Cocoa: NSView not drawing rect

I have a class called ServerImage (sub of NSView) which I am calling from my AppController but for some reason it won't draw to the screen. I have other views which I am able to draw and add images to but for some reason not this one. I'm sure I am missing something in my code but am just not seeing it. Here's the relevant code from AppController:

//loop through masterServerDict and get server status   
NSMutableString* key; 
for(key in masterServerDict) { 

    ServerImage* newImage = [[ServerImage alloc] initWithFrame:NSMakeRect(200.0, 0.0, 48.0, 48.0)];

    [newImage setServerName:key];
    [[[NSApp mainWindow] contentView] addSubview:newImage];
    [newImage setNeedsDisplay:YES];


}

masterServerDict is a mutable dictionary, the key is the name of a server, the object is an array, it holds the smb and afp paths to the server and whether it is mounted or not.

Here is ServerImage.h

#import <Cocoa/Cocoa.h>


    @interface ServerImage : NSView {

        NSString * serverName; 
    }

    - (void) setServerName : (NSString* ) s; 

@end

and ServerImage.m

#import "ServerImage.h"


@implementation ServerImage

    - (id)initWithFrame:(NSRect)frame {

        self = [super initWithFrame:frame];
        if (self) {
            // Initialization code here.
            NSLog(@"%f", self.frame.orig开发者_如何转开发in.x);
        }

        return self;
    }

- (void)drawRect:(NSRect)rect {
    NSLog(@"drawrect");
    [[NSColor redColor] set]; 
    NSRectFill(rect);
}

- (void) setServerName : (NSString* ) s { 
    NSLog(@"method");
    serverName = s; 

}

I can get the init and setServerName methods to log but not drawRect...

Check if [[NSApp mainWindow] contentView] is non-nil. Also check if it refers to the right window and that the coordinate is good (visible).