throw exception when invalid enum value (should be applied to all enums)

haxe/ui/constants/ScrollMode.hx

@@ -1,7 +1,27 @@
 package haxe.ui.constants;
 
-enum abstract ScrollMode(String) from String to String {
-    var NORMAL = "normal";
-    var DRAG = "drag";
-    var INERTIAL = "inertial";
-}
+import haxe.ui.util.Variant;
+
+enum abstract ScrollMode(String) to String {
+	var NORMAL = "normal";
+	var DRAG = "drag";
+	var INERTIAL = "inertial";
+	var HYBRID = "hybrid";
+
+	@:from public static function fromString(s:String):ScrollMode {
+		return switch (s.toLowerCase()) {
+			case "normal":      NORMAL;
+			case "drag":        DRAG;
+			case "inertial":    INERTIAL;
+			case "hybrid":      HYBRID;
+			case _: throw "invalid ScrollMode enum value '" + s + "'";
+		}
+	}
+
+    @:from public static function fromVariant(v:Variant):ScrollMode {
+        if (v == null || v.isNull) {
+            return null;
+        }
+        return fromString(v.toString());
+    }
+}