Open Radar

 
Summary:
It certain circumstances, it would be desirable to create an NSWindowController subclass which doesn't have a corresponding XIB.  One very sensible way to do this would be to override -loadWindow.

This works just fine if -windowNibName is implemented to return something non-nil.  However, if one does not have a NIB, one would not expect to have to provide a NIB name.

This seems to be due to the implementation of -[NSWindowController isWindowLoaded] which apparently checks whether _wcFlags.nibIsLoaded is 0 and whether windowNibName is nil.  Here's the decompilation from Hopper.app:

char -[NSWindowController isWindowLoaded](void * self, void * sel) {
    rdi = self;
    LOBYTE(rax) = 0x1;
    if ((rdi->_wcFlags & 0x4) == 0x0) {
            rax = [rdi windowNibName];
            LOBYTE(rax) = rax == 0x0 ? 0x1 : 0x0;
    }
    LODWORD(rax) = LOBYTE(rax) & 0xff;
    return rax;
}

which massages into

- (BOOL)isWindowLoaded {
    BOOL result = YES;

    if (!_wcFlags.nibIsLoaded) {
        if ([self windowNibName] = nil) {
            result = YES;
        } else {
            result = NO;
        }
    }

    return result;
}

This means that if windowNibName is nil, isWindowLoaded returns YES.

When creating an NSWindowController subclass without a corresponding XIB file, if one only overrides loadWindow to programmatically create an NSWindow to assign to self.window but does not override windowNibName to return a non-nil object, loadWindow will never be called.

Steps to Reproduce:
1. Open the attached project.  ( http://cl.ly/3Q3u162c0F17 )
2. Open WindowController.m and observe the implementation of windowNibName:

// COMMENT ME OUT!
- (NSString *)windowNibName
{
    return @"nonsense";
}

3. Run the app.  You will see a window presented.
4. Comment out windowNibName in WindowController.m.
5. Run the app.  You will not see a window presented.

Expected Results:
An NSWindowController subclass which programmatically creates its window in loadWindow should function properly without windowNibName being non-nil.

Actual Results:
When creating an NSWindowController subclass that implements loadWindow to programmatically create a window, it is necessary to ensure that windowNibName is non-nil, either by overriding the method to return a non-nil value or by passing one to the initializer (-initWithWindowNibName:owner:).

Version:
Xcode 6.2 Beta 2, OS X 10.10.1.

Notes:


Configuration:


Attachments:
'ProgrammaticWindowControllerDemo.zip' was successfully uploaded.