use final

doc/examples/aseprite/lib/main.dart

@@ -12,7 +12,7 @@ class MyGame extends BaseGame {
   }
 
   _start() async {
-    Size size = await Flame.util.initialDimensions();
+    final Size size = await Flame.util.initialDimensions();
 
     final animation = await FlameAnimation.Animation.fromAsepriteData(
         'chopper.png', 'chopper.json');

doc/examples/text/lib/main.dart

@@ -20,8 +20,8 @@ class MyTextBox extends TextBoxComponent {
 
   @override
   void drawBackground(Canvas c) {
-    Rect rect = Rect.fromLTWH(0, 0, width, height);
+    final Rect rect = Rect.fromLTWH(0, 0, width, height);
-    c.drawRect(rect, Paint()..color = Color(0xFFFF00FF));
+    c.drawRect(rect, Paint()..color = const Color(0xFFFF00FF));
     c.drawRect(
         rect.deflate(boxConfig.margin),
         Paint()
@@ -36,7 +36,7 @@ class MyGame extends BaseGame {
   }
 
   _start() async {
-    Size size = await Flame.util.initialDimensions();
+    final Size size = await Flame.util.initialDimensions();
 
     add(TextComponent('Hello, Flame', config: regular)
       ..anchor = Anchor.topCenter

doc/examples/tiled/lib/main.dart

@@ -3,7 +3,7 @@ import 'package:flame/game.dart';
 import 'package:flutter/widgets.dart';
 
 void main() {
-  TiledGame game = TiledGame();
+  final TiledGame game = TiledGame();
   runApp(game.widget);
 }
 

example/lib/main.dart

@@ -41,7 +41,7 @@ class Square extends PositionComponent {
   @override
   void update(double t) {
     angle += SPEED * t;
-    angle %= (2 * math.pi);
+    angle %= 2 * math.pi;
   }
 }
 

lib/animation.dart

@@ -71,7 +71,7 @@ class Animation {
   }) {
     frames = List<Frame>(amount);
     for (var i = 0; i < amount; i++) {
-      Sprite sprite = Sprite(
+      final Sprite sprite = Sprite(
         imagePath,
         x: textureX + i * textureWidth,
         y: textureY,
@@ -94,7 +94,7 @@ class Animation {
   }) {
     frames = List<Frame>(amount);
     for (var i = 0; i < amount; i++) {
-      Sprite sprite = Sprite(
+      final Sprite sprite = Sprite(
         imagePath,
         x: textureX + i * textureWidth,
         y: textureY,
@@ -112,12 +112,12 @@ class Animation {
   /// [dataPath]: Animation's exported data in json format
   static Future<Animation> fromAsepriteData(
       String imagePath, String dataPath) async {
-    String content = await Flame.assets.readFile(dataPath);
+    final String content = await Flame.assets.readFile(dataPath);
-    Map<String, dynamic> json = jsonDecode(content);
+    final Map<String, dynamic> json = jsonDecode(content);
 
-    Map<String, dynamic> jsonFrames = json['frames'];
+    final Map<String, dynamic> jsonFrames = json['frames'];
 
-    var frames = jsonFrames.values.map((value) {
+    final frames = jsonFrames.values.map((value) {
       final frameData = value['frame'];
       final int x = frameData['x'];
       final int y = frameData['y'];
@@ -126,7 +126,7 @@ class Animation {
 
       final stepTime = value['duration'] / 1000;
 
-      Sprite sprite = Sprite(
+      final Sprite sprite = Sprite(
         imagePath,
         x: x.toDouble(),
         y: y.toDouble(),
@@ -203,7 +203,7 @@ class Animation {
 
   /// Returns a new Animation based on this animation, but with its frames in reversed order
   Animation reversed() {
-    return Animation(this.frames.reversed.toList(), loop: this.loop);
+    return Animation(frames.reversed.toList(), loop: loop);
   }
 
   /// Wether all sprites composing this animation are loaded.

lib/audio_pool.dart

@@ -19,7 +19,7 @@ class AudioPool {
   bool repeating;
   int minPlayers, maxPlayers;
 
-  Lock _lock = Lock();
+  final Lock _lock = Lock();
 
