the sleep duration has elapsed.
A handle to a region that specifies a region
inside of which mouse movement does not cause mouse-moved events.
In other words, your application receives mouse-moved events only
when the cursor is outside the specified region. You should specify
the region in global coordinates. If you pass an empty region or
a null region handle,
the Event Manager does not report mouse-moved events to your application.
Note that your application should recalculate the mouseRgn parameter
when it receives a mouse-moved event, or it will continue to receive
mouse-moved events as long as the cursor position is outside the
original mouseRgn.
The WaitNextEvent function
returns false as its
function result if the event being returned is a null event or if WaitNextEvent has
intercepted the event; otherwise, WaitNextEvent returns true.
The WaitNextEvent function
calls the Operating System Event Manager function SystemEvent to determine
whether the event should be handled by the application or the Operating System.
If no events are pending for your application, WaitNextEvent waits
for a specified amount of time for an event. (During this time,
processing time may be allocated to background processes.) If an
event occurs, it is returned through the parameter theEvent,
and WaitNextEvent returns
a function result of true.
If the specified time expires and there are no pending events for
your application, WaitNextEvent returns
a null event in theEvent and
a function result of false.
Before returning an event to your application, WaitNextEvent performs
other processing and may intercept the event.
The WaitNextEvent function
intercepts Command–Shift–number key sequences and calls the corresponding
' FKEY ' resource to
perform the associated action. The Event Manager’s processing
of Command–Shift–number key sequences with numbers 3 through
9 can be disabled by setting the ScrDmpEnable global
variable (a byte) to 0.
If the returned event is a high-level event and your application
supports Apple events, use the Apple Event Manager function AEProcessAppleEvent to
respond to the Apple event and to get additional information associated
with the Apple event.
To retrieve an event without removing it from the event stream,
use EventAvail.
Events.hLast updated: 2007-10-31
