📱✖️ Unity TouchScreenKeyboard “Support” Is a Lie (On Desktop WebGL)

When working with Nova UI’s scrollable input fields in Unity 6, we hit a frustrating issue: TouchScreenKeyboard.isSupported was returning true on desktop platforms like Windows and macOS.

But the virtual keyboard never showed. Why? Because Unity defines “support” loosely — if a hardware keyboard is available, it returns true, even though a soft keyboard is never displayed.

💥 The Symptom in NovaUI TextFieldMobileInput.InputLoop

if (touchScreenKeyboardController.Status != TouchScreenKeyboard.Status.Visible)

This check always failed — falsely assuming the keyboard was visible when it wasn’t, leading to unwanted focus loss or coroutine exits.

🧠 The Correct Fix

Don’t rely on TouchScreenKeyboard.isSupported alone. Combine it with Application.isMobilePlatform for a clean runtime check:

void Awake()
{
    if (!Application.isMobilePlatform)
    {
        Debug.Log("TextFieldMobileInput disabled on non-mobile platform.");
        this.enabled = false;
    }
}

Or if you want to patch the TextFieldMobileInput in NovaUI

protected override void OnEnable()
        {
            Debug.Log("TouchScreenKeyboard.isSupported: " + TouchScreenKeyboard.isSupported);
            if (!Application.isMobilePlatform || !TouchScreenKeyboard.isSupported)
            {
                Debug.Log("Disabling TextFieldMobileInput – not a mobile platform");
                enabled = false;
                // If touchscreen keyboard not supported on this device, do nothing
                return;
            }

            base.OnEnable();

            // Subscribe to selection changed so we can update the touch screen
            // keyboard whenever the input field selection changes
            inputField.OnTextSelectionChanged += UpdateTouchScreenKeyboardSelection;
        }

This avoids running mobile-only input code on platforms that don’t support it.

✅ Result

• On Android/iOS: TextFieldMobileInput handles soft keyboard input
• On desktop: TextFieldKeyboardInput takes over cleanly
• No misleading keyboard checks, no wasted coroutines

🧪 Bonus Tip

You can even enforce this in Editor via a context menu or validation script to ensure the prefab doesn’t re-enable this component accidentally during testing.

🧼 Final Thoughts

Unity’s platform quirks strike again — but with a one-line runtime guard, your Nova UI input fields can behave properly across platforms.