what if we leave ongui only in the base class

Author: K-Tone

Packages/com.unity.inputsystem/InputSystem/Editor/InputParameterEditor.cs

@@ -27,6 +27,13 @@ public abstract class InputParameterEditor
         /// </summary>
         public object target { get; internal set; }
 
+        /// <summary>
+        /// Callback for implementing a custom UI.
+        /// It was mostly needed for the imgui-based editors and should be avoided now.
+        /// Should be removed once we can release the next major version.
+        /// </summary>
+        public void OnGUI() { }
+
         /// <summary>
         /// Add visual elements for this parameter editor to a root VisualElement.
         /// </summary>