Mysterious crash when presenting a view controller using a custom UIPresentationController subclass

Question

I'm experiencing a crash on iOS 8.1 (device and simulator) when attempting to do a custom presention a UIViewController with a custom UIPresentationController subclass.

The exception raised prints the following to the console:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSSetM addObject:]: object cannot be nil'
*** First throw call stack:
(
    0   CoreFoundation                      0x03bc9946 __exceptionPreprocess + 182
    1   libobjc.A.dylib                     0x03479a97 objc_exception_throw + 44
    2   CoreFoundation                      0x03ae018b -[__NSSetM addObject:] + 699
    3   UIKit                               0x023bf389 -[UIPeripheralHost(UIKitInternal) _beginPinningInputViewsOnBehalfOfResponder:] + 50
    4   UIKit                               0x01f81188 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 2306
    5   UIKit                               0x01fb47ab __40+[UIViewController _scheduleTransition:]_block_invoke + 18
    6   UIKit                               0x01e7a0ce ___afterCACommitHandler_block_invoke + 15
    7   UIKit                               0x01e7a079 _applyBlockToCFArrayCopiedToStack + 415
    8   UIKit                               0x01e79e8e _afterCACommitHandler + 545
    9   CoreFoundation                      0x03aec9de __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
    10  CoreFoundation                      0x03aec920 __CFRunLoopDoObservers + 400
    11  CoreFoundation                      0x03ae235a __CFRunLoopRun + 1226
    12  CoreFoundation                      0x03ae1bcb CFRunLoopRunSpecific + 443
    13  CoreFoundation                      0x03ae19fb CFRunLoopRunInMode + 123
    14  GraphicsServices                    0x052fb24f GSEventRunModal + 192
    15  GraphicsServices                    0x052fb08c GSEventRun + 104
    16  UIKit                               0x01e508b6 UIApplicationMain + 1526
    17  Spruce Dr                           0x001015ad main + 141
    18  libdyld.dylib                       0x04e6eac9 start + 1
)

Here's where I vent the UIPresentationController:

- (UIPresentationController *)presentationControllerForPresentedViewController:(UIViewController *)presented presentingViewController:(UIViewController *)presenting sourceViewController:(UIViewController *)source
{
    return [[STKBlurredBackgroundContentPresentationController alloc] init];
}

Freeswimming

Answer 1

UIPresentationController's designated initializer must be used:

- (UIPresentationController *)presentationControllerForPresentedViewController:(UIViewController *)presented presentingViewController:(UIViewController *)presenting sourceViewController:(UIViewController *)source
{
    return [[STKBlurredBackgroundContentPresentationController alloc] initWithPresentedViewController:presented presentingViewController:presenting];
}

Note: I'm answering my own question here in case anyone else makes the same mistake in the future. In retrospect, it's quite clear why using the designated initializer must be utilized.

Freeswimming

UIKit should check this earlier, and it also does not follow the designated initialiser pattern — openradar.appspot.com/22269465 – Doud

it was the same issue, in my initWithPresented.. when calling super initialiser i was calling only [super init] it should be [super initWithPresented..] – Bekki