Removing shine effect from the buttons in a UINavigationBar

gistfile1.m

// http://pastebin.com/raw.php?i=Xdf49BgK

@interface UIBarButtonItem (UIBarButtonItem_customBackground)

+ (id) customBarButtonWithTitle:(NSString *)title target:(id)target selector:(SEL)selector;
+ (id) customBackButtonWithTitle:(NSString *)title target:(id)target selector:(SEL)selector;

@end

@implementation UIBarButtonItem (UIBarButtonItem_customBackground)

+ (id) customButtonWithImageNamed:(NSString *)imageName selectedImageNamed:(NSString *)selectedImageName leftCapWidth:(CGFloat)leftCapWidth edgeInsets:(UIEdgeInsets)edgeInsets title:(NSString *)title target:(id)target selector:(SEL)selector {
    UIButton* customButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [customButton addTarget:target action:selector forControlEvents:UIControlEventTouchUpInside];
    customButton.titleLabel.font = [UIFont boldSystemFontOfSize:12.0f];
    customButton.titleLabel.shadowColor = [UIColor colorWithRed:0.0f/255.0f green:0.0f/255.0f blue:0.0f/255.0f alpha:0.25f];
    customButton.titleLabel.shadowOffset = CGSizeMake(0.0f, -1.0f);
    customButton.titleLabel.lineBreakMode = UILineBreakModeTailTruncation;
    customButton.titleEdgeInsets = edgeInsets;
    UIImage* navButtonBackgroundImage = [[UIImage imageNamed:imageName] stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:0.0f];
    UIImage* navButtonPressedBackgroundImage = [[UIImage imageNamed:selectedImageName] stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:0.0f];
    [customButton setBackgroundImage:navButtonBackgroundImage forState:UIControlStateNormal];
    [customButton setTitle:title forState:UIControlStateNormal];
    [customButton setBackgroundImage:navButtonPressedBackgroundImage forState:UIControlStateHighlighted];
    [customButton setBackgroundImage:navButtonPressedBackgroundImage forState:UIControlStateSelected];

    CGSize size = CGSizeMake(30.0f, 30.0f);
    if (title != nil) {
        size = [[NSString stringWithString:title] sizeWithFont:customButton.titleLabel.font];
    }
    customButton.frame = CGRectMake(0.0f, 0.0f, size.width + 20.0f, 30.0f);
    customButton.layer.shouldRasterize = YES;
    customButton.layer.rasterizationScale = [[UIScreen mainScreen] scale];
    return [[[UIBarButtonItem alloc] initWithCustomView:customButton] autorelease];
}

+ (id) customBarButtonWithTitle:(NSString *)title target:(id)target selector:(SEL)selector {
    return [self customButtonWithImageNamed:@"navButtonBG.png" 
                 selectedImageNamed:@"navButtonPressedBG.png" 
                       leftCapWidth:6.0f 
                         edgeInsets:UIEdgeInsetsMake(0.0f, 5.0f, 0.0f, 5.0f) 
                              title:title 
                             target:target 
                           selector:selector];
}

+ (id) customBackButtonWithTitle:(NSString *)title target:(id)target selector:(SEL)selector {    
    return [self customButtonWithImageNamed:@"backButtonBG.png" 
                 selectedImageNamed:@"backButtonPressedBG.png" 
                       leftCapWidth:12.0f 
                         edgeInsets:UIEdgeInsetsMake(0.0f, 11.0f, 0.0f, 5.0f) 
                              title:title 
                             target:target 
                           selector:selector];
}

@end
  
UIBarButtonItem* logoutButton = [UIBarButtonItem customBarButtonWithTitle:@"Logout" target:self selector:@selector(logout)];
self.navigationItem.rightBarButtonItem = logoutButton;
	
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    if([navigationController.viewControllers count ] > 1) {
        UIViewController* backViewController = [navigationController.viewControllers objectAtIndex:(navigationController.viewControllers.count - 2)];
        NSString* backText = backViewController.title;
        UIBarButtonItem* newBackButton = [UIBarButtonItem customBackButtonWithTitle:backText target:navigationController selector:@selector(popViewControllerAnimated:)];
        viewController.navigationItem.leftBarButtonItem = newBackButton;
        viewController.navigationItem.hidesBackButton = YES;
    }
}