motionpotion motionpotion - 1 year ago 573
iOS Question

unexpected nil window in _UIApplicationHandleEventFromQueueEvent, _windowServerHitTestWindow

I am trying to set up an edge swipe gesture in iOS 8 on iPad but getting and error that seems like a bug.

I have the following code:

UIScreenEdgePanGestureRecognizer *edgeRecognizer = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(handleRightEdgeSwipe:)];
edgeRecognizer.edges = UIRectEdgeRight;
[self.view addGestureRecognizer:edgeRecognizer];

and then I handle the gesture:

//slide in view code here

The problem is that it doesn't detect the right edge swipe every time. And sometimes it detects it multiple times.

Whether it detects or not it always shows the following information in the console when swiping the right edge on iPad:

2014-10-07 00:04:40.386 Office Log[1531:500896] unexpected nil window in _UIApplicationHandleEventFromQueueEvent, _windowServerHitTestWindow: ; layer = >

What does this message mean and how can I fix it so that the right edge swipe is detected consistently?

Answer Source

I think it's a bug in iOS, which I can confirm on an iPad mini 2 and an iPad Air on iOS 7 or higher, even on the Home Screen.

In "Landscape Left" (Home button on the left) a "Right Edge Gesture" from outside the Screen is not working for me. Test it by your self on the Home Screen.

I reported a bug to Apple 9 Month ago, but noting further happened.


I played a bit with the UIWindow init and when it is a bit bigger than it really is, the Gesture works. Of course this is a horrible fix.

self.window = [UIWindow new];
self.window.rootViewController = [[UIViewController alloc] init];

// Real Size
CGRect frame = [UIScreen mainScreen].bounds;

// Real Size + 0.000001
self.window.frame = CGRectMake(0, 0, frame.size.width+0.000001, frame.size.height+0.000001);
[self.window makeKeyAndVisible];
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