UINavigationBar autoresizing

ryyst picture ryyst · Aug 21, 2010 · Viewed 8.1k times · Source

In my app, I got a UINavigationController. Unfortunately, when I rotate the device and the interface orientation changes, the UINavigationBar doesn't change its height. In other iPhone applications, such as the Contacts.app, the navigation bar gets slightly less tall in landscape mode. It must be built-in, because if you take the navigation sample app from the XCode menu and add interface orientation to it, it does change the navigation bar's height properly.

How can I make the navigation bar resize like it does in all other iPhone apps I've seen?

Answer

Joost picture Joost · Aug 30, 2010

I've done a little testing, and although I don't like the method, it's quite easy to do.

Having looked for a private method that may have worked, I couldn't find one. All I found was:

@property BOOL forceFullHeightInLandscape;

- (BOOL)isMinibar;

There is no setter for -isMinibar, so we can't set that. I guess that it returns a value based on its height. Also, forceFullHeightInLandscape was set to NO, however it still didn't adjust its height.

While changing the autoresizingMask to include UIViewAutoresizingFlexibleHeight, the view did resize to be smaller, but now it was too small. However, -isMinibar suddenly returned YES. So that made me think of just letting the view resize itself, adjusting it to the right height.

So there we go, a method that works, even without private API calls:

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [self.navigationBar performSelector:@selector(sizeToFit) withObject:nil afterDelay:(0.5f * duration)];
}

One thing you'll have to deal with is that the views below the bar won't get adjusted to the smaller bar, so that there will be a gap between the bar and the views below. Easiest way to solve this is to add a container view, just like the case with a UINavigationController. You'd come up with something like:

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [self performSelector:@selector(resizeViewsForNavigationBar) withObject:nil afterDelay:(0.5f * duration)];
}

- (void)resizeViewsForNavigationBar {
    [self.navigationBar sizeToFit];

    // Resize containerView accordingly.
    CGRect containerViewRect = self.containerView.frame;
    containerViewRect.origin.y = CGRectGetMaxY(self.navigationBar.frame);
    containerViewRect.size.height = CGRectGetMaxY(self.view.frame) - containerViewRect.origin.y;
    self.containerView.frame = containerViewRect;
}