Get the current first responder without using a private API
cocoa-touch, first-responder, objective-c
Solution
In one of my applications I often want the first responder to resign if the user taps on the background. For this purpose I wrote a category on UIView, which I call on the UIWindow.
The following is based on that and should return the first responder.
@implementation UIView (FindFirstResponder)
- (id)findFirstResponder
{
if (self.isFirstResponder) {
return self;
}
for (UIView *subView in self.subviews) {
id responder = [subView findFirstResponder];
if (responder) return responder;
}
return nil;
}
@end
iOS 7+
- (id)findFirstResponder
{
if (self.isFirstResponder) {
return self;
}
for (UIView *subView in self.view.subviews) {
if ([subView isFirstResponder]) {
return subView;
}
}
return nil;
}
Swift:
extension UIView {
var firstResponder: UIView? {
guard !isFirstResponder else { return self }
for subview in subviews {
if let firstResponder = subview.firstResponder {
return firstResponder
}
}
return nil
}
}
Usage example in Swift:
if let firstResponder = view.window?.firstResponder {
// do something with `firstResponder`
}
Problem
I submitted my app a little over a week ago and got the dreaded rejection email today. It tells me that my app cannot be accepted because I'm using a non-public API; specifically, it says, The non-public API that is included in your application is firstResponder. Now, the offending API call is actually a solution I found here on SO: ``` UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow]; UIView *firstResponder = [keyWindow performSelector:@selector(firstResponder)]; ``` How do I get the current first responder on the screen? I'm looking for a way that won't get my app rejected.