Get the current first responder without using a private API

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`
}