Re: Toplevel Objects in NIB files
Re: Toplevel Objects in NIB files
- Subject: Re: Toplevel Objects in NIB files
- From: James DiPalma <email@hidden>
- Date: Tue, 17 Sep 2002 18:08:19 -0400
I'm glad to see Ondra fighting to get Apple and others to recommend and
obey Apple's object ownership rules. I hope someone is listening. As for
me, I should not have suggested that it didn't matter if you release
NSFontManager; especially since some testing shows that it does matter.
For a practical example, I did this on both 10.1 and 10.2:
In PB, create new document based application
In IB, add an NSMenu and a "Font" menu item to "MyDocument.nib"
Build and run
Close initial window
Open new window
sharedFontManager returns nil (*) resulting in an exception:
Test[] *** -[NSCFArray addObject:]: attempt to insert nil
I demonstrated problems with NSFontManager in a discussion titled "Weird
problem with documents SOLVED" here:
http://cocoa.mamasam.com/COCOADEV/2002/07/1/39688.php
Basically, [[NSFontManager alloc] init] does not return an instance with
a retain count of +1 and NSWindowController happily releases all
top-level objects including a NSFontManager shared instance.
Ondra is right, I hope no one is surprised, Apple should not require us
to special case top-level objects that happen to be shared instances.
Code that obeys object ownership rules defined in Apple's documentation
should have no trouble getting released by NSWindowController.
(*) sharedFontManager returns nil because NSFontManager's dealloc method
sets it to nil (which it should do), but subsequent
init/sharedFontManager calls do not alloc/init a new instance.
-jim
From: Ondra Cada <email@hidden>
From: Vince DeMarco <email@hidden>
Don't release the Font Manager, its a shared instance in the AppKit.
There is only one.
Nevertheless, correct me please if I am wrong, but I believe that it
should (and easily could) be fixed by retaining ("overretaining") it
when a NIB is loaded, to comply with the general behaviour that all NIB
top-level objects are retained (or, more precisely, created and not
autoreleased).
I believe such a change would break no backward compatibility, since so
far nobody could release it lest the app do weird things; if you add
the retain, anyone would be able to consistently release all top-level
objects from a NIB as soon as it is needed no more, whilst the fact
Font Manager is actually a shared object would be encapsulated under
the API level, which I think is the right way to do such things.
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