Disabling the Text Selection Magnifier on iOS

Based on the information provided, you're experiencing the iOS text selection magnifier appearing in your app after a double tap and hold gesture. This is a built-in iOS feature for text selection that was reintroduced in iOS 15.

While the CSS properties you've tried are a good start for preventing text selection, they don't completely disable the magnifier functionality. The magnifier is a system-level feature that's more deeply integrated with iOS.

Potential Solutions

1. Implement a custom gesture recognizer to intercept and handle the double-tap gesture before the system can use it for text selection:

SWIFTCopied
let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap(_:)))
doubleTapGesture.numberOfTapsRequired = 2
view.addGestureRecognizer(doubleTapGesture)

@objc func handleDoubleTap(_ gesture: UITapGestureRecognizer) {
    // Handle the double tap or simply consume it to prevent system handling
    // You can leave this empty if you just want to prevent the default behavior
}

2. For web-based content, ensure you're applying the CSS to all elements that might receive text selection events:

CSSCopied
* {
    -webkit-user-select: none;
    user-select: none;
    -webkit-touch-callout: none;
}

3. Disable interaction with text elements that aren't meant to be editable:

SWIFTCopied
textLabel.isUserInteractionEnabled = false

4. If using WKWebView, you can try injecting JavaScript to prevent text selection:

SWIFTCopied
let script = WKUserScript(source: "document.documentElement.style.webkitUserSelect='none';", injectionTime: .atDocumentEnd, forMainFrameOnly: true)
webView.configuration.userContentController.addUserScript(script)

5. For UITextView or other text components, consider implementing the delegate methods to intercept and prevent selection:

SWIFTCopied
func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
    return false // Prevents editing and selection
}

Since the magnifier is deeply integrated with iOS's text selection system, completely disabling it while maintaining all other touch functionality can be challenging. The most effective approach is usually to prevent the text selection from being triggered in the first place by properly handling gestures and configuring your UI elements.