Fix order of parent -> children rendering (#684)

* Fix order of parent -> children rendering

* Fix import

* Move debug rendering

* Call renderTree on children too

* Component to have renderTree

CHANGELOG.md

@@ -24,6 +24,7 @@
  - Added `toImage` method for the `Sprite` class
  - Uniform use of `dt` instead of `t` in all update methods
  - Add more optional arguments for unified constructors of components
+ - Fix order that parent -> children render in
 
 ## 1.0.0-rc6
  - Use `Offset` type directly in `JoystickAction.update` calculations

lib/src/components/base_component.dart

@@ -69,15 +69,22 @@ abstract class BaseComponent extends Component {
   @override
   void render(Canvas canvas) {
     prepareCanvas(canvas);
+  }
 
+  @mustCallSuper
+  @override
+  void renderTree(Canvas canvas) {
+    render(canvas);
+    _children.forEach((c) {
+      canvas.save();
+      c.renderTree(canvas);
+      canvas.restore();
+    });
+
+    // Any debug rendering should be rendered on top of everything
     if (debugMode) {
       renderDebugMode(canvas);
     }
-    _children.forEach((c) {
-      canvas.save();
-      c.render(canvas);
-      canvas.restore();
-    });
   }
 
   void renderDebugMode(Canvas canvas) {}

lib/src/components/component.dart

@@ -46,6 +46,10 @@ abstract class Component {
   /// Renders this component on the provided Canvas [c].
   void render(Canvas c) {}
 
+  /// This is used to render this component and potential children on subclasses
+  /// of [Component] on the provided Canvas [c].
+  void renderTree(Canvas c) => render(c);
+
   /// It receives the new game size.
   /// Executed right after the component is attached to a game and right before [onMount] is called
   void onGameResize(Vector2 gameSize) {}

lib/src/game/base_game.dart

@@ -4,6 +4,7 @@ import 'package:meta/meta.dart';
 import 'package:ordered_set/comparing.dart';
 import 'package:ordered_set/ordered_set.dart';
 
+import '../../components.dart';
 import '../components/component.dart';
 import '../components/mixins/collidable.dart';
 import '../components/mixins/draggable.dart';
@@ -131,7 +132,7 @@ class BaseGame extends Game with FPSCounter {
     if (!c.isHud) {
       canvas.translate(-camera.x, -camera.y);
     }
-    c.render(canvas);
+    c.renderTree(canvas);
     canvas.restore();
     canvas.save();
   }