iOS: add support for TextInputType.none

[jpnurmi]

TextInputType.none makes it possible to disable the virtual keyboard for certain TextFields, and lays the foundations for custom in-app virtual keyboards (flutter/flutter#76072).

Ref: flutter/flutter#83567

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[jpnurmi]

Minimal example: https://github.com/jpnurmi/text_input_type_none_example (requires flutter/flutter#83974 for the enum value)

Simulator.Screen.Recording.-.iPhone.12.-.2021-06-15.at.23.30.27.mp4

[LongCatIsLooong]

Thanks for the PR! Could you add tests to verify isKeyboardEnabled works correctly?

[LongCatIsLooong]

looking at the hideTextInput's implementation it removes the active view from the view hierarchy and disables accessibility. Will this break voiceover? @chunhtai

[chunhtai]

yes it will, we may need to find a better way to prevent softkeyboard from showing up. whichever the method we found here, we need to make sure the key stroke feedback in voice over still works

[LongCatIsLooong]

You might be able to use an empty UIView for inputView according to the documentation.

[LongCatIsLooong]

And there's an inputViewController property as well: https://developer.apple.com/documentation/uikit/uiresponder/1621117-inputviewcontroller?language=objc

[jpnurmi]

Would either of you have a chance to give it a shot, or is there anyone else that might have time to help?

[LongCatIsLooong]

Currently dealing with something else. I'll give that a try later.

[LongCatIsLooong]

inputView didn't work as advertised for me, but inputViewController did. I overrode inputViewController like so :

  let inputVC = UIInputViewController()
  override var inputViewController: UIInputViewController? {
    shouldShowKeyboard ? nil : inputVC
  }

You get the system keyboard when returning nil for inputViewController, and a UIIpnutViewController gives a zero-width keyboard view.

[jpnurmi]

Great! Mind pushing the patch? I'll close this because I'm no iOS dev... 🙂

[jpnurmi]

Thank you for trying it out!