From 6b7e8edb28bab6495fbc75c11be0805949811dfe Mon Sep 17 00:00:00 2001
From: Marty Oehme <marty.oehme@gmail.com>
Date: Fri, 6 Jul 2018 16:46:30 +0200
Subject: [PATCH] Fix Cell Propagation through intermediate Step

the next targeted state is first propagated to all Cells, then they all adopt their new states at once.
---
 lib/Cell.dart | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/Cell.dart b/lib/Cell.dart
index 5528492..d9344ff 100644
--- a/lib/Cell.dart
+++ b/lib/Cell.dart
@@ -2,22 +2,26 @@ import 'package:rules_of_living/Rule.dart';
 
 class Cell {
   bool state;
+  bool nextState = false;
   List<Rule> surviveRules = new List<Rule>();
   List<Rule> birthRules = new List<Rule>();
 
   Cell([bool state = false]) : this.state = state;
 
+  void advanceState() {
+    this.state = this.nextState;
+    this.nextState = false;
+  }
+
   void update(int neighbors) {
-    bool newState = false;
     if (state == true) {
       surviveRules.forEach( (Rule rule) {
-        if(rule.evaluate(neighbors) == true) newState = true;
+        if(rule.evaluate(neighbors) == true) this.nextState = true;
       });
     } else {
       birthRules.forEach((Rule rule) {
-        if (rule.evaluate(neighbors) == true) newState = true;
+        if (rule.evaluate(neighbors) == true) this.nextState = true;
       });
     }
-    this.state = newState;
   }
 }