Justin Kredible Justin Kredible - 6 months ago 42
Objective-C Question

Get the current first responder without using a private API

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.

Answer

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;
}