If you want to understand SpringBoard's view hierarchy:
- Launch the iOS Simulator if it's not already running.
- Make sure you're looking at SpringBoard in the simulator.
- In Xcode, choose Product > Attach to Process > springboard. The springboard process is way down in the “System” section of the list.
- Still in Xcode, choose Product > Debug > Pause.
- In Xcode's debug console (where it should show the
(lldb)
prompt), typepo [[UIApp keyWindow] recursiveDescription]
.
Voila, you get a printout of SpringBoard's entire on-screen view hierarchy. Mine starts out like this:
(lldb) po [[UIApp keyWindow] recursiveDescription]
$0 = 0x0b63abf0 <SBAppWindow: 0xce3ef10; baseClass = UIWindow; frame = (0 0; 320 480); layer = <UIWindowLayer: 0xce3f010>>
| <SBUIRootView: 0xb162de0; frame = (0 0; 320 480); layer = <CALayer: 0xb162e60>>
| | <UIView: 0xb163010; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0xb1630c0>>
| | | <SBWallpaperView: 0xb1632a0; baseClass = UIImageView; frame = (0 0; 320 480); userInteractionEnabled = NO; layer = <CALayer: 0xb160f70>>
| | | | <UIImageView: 0xb1610d0; frame = (0 0; 0 0); hidden = YES; userInteractionEnabled = NO; layer = <CALayer: 0xb161130>>
| | | | <UIImageView: 0xb161160; frame = (0 0; 0 0); hidden = YES; userInteractionEnabled = NO; layer = <CALayer: 0xb163390>>
| | | <SBIconContentView: 0xb163da0; frame = (0 0; 320 480); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0xb163e50>>
| | | | <UIView: 0xc939710; frame = (0 371; 320 109); opaque = NO; autoresize = W+TM; layer = <CALayer: 0xc939770>>
| | | | | <SBDockIconListView: 0xc9381d0; frame = (0 20; 320 89); autoresize = TM; layer = <CALayer: 0xc9382c0>>
...