bunnyhero dev » UIKit http://www.bunnyhero.org Notes on iPhone, Flash and Web development Fri, 23 Jul 2010 18:00:10 +0000 en hourly 1 http://wordpress.org/?v=3.0 UITabBarController timing change from OS 2.X to 3.0 http://www.bunnyhero.org/2009/06/29/uitabbarcontroller-timing-change/ http://www.bunnyhero.org/2009/06/29/uitabbarcontroller-timing-change/#comments Mon, 29 Jun 2009 21:58:50 +0000 bunnyhero http://www.bunnyhero.org/?p=207 This is just a short note about a change I discovered between iPhone OS 2.x and 3.0. It’s not very interesting or exciting but I thought I’d record it in the off chance that it helps someone else.

When the user switches tabs on a UITabBarController in iPhone OS 2.x, the sequence of events is:

  1. UIView of new tab gets added as a subview
  2. UIView of old tab gets removed
  3. The delegate’s tabBarController:didSelectViewController: method is called

Run the same code on iPhone OS 3.0, however, and the sequence is this:

  1. UIView of new tab gets added as a subview
  2. The delegate’s tabBarController:didSelectViewController: method is called
  3. UIView of old tab gets removed (sometime later, I think it’s invoked via one of NSObject‘s performSelector: methods)

This is a inconsequential change for most, but it might make a difference if you are checking the UIViews’ superview variables in your tab bar controller delegate method.

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