Challenging text editing field problem

FROM : John Nairn
DATE : Mon Feb 11 23:21:41 2008

My interface has a tricky issue when text is edited to a previously 
empty field (due to way the new text changes the data which then 
changes the layout of the window). I am having trouble following all 
the events to make sure handle things in the correct order. The 
current issue being sure the user does not add more data until the 
application is ready for it. There are several issues but here is the 
first:

I have subclassed NSTextField to override some methods including 
becomeFirstResponder and resignFirstResponder. I was hoping to make 
use of resignFirstResponder, but when my window opens, the first 
editing fields gets the following messages:

1. [theField becomeFirstResponder]
2. [theField resignFirstResponder]

and then when the window is open, that field is still the first 
responder. I can understand getting the becomeFirstResponder message, 
but why does it get a resignFirstResponder message while it is still 
the first responder?

When I tab to next field, I get

1. [nextField becomeFirstResponder]
2. [nextField resignFirstResponder]

but I was expecting

1. [theField resignFirstResponder]
2. [nextField becomeFirstResponder]

My only thought is that when a text field becomes the first responder, 
it immediately gives it up to the field editor?


---------------
John Nairn (1-541-737-4265, FAX:1-541-737-3385)
Professor and Richardson Chair
Web Page: http://woodscience.oregonstate.edu/faculty/Nairn
FEA/MPM Web Page: http://oregonstate.edu/~nairnj