Most idiomatic iOS5 way of customizing the UINavigationBar? - iphone

Question

I'm working on customizing the appearance of navigation controllers in my app to look like the following:
As I've discovered after a few hours of SO research, there are a ton of different ways of doing it, some really hackish, some much less so. I'm interested in finding out the Apple-blessed / most elegant way of achieving this that will lead to the least amount of pain down the road as the app grows. Some approaches I've looked into so far:
1) I changed the background / height of the navigation bar by applying an image through [UINavigationBar appearance], seems to have worked fine.
UIImage *navBarImage = [UIImage imageNamed:#"navigation-bar.png"];
[[UINavigationBar appearance] setBackgroundImage:navBarImage
forBarMetrics:UIBarMetricsDefault];
Seems like the most "modern" way of achieving background/height change, although it most likely doesn't survive an orientation change. Any improvements that could be made here?
2) I replaced the default back button with the following in the viewDidLoad of the pushed view
// Set the custom back button
UIImage *buttonImage = [UIImage imageNamed:#"back.png"];
//create the button and assign the image
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
//set the frame of the button to the size of the image (see note below)
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:self action:#selector(back) forControlEvents:UIControlEventTouchUpInside];
// offset the back button
button.contentEdgeInsets = UIEdgeInsetsMake(10, 5, -10, -5);
//create a UIBarButtonItem with the button as a custom view
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = customBarItem;
I'm not very pleased with this solution because it leaves customization of the bar to the controller on top of the navigation stack. From the Apple docs it would seem like they'd prefer you to subclass the UINavigationBar altogether and replace it once and for all in the navigation controller:
You can also specify a custom UINavigationBar subclass by using the initWithNavigationBarClass:toolbarClass: method to initialize the navigation controller.
Would that be the advised route? I was NOT able to replace the default Back button of the UINavigationBar through [UIBarButtonItem appearance] as it still attempts to display text in the button, and when you remove the text, the button isn't displayed at all. Suggestions?
3) The page title should be replaceable with another view through navigationItem.titleView. Anything better out there?
Thanks!

Answer 1

1) You should set two images, for two UIBarMetrics (UIBarMetricsDefault and a separate image for UIBarMetricsLandscapePhone). Thus
UIImage *navBarImage = [UIImage imageNamed:#"navigation-bar.png"];
UIImage *navBarImage_Landscape = [UIImage imageNamed:#"navigation-bar-landscape.png"];
[[UINavigationBar appearance] setBackgroundImage:navBarImage
forBarMetrics:UIBarMetricsDefault];
[[UINavigationBar appearance] setBackgroundImage:navBarImage_Landscape
forBarMetrics:UIBarMetricsLandscapePhone];
2) You could either subclass UINavigationBar (as you've also mentioned and that would be the default Apple way). Or if it's just the button, maybe you could hack its behaviour by passing in " " (empty text)
3) Not sure what you meant. You could setTitle of the navigation bar and it would show whatever title you want. Or you should be able to plug in another view for titleView
Note that setBackgroundImage is iOS 5.0 and later.