- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    // init the preferences window controller
    self.preferences = [CCNPreferencesWindowController new];
    self.preferences.centerToolbarItems = YES;  // or NO

    // setup all preference view controllers
    [self.preferences setPreferencesViewControllers:@[
        [PreferencesGeneralViewController new],
        [PreferencesNetworkViewController new],
        [PreferencesBonjourViewController new]
    ]];
}

- (IBAction)showPreferencesWindow:(id)sender {
    [self.preferences showPreferencesWindow];
}