Implementing NSText delegate methods in PyObjc and Cocoa

Question

In the project that I'm building, I'd like to have a method called when I paste some text into a specific text field. I can't seem to get this to work, but here's what I've tried

I implimented a custom class (based on NSObject) to be a delegate for my textfield, then gave it the method: textDidChange:

class textFieldDelegate(NSObject):
    def textDidChange_(self, notification):
        NSLog("textdidchange")

I then instantiated an object of this class in interface builder, and set it to be the delegate of the NSTextField. This however, doesn't seem to do anything. However, when I build the example code from http://www.programmish.com/?p=30, everything seems to work perfectly fine. How do I impliment this delegate code so that it actually works?

Answer 1

The reason this isn't working for you is that textDidChange_ isn't a delegate method. It's a method on the NSTextField that posts the notification of the change. If you have peek at the docs for textDidChange, you'll see that it mentions the actual name of the delegate method:

This method causes the receiver’s delegate to receive a controlTextDidChange: message. See the NSControl class specification for more information on the text delegate method.

The delegate method is actually called controlTextDidChange_ and is declared on the NSTextField superclass, NSControl.

Change your delegate method to:

def controlTextDidChange_(self, notification):
    NSLog("textdidchange")

and it should work for you.