From 917eb805c6630a192f27ade90087e6f2e38abc24 Mon Sep 17 00:00:00 2001
From: "J. Neugebauer" <ngb@helmholtz-bi.de>
Date: Thu, 21 Jul 2022 21:01:33 +0200
Subject: [PATCH] Bug: Threadsafety

---
 src/main/java/schule/ngb/zm/layers/DrawableLayer.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/schule/ngb/zm/layers/DrawableLayer.java b/src/main/java/schule/ngb/zm/layers/DrawableLayer.java
index 14fe775..f04db05 100644
--- a/src/main/java/schule/ngb/zm/layers/DrawableLayer.java
+++ b/src/main/java/schule/ngb/zm/layers/DrawableLayer.java
@@ -48,7 +48,7 @@ public class DrawableLayer extends Layer {
 		}
 
 		synchronized( drawables ) {
-			List<Drawable> it = Collections.unmodifiableList(drawables);
+			List<Drawable> it = List.copyOf(drawables);
 			for( Drawable d : it ) {
 				if( d.isVisible() ) {
 					d.draw(drawing);