In my application I want to get notified if something is added into the NSPasteboard. If I copy an text from any other program I want my application to know about it.
Somewhere I read it can't be done that way. I should create a timer and check the content of the NSPasteboard myself.
Is this the way to do? Or are there any kind of notifications?
Yes, you essentially have to poll the pasteboard to see if its contents have changed. It's not ideal, but it's possible. Basically, you have a timer that fires once or twice a second and checks the -[NSPasteboard changeCount]. If the changeCount changes, that means the contents of the pasteboard have also changed (or there's at least a new owner).