add package files

com.htc.upm.vive.openxr/OpenXRHandTracking/Samples~/Scripts/ReadOnlyDrawer.cs

@@ -0,0 +1,28 @@
+using UnityEditor;
+using UnityEngine;
+
+namespace VIVE.HandTracking.Sample
+{
+    public class ReadOnlyAttribute : PropertyAttribute
+    {
+
+    }
+
+#if UNITY_EDITOR
+    [CustomPropertyDrawer(typeof(ReadOnlyAttribute))]
+    public class ReadOnlyDrawer : PropertyDrawer
+    {
+        public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
+        {
+            return EditorGUI.GetPropertyHeight(property, label, true);
+        }
+
+        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
+        {
+            GUI.enabled = false;
+            EditorGUI.PropertyField(position, property, label, true);
+            GUI.enabled = true;
+        }
+    }
+#endif
+}