getting receiver class void for NSWindow

Question

I know this has to be something super simple, but can't for the life of me figure it out. I can't get XCode to recognize NSWindow as an objective-c class. I have the following simple code:

HelloWorldAppDelegate.h

#import  <Cocoa/Cocoa.h>
#import "EAGLView_mac.h"

@interface HelloWorldAppDelegate : NSObject <NSApplicationDelegate> {
    NSWindow    *window;
    EAGLView    *glView;
}

@property (assign) IBOutlet NSWindow    *window;
@property (assign) IBOutlet EAGLView    *glView;

@end

HelloWorldAppDelegate.m

#import "HelloWorldAppDelegate.h"
#import "EAGLView_mac.h"

@implementation HelloWorldAppDelegate
@synthesize window, glView;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    NSRect frame = NSMakeRect(0, 0, 480, 320);

    window = [[NSWindow alloc] initWithContentRect: frame styleMask:NSBorderlessWindowMask backing:NSBackingStoreBuffered defer:YES];

    //EAGL init code cut for brevity      

    [window setContent:glView];
    [window makeKeyAndOrderFront:self];
}

@end

When I try to compile XCode complains that NSWindow is a receiver type 'void' and not an objective-c class. None of the autocomplete functions popped up when I was typing up the code either. I get an actual error on the call to NSWindow alloc, and a warning on the other two calls to 'window' all complaining that window and/or NSWindow is a receiver type void. It also complains that the methods 'setContent' and 'makeKeyAndOrderFront' are not found? Am I missing an include somewhere?

If you create a brand new Cocoa App project with all of the default settings, does it have the same problem? If so, it's possible that your AppKit framework (either the one in /System/Library or the one in one of the Xcode SDKs) is broken… but I'd start by reinstalling Xcode and see if that works. — abarnert

bijan bijan · Accepted Answer · 2012-06-06T13:08:30

Try changing the property attribute of the NSWindow and EAGLView outlets to either

(nonatomic, retain), if you're not using ARC
(weak), if you're using ARC

The Objective-C Programming Language: Declared Properties explains this and states:

assign
Specifies that the setter uses simple assignment. This attribute is the default. You use this attribute for scalar types such as NSInteger and CGRect.

Hope this helps.

getting receiver class void for NSWindow

1 Answers