How do i detect keystrokes using objective c?

Question

Hi, just wondering, how I go about detecting different keystrokes, and then detecting what key has been pressed I tried using this, - (void)keyDown:(NSEvent *)event but didnt seem to get any results. I've also had a search around but didn't find anything. I'm guessing I may have to set up something in interface builder to detect keystrokes? I also think that it has something to do with what is selected, if its a text field something. thanks.

Answer 1

keyDown: method is called only for certain view and it's subviews I think. If you need all keystrokes for your app - check NSEvent class method:

+ (id)addLocalMonitorForEventsMatchingMask:(NSEventMask)mask 
                                   handler:(NSEvent* (^)(NSEvent*))block

Read upon in it XCode documentation. I presume you're on snow leopard.

Answer 2

I tried using this, - (void)keyDown:(NSEvent *)event but didnt seem to get any results.

What do you mean “using” it?

You need one of your objects to respond to that message. That means you need it to be a responder, and to be in the responder chain whenever it is appropriate for the keystrokes it handles to be pressed.

Depending on what the keypress does, it may be appropriate for a single custom view to handle it; if not, it should probably be the window controller that handles it. Either one should already be in the responder chain at the appropriate times. Whichever way you go, you'll need to subclass either NSView (for a custom view) or NSWindowController.