Re: NSTextField questions

[David Ayers]

Dirk Lattermann wrote:

> The delegate of the NSTextField doesn't get a
> controlTextDidBeginEditing: message. It works with
> controlTextDidChange: and ...EndEditing.
> In fact, I think NSTextField itself doesn't receive
> textDidBeginEditing, which I found out when subclassing NSTextField.
>  
Sorry for answering so late, but I hardly had time to actually do some 
debugging here.  Thus far it seems that the BEGAN_EDITING macro in 
NSTextView's shouldChangeTextInRange:replacementString: doesn't return 
YES when the actual editing begins. This is the method that is supposed 
to post the notifcation. I'll try to continue to find out what's going on.

> The question is: how can I figure out when an NSTextField has just
> become the firstResponder? Is there a notification that is sent
> in this case?
> (this might be related to the bug above because I don't know if
> textDidBeginEditing is supposed to be used for this or if it is sent
> after the first editing key press in a text field).
>  
Well not really, the is no notification sent when an object becomes 
firstResponder. The NSControlTextDidBeginEditingNotification should be 
sent once a key is pressed. (But as noticed this isn't working.) In fact 
it's not that easy to trace this currently. NSTextFields mechanism for 
becoming firstResponder is not working correctly at the moment, but I 
believe Nicola is working on a solution there.

But even once he has fixed it, it is not necessarily trivial. When you 
tell an NSWindow to make an NSTextField firstResponder through the 
makeFirstResponder method, it ultamtliy should do this by invoking 
NSTextField's becomeFirstResponder. It is the responsiblity of the 
NSTextField, to propagate the firstResponder to the window's 
fieldEditor, which is an NSTextView shared by all NSTextFields of the 
window. Everytime another NSTextField's becomeFirstResponder is invoked, 
it takes this shared NSTextView and sets it up for it's needs, makes it 
firstResponder therefor the NSTextField resignsFirstResponder, before 
the original becomeFirstResponder will return.

I just went through describing this to show that in an event cycle the 
firstResponder status is very volatile. It would make more sens to ask 
the Window for it's current firstResponder in some defined state (for 
example when processing an action method.)

Maybe you could detail a bit more of what you want to do. And I'll look 
into the notification bug.

Cheers,
Dave