UITextView using TextKit 1

14 Jul, 2024

I received this warning and was surprised to know that there are 2 TextKits, TextKit 1 and 2 in the iOS SDK.

UITextView 0x1063c9000 is switching to TextKit 1 compatibility mode because its layoutManager was accessed. Break on void _UITextViewEnablingCompatibilityMode(UITextView *__strong, BOOL) to debug.

I use UITextView’s LayoutManager so I can detect the text or a group of texts that the user has tapped or selected.

func textViewDidChangeSelection(_ textView: UITextView) {
	textView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(textTapped(_:))))
}

@objc private func textTapped(_ sender: UITapGestureRecognizer) {
	let textView = sender.view as! CustomTextView
	let layoutManger = textView.layoutManager
	// Location of the tap
	var location = sender.location(in: textView)
	location.x -= textView.textContainerInset.left
	location.y -= textView.textContainerInset.top
	// Character index at tap location
	let characterIndex = layoutManger.characterIndex(for: location, in: textView.textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
}

So based on the answer on the question Replacing layout manager in UITextView using TextKit 1, I need to override NSLayoutManager.

class CustomTextView: UITextView {

	private var customLayoutManager = NSLayoutManager()

	init(someData: String) {
        self.someData = someData
        super.init(frame: .zero, textContainer: nil)
        customLayoutManager.textStorage = self.textStorage
        customLayoutManager.addTextContainer(self.textContainer)
        self.textContainer.replaceLayoutManager(customLayoutManager)
    }

	override var layoutManager: NSLayoutManager {
        return customLayoutManager
    }
}