UnityUiExtensions.cs

public class UnityUiExtensions {

  /// <summary>
  /// Check if the mouse or first finger is over Unity UI element.
  /// </summary>
  /// <returns></returns>
  private bool IsOverUi() {
#if (UNITY_ANDROID || UNITY_IOS) && !UNITY_EDITOR
    return EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId);
#else
    return EventSystem.current.IsPointerOverGameObject();
#endif
  }
}