Separate Engine Service Functionality from Component

lib/components/controls_component.dart

@@ -1,8 +1,6 @@
 import 'package:angular/angular.dart';
 import 'package:angular_components/angular_components.dart';
-import 'package:rules_of_living/service/configuration_service.dart';
 import 'package:rules_of_living/service/engine_service.dart';
-import 'package:rules_of_living/src/Engine.dart';
 
 @Component(
   selector: 'sim-controls',
@@ -17,13 +15,12 @@ import 'package:rules_of_living/src/Engine.dart';
   styleUrls: const ["controls_component.css"],
 )
 class ControlsComponent {
-  final EngineService engineService;
+  final EngineService engine;
 
-  Engine get engine => engineService.engine;
-  ControlsComponent(this.engineService);
+  ControlsComponent(this.engine);
 
   void onStartClicked() {
-    engine.running = !engine.running;
+    engine.toggleRunning();
   }
 
   void onStepClicked() {
@@ -35,8 +32,7 @@ class ControlsComponent {
   }
 
   void onRandomClicked() {
-    engine.running = false;
-    engine.addPattern();
+    engine.addRandomPattern();
   }
 
   void onClearClicked() {

lib/components/simulation_component.dart

@@ -8,7 +8,6 @@ import 'package:rules_of_living/service/engine_service.dart';
   templateUrl: "simulation_component.html",
   directives: [coreDirectives],
   providers: [],
-//  styleUrls: const ['package:angular_components/app_layout/layout.scss.css'],
 )
 class SimulationComponent implements OnInit {
   final EngineService engineService;
@@ -29,13 +28,6 @@ class SimulationComponent implements OnInit {
     If you see this\n
     the app is broken :(
     ''', canvas.width / 2 - 50, canvas.height / 2);
-    engineService.create(canvas);
-
-    html.window.animationFrame.then(animFrame);
-  }
-
-  void animFrame(num now) {
-    engineService.engine.process(now);
-    html.window.animationFrame.then(animFrame);
+//    engineService.create(canvas);
   }
 }

lib/service/engine_service.dart

@@ -5,7 +5,40 @@ import 'package:rules_of_living/src/Engine.dart';
 class EngineService {
   Engine _engine;
 
-  Engine get engine => _engine;
+  Engine get engine => _engine ?? create(null);
+
+  Engine create(html.CanvasElement canvas) {
+    _engine = Engine(canvas);
+    return _engine;
+  }
+
+  void run() {
+    engine.running = true;
+  }
+
+  void stop() {
+    engine.running = false;
+  }
+
+  void toggleRunning() {
+    engine.running = !engine.running;
+  }
+
+  void step() {
+    engine.step();
+  }
+
+  void reset() {
+    engine.reset();
+  }
+
+  void addRandomPattern() {
+    engine.running = false;
+    engine.addPattern();
+  }
+
+  void clear() {
+    engine.clear();
+  }
 
-  void create(html.CanvasElement canvas) => _engine = Engine(canvas);
 }

lib/src/Engine.dart

@@ -24,11 +24,17 @@ class Engine {
 
   final html.CanvasElement canvas;
   Grid _grid = new Grid(GRID_X, GRID_Y);
-  bool _running = false;
+  bool running = false;
 
   Engine([this.canvas]) {
     _elapsed.start();
     _grid.addPattern(amount: 15, dispersal: 5);
+    html.window.animationFrame.then(animFrame);
+  }
+
+  void animFrame(num now) {
+    process(now);
+    html.window.animationFrame.then(animFrame);
   }
 
   void reset() {
@@ -95,7 +101,4 @@ class Engine {
   void toggleEdgeRendering() {
     _grid.renderEdges = !_grid.renderEdges;
   }
-
-  void set running(bool on) => _running = on;
-  bool get running => _running;
 }