Adding images on Game, auto clear on game detach, fixing some examples

doc/examples/debug/lib/main.dart

@@ -5,14 +5,16 @@ import 'package:flame/components/sprite_component.dart';
 import 'package:flame/components/mixins/resizable.dart';
 import 'package:flame/text_config.dart';
 
-import 'package:flutter/material.dart';
+import 'package:flutter/material.dart' hide Image;
+
+import 'dart:ui';
 
 void main() async {
+  Flame.initializeWidget();
   await Flame.util.initialDimensions();
 
   final myGame = MyGame();
   runApp(myGame.widget);
-  myGame.start();
 }
 
 class AndroidComponent extends SpriteComponent with Resizable {
@@ -20,7 +22,7 @@ class AndroidComponent extends SpriteComponent with Resizable {
   int xDirection = 1;
   int yDirection = 1;
 
-  AndroidComponent() : super.square(100, 'android.png');
+  AndroidComponent(Image image) : super.square(100, image);
 
   @override
   void update(double dt) {
@@ -56,17 +58,20 @@ class MyGame extends BaseGame {
   @override
   bool recordFps() => true;
 
-  void start() {
-    final android = AndroidComponent();
+  @override
+  Future<void> onLoad() async {
+    final androidImage = await images.load('android.png');
+
+    final android = AndroidComponent(androidImage);
     android.x = 100;
     android.y = 400;
 
-    final android2 = AndroidComponent();
+    final android2 = AndroidComponent(androidImage);
     android2.x = 100;
     android2.y = 400;
     android2.yDirection = -1;
 
-    final android3 = AndroidComponent();
+    final android3 = AndroidComponent(androidImage);
     android3.x = 100;
     android3.y = 400;
     android3.xDirection = -1;

doc/examples/layers/lib/main.dart

@@ -7,15 +7,11 @@ import 'package:flame/flame.dart';
 import 'dart:ui';
 
 void main() async {
-  WidgetsFlutterBinding.ensureInitialized();
+  Flame.initializeWidget();
 
   await Flame.util.fullScreen();
 
-  final playerSprite = await Sprite.loadSprite('player.png');
-  final enemySprite = await Sprite.loadSprite('enemy.png');
-  final backgroundSprite = await Sprite.loadSprite('background.png');
-
-  runApp(LayerGame(playerSprite, enemySprite, backgroundSprite).widget);
+  runApp(LayerGame().widget);
 }
 
 class GameLayer extends DynamicLayer {
@@ -56,14 +52,15 @@ class BackgroundLayer extends PreRenderedLayer {
 }
 
 class LayerGame extends Game {
-  Sprite playerSprite;
-  Sprite enemySprite;
-  Sprite backgroundSprite;
-
   Layer gameLayer;
   Layer backgroundLayer;
 
-  LayerGame(this.playerSprite, this.enemySprite, this.backgroundSprite) {
+  @override
+  Future<void> onLoad() async {
+    final playerSprite = Sprite(await images.load('player.png'));
+    final enemySprite = Sprite(await images.load('enemy.png'));
+    final backgroundSprite = Sprite(await images.load('background.png'));
+
     gameLayer = GameLayer(playerSprite, enemySprite);
     backgroundLayer = BackgroundLayer(backgroundSprite);
   }

doc/examples/nine_tile_box/lib/main.dart

@@ -17,8 +17,11 @@ class MyGame extends Game {
   Size size;
   NineTileBox nineTileBox;
 
-  MyGame(this.size) {
-    final sprite = Sprite('nine-box.png');
+  MyGame(this.size);
+
+  @override
+  Future<void> onLoad() async {
+    final sprite = Sprite(await images.load('nine-box.png'));
     nineTileBox = NineTileBox(sprite, tileSize: 8, destTileSize: 24);
   }
 

doc/examples/particles/lib/main.dart

@@ -65,6 +65,12 @@ class MyGame extends BaseGame {
     Timer.periodic(sceneDuration, (_) => spawnParticles());
   }
 
+  @override
+  Future<void> onLoad() async {
+    await images.load('zap.png');
+    await images.load('boom3.png');
+  }
+
   /// Showcases various different uses of [Particle]
   /// and its derivatives
   void spawnParticles() {
@@ -295,7 +301,7 @@ class MyGame extends BaseGame {
   Particle imageParticle() {
     return ImageParticle(
       size: const Size.square(24),
-      image: Flame.images.loadedFiles['zap.png'].loadedImage,
+      image: images.fromCache('zap.png'),
     );
   }
 
@@ -385,7 +391,7 @@ class MyGame extends BaseGame {
   /// Flame's [Sprite] into the effect.
   Particle spriteParticle() {
     return SpriteParticle(
-      sprite: Sprite('zap.png'),
+      sprite: Sprite(images.fromCache('zap.png')),
       size: Position.fromOffset(cellSize * .5),
     );
   }
@@ -524,12 +530,11 @@ class MyGame extends BaseGame {
     const columns = 8;
     const rows = 8;
     const frames = columns * rows;
-    const imagePath = 'boom3.png';
-    final spriteImage = Flame.images.loadedFiles[imagePath].loadedImage;
+    final spriteImage = images.fromCache('boom3.png');
     final spritesheet = SpriteSheet(
       rows: rows,
       columns: columns,
-      imageName: imagePath,
+      image: spriteImage,
       textureWidth: spriteImage.width ~/ columns,
       textureHeight: spriteImage.height ~/ rows,
     );
@@ -543,19 +548,8 @@ class MyGame extends BaseGame {
 }
 
