Первое, что я скажу вам, это то, что вы НЕ МОЖЕТЕ делать это без включения пользователем поддержки вспомогательных устройств на панели управления доступом. Это какая-то защита, встроенная в OSX.
Вот фрагмент кода, который я использую в одном из своих приложений для этого:
//this method calls a carbon method to attach a global event handler
- (void)attachEventHandlers
{
//create our event type spec for the keyup
EventTypeSpec eventType;
eventType.eventClass = kEventClassKeyboard;
eventType.eventKind = kEventRawKeyUp;
//create a callback for our event to fire in
EventHandlerUPP handlerFunction = NewEventHandlerUPP(globalKeyPress);
//install the event handler
OSStatus err = InstallEventHandler(GetEventMonitorTarget(), handlerFunction, 1, &eventType, self, NULL);
//error checking
if( err )
{
//TODO: need an alert sheet here
NSLog(@"Error registering keyboard handler...%d", err);
}
//create our event type spec for the mouse events
EventTypeSpec eventTypeM;
eventTypeM.eventClass = kEventClassMouse;
eventTypeM.eventKind = kEventMouseUp;
//create a callback for our event to fire in
EventHandlerUPP handlerFunctionM = NewEventHandlerUPP(globalMousePress);
//install the event handler
OSStatus errM = InstallEventHandler(GetEventMonitorTarget(), handlerFunctionM, 1, &eventTypeM, self, NULL);
//error checking
if( errM )
{
//TODO: need an alert sheet here
NSLog(@"Error registering mouse handler...%d", err);
}
}
Вот пример метода обратного вызова, который я использую:
OSStatus globalKeyPress(EventHandlerCallRef nextHandler, EventRef theEvent, void *userData)
{
NSEvent *anEvent = [NSEvent eventWithEventRef:theEvent];
NSEventType type = [anEvent type];
WarStrokerApplication *application = (WarStrokerApplication*)userData;
//is it a key up event?
if( type == NSKeyUp)
{
//which key is it?
switch( [anEvent keyCode] )
{
case NUMERIC_KEYPAD_PLUS:
//this is the character we are using for our toggle
//call the handler function
[application toggleKeyPressed];
break;
//Comment this line back in to figure out the keykode for a particular character
default:
NSLog(@"Keypressed: %d, **%@**", [anEvent keyCode], [anEvent characters]);
break;
}
}
return CallNextEventHandler(nextHandler, theEvent);
}