Refactors code in demo game to make it simpler

examples/game/lib/game_object_factory.dart

 part of game;
 
-enum GameObjectType {
-  asteroidBig,
-  asteroidSmall,
-  asteroidPowerUp,
-  enemyScout,
-  enemyDestroyer,
-  coin,
-}
-
 class GameObjectFactory {
   GameObjectFactory(this.sheet, this.sounds, this.level, this.playerState);
 
@@ -19,11 +10,17 @@ class GameObjectFactory {
 
   void addAsteroids(int numAsteroids, double yPos, double distribution) {
     for (int i = 0; i < numAsteroids; i++) {
-      GameObjectType type = (randomDouble() < distribution) ? GameObjectType.asteroidBig : GameObjectType.asteroidSmall;
-      if (i == 0) type = GameObjectType.asteroidPowerUp;
+      GameObject obj;
+      if (i == 0)
+        obj = new AsteroidPowerUp(this);
+      else if (randomDouble() < distribution)
+        obj = new AsteroidBig(this);
+      else
+        obj = new AsteroidSmall(this);
+
       Point pos = new Point(randomSignedDouble() * 160.0,
                             yPos + _chunkSpacing * randomDouble());
-      addGameObject(type, pos);
+      addGameObject(obj, pos);
     }
   }
 
@@ -31,31 +28,17 @@ class GameObjectFactory {
     for (int i = 0; i < numEnemies; i++) {
       double spacing = math.max(_chunkSpacing / (numEnemies + 1.0), 80.0);
       double y = yPos + _chunkSpacing / 2.0 - (numEnemies - 1) * spacing / 2.0 + i * spacing;
-      addGameObject(GameObjectType.enemyScout, new Point(0.0, y));
+      addGameObject(new EnemyScout(this), new Point(0.0, y));
     }
   }
 
   void addEnemyDestroyerSwarm(int numEnemies, double yPos) {
     for (int i = 0; i < numEnemies; i++) {
-      addGameObject(GameObjectType.enemyDestroyer, new Point(randomSignedDouble() * 120.0 , yPos + _chunkSpacing * randomDouble()));
+      addGameObject(new EnemyDestroyer(this), new Point(randomSignedDouble() * 120.0 , yPos + _chunkSpacing * randomDouble()));
     }
   }
 
-  void addGameObject(GameObjectType type, Point pos) {
-    GameObject obj;
-    if (type == GameObjectType.asteroidBig)
-      obj = new AsteroidBig(this);
-    else if (type == GameObjectType.asteroidSmall)
-      obj = new AsteroidSmall(this);
-    else if (type == GameObjectType.asteroidPowerUp)
-      obj = new AsteroidPowerUp(this);
-    else if (type == GameObjectType.enemyScout)
-      obj = new EnemyScout(this);
-    else if (type == GameObjectType.enemyDestroyer)
-      obj = new EnemyDestroyer(this);
-    else if (type == GameObjectType.coin)
-      obj = new Coin(this);
-
+  void addGameObject(GameObject obj, Point pos) {
     obj.position = pos;
     obj.setupActions();
 
@@ -64,10 +47,10 @@ class GameObjectFactory {
 
   void addBossFight(int l, double yPos) {
     EnemyBoss boss = new EnemyBoss(this);
-    boss.position = new Point(0.0, yPos + _chunkSpacing / 2.0);
-    boss.setupActions();
+    Point pos = new Point(0.0, yPos + _chunkSpacing / 2.0);
+
+    addGameObject(boss, pos);
 
-    level.addChild(boss);
     playerState.boss = boss;
   }
 }

examples/game/lib/game_objects.dart

@@ -44,9 +44,7 @@ abstract class GameObject extends Node {
 
       Collectable powerUp = createPowerUp();
       if (powerUp != null) {
-        powerUp.position = position;
-        powerUp.setupActions();
-        parent.addChild(powerUp);
+        f.addGameObject(powerUp, position);
       }
 
       removeFromParent();