 Future<BaseGame> loadGame() async {
-  Size gameSize;
-  WidgetsFlutterBinding.ensureInitialized();
-
-  await Future.wait([
-    Flame.util.initialDimensions().then((size) => gameSize = size),
-    Flame.images.loadAll(const [
-      'zap.png',
-
-      /// Credits to Stumpy Strust from
-      /// https://opengameart.org/content/explosion-sheet
-      'boom3.png',
-    ]),
-  ]);
+  Flame.initializeWidget();
+  final gameSize = await Flame.util.initialDimensions();
 
   return MyGame(screenSize: gameSize);
 }

lib/assets/images.dart

@@ -6,14 +6,21 @@ import 'dart:convert' show base64;
 import 'package:flame/flame.dart';
 
 class Images {
-  Map<String, ImageAssetLoader> loadedFiles = {};
+  final Map<String, _ImageAssetLoader> _loadedFiles = {};
 
   void clear(String fileName) {
-    loadedFiles.remove(fileName);
+    _loadedFiles.remove(fileName);
   }
 
   void clearCache() {
-    loadedFiles.clear();
+    _loadedFiles.clear();
+  }
+
+  Image fromCache(String fileName) {
+    final image = _loadedFiles[fileName];
+    assert(image?.loadedImage != null,
+        'Tried to access an inexistent entry on cache "$fileName"');
+    return image.loadedImage;
   }
 
   Future<List<Image>> loadAll(List<String> fileNames) async {
@@ -21,17 +28,17 @@ class Images {
   }
 
   Future<Image> load(String fileName) async {
-    if (!loadedFiles.containsKey(fileName)) {
-      loadedFiles[fileName] = ImageAssetLoader(_fetchToMemory(fileName));
+    if (!_loadedFiles.containsKey(fileName)) {
+      _loadedFiles[fileName] = _ImageAssetLoader(_fetchToMemory(fileName));
     }
-    return await loadedFiles[fileName].retreive();
+    return await _loadedFiles[fileName].retreive();
   }
 
   Future<Image> fromBase64(String fileName, String base64) async {
-    if (!loadedFiles.containsKey(fileName)) {
-      loadedFiles[fileName] = ImageAssetLoader(_fetchFromBase64(base64));
+    if (!_loadedFiles.containsKey(fileName)) {
+      _loadedFiles[fileName] = _ImageAssetLoader(_fetchFromBase64(base64));
     }
-    return await loadedFiles[fileName].retreive();
+    return await _loadedFiles[fileName].retreive();
   }
 
   Future<Image> _fetchFromBase64(String base64Data) async {
@@ -53,8 +60,8 @@ class Images {
   }
 }
 
-class ImageAssetLoader {
-  ImageAssetLoader(this.future);
+class _ImageAssetLoader {
+  _ImageAssetLoader(this.future);
 
   Image loadedImage;
   Future<Image> future;

lib/flame.dart

@@ -6,7 +6,7 @@ import 'package:flutter/widgets.dart';
 
 import 'flame_audio.dart';
 import 'bgm.dart';
-import 'images.dart';
+import 'assets/images.dart';
 import 'assets_cache.dart';
 import 'util.dart';
 

lib/game/game.dart

@@ -7,10 +7,11 @@ import 'package:flutter/widgets.dart' hide WidgetBuilder;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 
-import '../keyboard.dart';
-
 import 'widget_builder.dart';
 
+import '../keyboard.dart';
+import '../assets/images.dart';
+
 /// Represents a generic game.
 ///
 /// Subclass this to implement the [update] and [render] methods.
@@ -19,6 +20,8 @@ abstract class Game {
   // Widget Builder for this Game
   final builder = WidgetBuilder();
 
+  final images = Images();
+
   /// Returns the game background color.
   /// By default it will return a black color.
   /// It cannot be changed at runtime, because the game widget does not get rebuild when this value changes.
@@ -78,6 +81,8 @@ abstract class Game {
     if (this is KeyboardEvents) {
       RawKeyboard.instance.removeListener(_handleKeyEvent);
     }
+
+    images.clearCache();
   }
 
   /// Flag to tell the game loop if it should start running upon creation

lib/spritesheet.dart

@@ -14,38 +14,6 @@ class SpriteSheet {
   List<List<Sprite>> _sprites;
 
   SpriteSheet({
-    @required String imageName,
-    @required this.textureWidth,
-    @required this.textureHeight,
-    @required this.columns,
-    @required this.rows,
-  }) {
-    _sprites = List.generate(
-      rows,
-      (y) => List.generate(
-        columns,
-        (x) => _mapImagePath(imageName, textureWidth, textureHeight, x, y),
-      ),
-    );
-  }
-
-  Sprite _mapImagePath(
-    String imageName,
-    int textureWidth,
-    int textureHeight,
-    int x,
-    int y,
-  ) {
-    return Sprite(
-      imageName,
-      x: (x * textureWidth).toDouble(),
-      y: (y * textureHeight).toDouble(),
-      width: textureWidth.toDouble(),
-      height: textureHeight.toDouble(),
-    );
-  }
-
-  SpriteSheet.fromImage({
     @required Image image,
     @required this.textureWidth,
     @required this.textureHeight,
@@ -56,19 +24,19 @@ class SpriteSheet {
       rows,
       (y) => List.generate(
         columns,
-        (x) => _mapImage(image, textureWidth, textureHeight, x, y),
+        (x) => _mapImagePath(image, textureWidth, textureHeight, x, y),
       ),
     );
   }
 
-  Sprite _mapImage(
+  Sprite _mapImagePath(
     Image image,
     int textureWidth,
     int textureHeight,
     int x,
     int y,
   ) {
-    return Sprite.fromImage(
+    return Sprite(
       image,
       x: (x * textureWidth).toDouble(),
       y: (y * textureHeight).toDouble(),