From the iOS Human Interface Guidelines, iOS UI Element Usage Guidelines
On iPhone, take into account the automatic change in toolbar height that occurs on device rotation. In particular, make sure your custom toolbar icons fit well in the thinner bar that appears in landscape orientation. Don’t specify the height of a toolbar programmatically.
I can see the height changing from 44 points to 32 points in Mail, Twitter for iPhone and Dropbox for example, but when I add a toolbar (with Interface Builder) and have my UIViewController subclass to automatically rotate (shouldAutorotateToInterfaceOrientation:
returns YES), the toolbar does not automatically change its height on device rotation.
The UIToolbar Class Reference does not mention this automatic change of height, so am I supposed to change it programmatically even though the HIG says Don’t specify the height of a toolbar programmatically?