Scroll bug when presenting addCardViewController

[Klingefjord]

Summary

Scroll bug on addCardViewController. When textfield becomes first responder, the view scrolls autmoatically so that the card animation goes underneath the navigation bar

Code to reproduce

This is what I use to present the addCardViewController:

    func initializeStripe(_ sender: UIViewController, key: String) {
        let addCardViewController = STPAddCardViewController(configuration: StripeUtil.getPaymentConfiguration(key),
                                                             theme: StripeUtil.getTheme())
        addCardViewController.delegate = self
        sender.present(UINavigationController(rootViewController: addCardViewController), animated: true)
        }
    }

iOS version

11.3

Installation method

CocoaPods

SDK version

13.0.1

Other information

[joeydong-stripe]

Hi @Klingefjord, thanks for opening an issue and providing the gif.

This looks like the expected behavior as far as I know. The intended behavior is for the text field to be vertically center in the remaining space not taken up by the keyboard. As a result, the card can end up offscreen. What do you think?

Here is the code if you want to try experimenting with it:

https://github.com/stripe/stripe-ios/blob/master/Stripe/UIViewController%2BStripe_KeyboardAvoiding.m#L50-L60

One option is to stop calling stp_beginObservingKeyboardAndInsettingScrollView but that could become an issue in this particular case if the screen is shorter and the text field can end up behind the keyboard frame.

[Klingefjord]

Personally I think the textfield shouldn't get centered as it looks especially weird during the card flip animation. Maybe some tweaking to the offset if the textfield is the first one underneath the card? I tried changing https://github.com/stripe/stripe-ios/blob/master/Stripe/UIViewController%2BStripe_KeyboardAvoiding.m#L111 to offset.y = ((topOfScreenOffset + topOfKeyboardOffset) / 2) - scrollView.contentInset.top - 70;, It looks like the following on iPhone 5 and iPhone 7:

[joeydong-stripe]

Hi @Klingefjord

Thanks for taking a look, you were on the right track. We had a team discussion and decided to change our opinion and try to have the scroll view behave as natively as possible.

I just opened this pull request #943 and would love for you to try it out. As I mentioned in the pull request, we don't have too much context on how this class was implemented so we should invest extra time in testing the change.

[Klingefjord]

Great! Tested your pr out, think it looks much better.
Big thanks for quick response!

[joeydong-stripe]

👋 we just released v13.0.2 that includes this change. thanks for bringing it to our attention :)