Is it possible to get textfield assosiated with a keyboard?

Question

In my view controller I'm subscribed to UIKeyboardWillShowNotification:

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

so in my keyboardWillShow: method I'm able to retrieve some info about the keyboard from the notification. But what I want is to get the reference to the actual text field which brings the keyboard up. I couldn't find how to do that in google and I suspect it might be impossible, but someone might know. If it is indeed impossible then I would like to know if there's a possibility to make it reverse way - to get the info about the keyboard by having the reference to the text field. Thanks

Answer 1

Let me emphasize that @iphonic comment is the right way to go.

You should use UITextField delegate function textFieldShouldBeginEditing:

Anything short of that is a kludge: UIKeyboardWillShowNotification assumes the software keyboard will show up, with is a very dangerous assumption and is likely to fail in all sorts of situations, starting with but not limited to Bluetooth keyboards. Try cmd-K in Simulator.

Here is aforementioned kludge, inspired by Get the current first responder without using a private API

func keyboardWillShow() {
    let firstResponder = self.findFirstResponder(inView: self.view)
    println("keyboardWillShow for \(firstResponder)")
}

func findFirstResponder(inView view: UIView) -> UIView? {
    for subView in view.subviews as! [UIView] {
        if subView.isFirstResponder() {
            return subView
        }

        if let recursiveSubView = self.findFirstResponder(inView: subView) {
            return recursiveSubView
        }
    }

    return nil
}