upd

src/Ryujinx/UI/Helpers/OffscreenTextBox.cs

@@ -0,0 +1,42 @@
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using System;
+
+namespace Ryujinx.Ava.UI.Helpers
+{
+    public class OffscreenTextBox : TextBox
+    {
+        protected override Type StyleKeyOverride => typeof(TextBox);
+
+        public static RoutedEvent<KeyEventArgs> GetKeyDownRoutedEvent()
+        {
+            return KeyDownEvent;
+        }
+
+        public static RoutedEvent<KeyEventArgs> GetKeyUpRoutedEvent()
+        {
+            return KeyUpEvent;
+        }
+
+        public void SendKeyDownEvent(KeyEventArgs keyEvent)
+        {
+            OnKeyDown(keyEvent);
+        }
+
+        public void SendKeyUpEvent(KeyEventArgs keyEvent)
+        {
+            OnKeyUp(keyEvent);
+        }
+
+        public void SendText(string text)
+        {
+            OnTextInput(new TextInputEventArgs
+            {
+                Text = text,
+                Source = this,
+                RoutedEvent = TextInputEvent,
+            });
+        }
+    }
+}