Question

I have a very simple project. Extremely watered down. All it does is load some text into an NSTableView. That’s it. But it’s using a new window and controller, called “Revisions.”

As soon as the new window becomes active, it crashes or just locks up. No errors in the console. If it sits in the background, behind the AppDelegate’s window, it appears to load the information fine. I can see the table is populated perfectly. But as soon as I click on the window and make it active, it crashes/locks.

This is driving me nuts. I know it has to do with memory management, but I can’t figure out where or how or why.

Note, I’m in XCode 4.2, where there’s no more releasin’ (unless I change some settings, of course).

All connections in

AppDelegate.h

#import <Cocoa/Cocoa.h>
@interface AppDelegate : NSObject <NSApplicationDelegate>
@property (assign) IBOutlet NSWindow *window;
@end

AppDelegate.m

#import "AppDelegate.h"
#import "Revisions.h"

@implementation AppDelegate

@synthesize window = _window;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{    
    Revisions *rev = [[Revisions alloc] initWithWindowNibName:@"Revisions"];
    [rev loadWindow];    
}

Revisions.h

#import <Cocoa/Cocoa.h>

@interface Revisions : NSWindowController
{    
    IBOutlet NSTableView *quicktimesList;
    IBOutlet NSTableView *unusedDataList;   
}

@end

Revisions.m

#import "Revisions.h"

@implementation Revisions


- (id)initWithWindow:(NSWindow *)window
{
    self = [super initWithWindow:window];
    if (self) {
        // Initialization code here.
    }

    return self;
}

- (void)windowDidLoad
{
    [super windowDidLoad];    
    // Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}


- (NSInteger)numberOfRowsInTableView:(NSTableView *)aTableView
{
    NSLog(@"Creating number of rows.");
    return 10;
}

- (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)rowIndex
{
    NSLog(@"Starting Loop.");
    NSString *words = [[NSString alloc] initWithFormat:@"Row %i", rowIndex];
    NSLog(@"Looping %i", (int)rowIndex);
    return words;
}

@end

Answer 1

Ok. I’m going to give you a couple of tips when dealing with potential memory leaks in Xcode 4.2.

1. When writing software for Mac it is advisable to enable garbage collection in your build settings. Just simply search for “garbage collection” in the search bar of your build settings and set it to “required”.

2. If you have memory leaks in your project just press the “product” menu and hit “Analyze”.This does as the menu item states, it analyses your project for potential memory leaks and helps you track them down.

Hope this helps!