SetFocusOnTappedBehavior.cs

using System.ComponentModel;
 
namespace NeuroAccessMaui.UI.Behaviors
{
    public class SetFocusOnTappedBehavior : Behavior<View>
    {
        [TypeConverter(typeof(ReferenceTypeConverter))]
        public View? SetFocusTo { get; set; }
 
        protected override void OnAttachedTo(View View)
        {
            TapGestureRecognizer Tap = new();
            View.GestureRecognizers.Add(Tap);
            Tap.Tapped += this.Tap_Tapped;
 
            base.OnAttachedTo(View);
        }
 
        protected override void OnDetachingFrom(View View)
        {
            foreach (IGestureRecognizer Gesture in View.GestureRecognizers)
            {
                if (Gesture is TapGestureRecognizer Tap)
                {
                    Tap.Tapped -= this.Tap_Tapped;
                    View.GestureRecognizers.Remove(Tap);
                    break;
                }
            }
 
            base.OnDetachingFrom(View);
        }
 
        private void Tap_Tapped(object? Sender, EventArgs e)
        {
            FocusOn(this.SetFocusTo);
        }
 
        public static void FocusOn(View? Element)
        {
            if (Element is not null && Element.IsVisible)
            {
                Element.Focus();
 
                if (Element is Entry Entry && Entry.Text is not null)
                    Entry.CursorPosition = Entry.Text.Length;
            }
        }
    }
}