diff --git a/lib/app_component.dart b/lib/app_component.dart
index 4169c55..8e726df 100644
--- a/lib/app_component.dart
+++ b/lib/app_component.dart
@@ -39,22 +39,20 @@ class AppComponent implements OnInit {
   }
 
   void onStepClicked() {
-    engine.running = false;
-    engine.update();
+    engine.step();
   }
 
   void onResetClicked() {
-    engine.running = false;
     engine.reset();
   }
 
   void onRandomClicked() {
     engine.running = false;
-    engine.grid.addPattern();
+    engine.addPattern();
   }
 
   void onEdgesClicked() {
-    engine.grid.switchEdgeRendering();
+    engine.toggleEdgeRendering();
   }
 
   void onClearClicked() {
diff --git a/lib/src/Engine.dart b/lib/src/Engine.dart
index 04b4e95..80f16ed 100644
--- a/lib/src/Engine.dart
+++ b/lib/src/Engine.dart
@@ -19,20 +19,21 @@ class Engine {
   num _drawLag = 0.0;
 
   final html.CanvasElement canvas;
-  Grid grid = new Grid(100, 100);
-  bool running = false;
+  Grid _grid = new Grid(100, 100);
+  bool _running = false;
 
   Engine(this.canvas) {
     _elapsed.start();
-    grid.addPattern(amount: 15, dispersal: 5);
+    _grid.addPattern(amount: 15, dispersal: 5);
   }
 
   void reset() {
-    grid.reset();
+    _grid.reset();
+    running = false;
   }
 
   void clear() {
-    grid = new Grid(100, 100);
+    _grid = new Grid(100, 100);
     running = false;
   }
 
@@ -59,11 +60,34 @@ class Engine {
 
   void update() {
 //    print("updating");
-    if(!grid.update()) running = false;
+    if (!_grid.update()) running = false;
+  }
+
+  void step() {
+    running = false;
+    _grid.update();
   }
 
   void render([num interp]) {
 //    print("rendering");
-    grid.render(canvas, interp);
+    _grid.render(canvas, interp);
   }
+
+  void addPattern(
+      {CellPattern pattern, int x, int y, int amount, int dispersal, int seed}) {
+    _grid.addPattern(
+        pattern: pattern,
+        x: x,
+        y: y,
+        amount: amount,
+        dispersal: dispersal,
+        seed: seed);
+  }
+
+  void toggleEdgeRendering() {
+    _grid.renderEdges = !_grid.renderEdges;
+  }
+
+  void set running(bool on) => _running = on;
+  bool get running => _running;
 }
diff --git a/lib/src/Grid.dart b/lib/src/Grid.dart
index f47e5bf..528e170 100644
--- a/lib/src/Grid.dart
+++ b/lib/src/Grid.dart
@@ -208,8 +208,9 @@ class Grid {
     _dirty = false;
   }
 
-  void switchEdgeRendering([bool on]) {
-    _renderEdges = on ?? !_renderEdges;
+  void set renderEdges(bool on) {
+    _renderEdges = on;
     _dirty = true;
   }
+  bool get renderEdges => _renderEdges;
 }