How to debug who is eating my touches in UIKit?

Question

I can\'t figure out why tapping on text fields and buttons in my view is not working. I\'ve checked all the obvious things like whether userInteractionEnabled is set to YES, whe

Answer 1

You can subclass UIWindow and override -[UIWindow sendEvent]:, then when it is called, use -[UIWindow hitTest:withEvent:] to test which view will receive the event.

You can then call -[UIView recursiveDescription] to print some debug information help you understand why that view received the touch event.

Remember to call [super sendEvent:] when you are done.

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For those who use Storyboard and want to know how can we change the main application window class:

class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow? = TestWindow()
    // ....
}

Just provide the default value for AppDelegate's window var. When the app is launched the UIApplicationMain will instantiate a delegate and ask it for the window. If the window is nil it will create a new one automatically. But if we provide a default value here, it will be used all over the app.