Popover

Same as the previous project, except that the master view is relegated to a popover when the iPad is in portrait orientation. The detail view gets a UIToolBar with a “50 States” button in portrait orientation. The UIToolBar and its button disappear in landscape orientation.

Source code in Split.zip

1. main.m
2. Class SplitAppDelegate
3. Class MasterViewController
4. Class DetailViewController
5. Class DetailView

DetailView

The DetailViewController no longer controls the UIWebView directly. It now controls a DetailView, which contains two subviews: a UIToolBar and a UIWebView. The purpose of the UIToolBar is to hold the UIBarButtonItem (“50 States”) for summoning up the master view in a popover when the iPad is in landscape orientation.

The UIToolBar is visible only when the iPad is in portrait. When in landscape, it is rendered invisible by having its the height UIToolBar set to zero in the layoutSubviews method of the DetailView. (Setting the height to zero is simpler than removing the UIToolBar from its superview.) When in portrait, its height is restored.

The UIBarButtonItem is also removed from the UIToolBar when the iPad is in landscape. But this is total overkill because the UIToolBar is invisible. I just wanted to show you how to remove it.

The UISplitViewControllerDelegate

The DetailViewController is the object that most urgently needs to be informed when the orientation changes. It has to make the UIToolBar visible or invisible, and change the height of the UIWebView accordingly. We therefore let the DetailViewController be the delegate of the UISplitViewController.

The master view is not longer visible in portrait (unless we pop up the popover) because the UISplitViewController no longer has the method splitViewController:shouldHideViewController:inOrientation:.