   AudioPool(this.sound,
       {this.repeating = false,
@@ -40,13 +40,13 @@ class AudioPool {
       if (availablePlayers.isEmpty) {
         availablePlayers.add(await _createNewAudioPlayer());
       }
-      AudioPlayer player = availablePlayers.removeAt(0);
+      final AudioPlayer player = availablePlayers.removeAt(0);
       currentPlayers[player.playerId] = player;
       await player.setVolume(volume);
       await player.resume();
-      Stoppable stop = () {
+      final Stoppable stop = () {
         _lock.synchronized(() async {
-          AudioPlayer p = currentPlayers.remove(player.playerId);
+          final AudioPlayer p = currentPlayers.remove(player.playerId);
           p.completionHandler = null;
           await p.stop();
           if (availablePlayers.length >= maxPlayers) {
@@ -66,8 +66,8 @@ class AudioPool {
   }
 
   Future<AudioPlayer> _createNewAudioPlayer() async {
-    AudioPlayer player = AudioPlayer();
+    final AudioPlayer player = AudioPlayer();
-    String url = (await cache.load(sound)).path;
+    final String url = (await cache.load(sound)).path;
     await player.setUrl(url);
     await player.setReleaseMode(ReleaseMode.STOP);
     return player;

lib/box2d/box2d_component.dart

@@ -21,17 +21,15 @@ abstract class Box2DComponent extends Component {
   Viewport viewport;
 
   Box2DComponent({
-    this.dimensions: null,
+    this.dimensions,
-    int worldPoolSize: DEFAULT_WORLD_POOL_SIZE,
+    int worldPoolSize= DEFAULT_WORLD_POOL_SIZE,
-    int worldPoolContainerSize: DEFAULT_WORLD_POOL_CONTAINER_SIZE,
+    int worldPoolContainerSize= DEFAULT_WORLD_POOL_CONTAINER_SIZE,
-    double gravity: DEFAULT_GRAVITY,
+    double gravity= DEFAULT_GRAVITY,
-    this.velocityIterations: DEFAULT_VELOCITY_ITERATIONS,
+    this.velocityIterations= DEFAULT_VELOCITY_ITERATIONS,
-    this.positionIterations: DEFAULT_POSITION_ITERATIONS,
+    this.positionIterations= DEFAULT_POSITION_ITERATIONS,
-    double scale: DEFAULT_SCALE,
+    double scale= DEFAULT_SCALE,
   }) {
-    if (dimensions == null) {
+    dimensions ??= window.physicalSize;
-      dimensions = window.physicalSize;
-    }
     final pool = DefaultWorldPool(worldPoolSize, worldPoolContainerSize);
     world = World.withPool(Vector2(0.0, gravity), pool);
     viewport = Viewport(dimensions, scale);
@@ -137,8 +135,8 @@ abstract class BodyComponent extends Component {
   Vector2 get center => body.worldCenter;
 
   void _renderCircle(Canvas canvas, Fixture fixture) {
-    Vector2 center = Vector2.zero();
+    final Vector2 center = Vector2.zero();
-    CircleShape circle = fixture.getShape();
+    final CircleShape circle = fixture.getShape();
     body.getWorldPointToOut(circle.p, center);
     viewport.getWorldToScreen(center, center);
     renderCircle(
@@ -152,16 +150,16 @@ abstract class BodyComponent extends Component {
   }
 
   void _renderPolygon(Canvas canvas, Fixture fixture) {
-    PolygonShape polygon = fixture.getShape();
+    final PolygonShape polygon = fixture.getShape();
     assert(polygon.count <= MAX_POLYGON_VERTICES);
-    List<Vector2> vertices = Vec2Array().get(polygon.count);
+    final List<Vector2> vertices = Vec2Array().get(polygon.count);
 
     for (int i = 0; i < polygon.count; ++i) {
       body.getWorldPointToOut(polygon.vertices[i], vertices[i]);
       viewport.getWorldToScreen(vertices[i], vertices[i]);
     }
 
-    List<Offset> points = [];
+    final List<Offset> points = [];
     for (int i = 0; i < polygon.count; i++) {
       points.add(Offset(vertices[i].x, vertices[i].y));
     }

lib/box2d/viewport.dart

@@ -37,10 +37,10 @@ class Viewport extends ViewportTransform {
   /// @param screens multiplies the visible screen with to create a bigger virtual screen.
   /// @return the percentage in the range of [0, 1]
   double getCenterHorizontalScreenPercentage({double screens: 1.0}) {
-    var width = size.width * screens;
+    final width = size.width * screens;
-    var x = center.x + ((screens - 1) * size.width / 2);
+    final x = center.x + ((screens - 1) * size.width / 2);
-    double rest = x.abs() % width;
+    final double rest = x.abs() % width;
-    double scroll = rest / width;
+    final double scroll = rest / width;
     return x > 0 ? scroll : 1 - scroll;
   }
 
@@ -51,17 +51,17 @@ class Viewport extends ViewportTransform {
   /// @param vertical percentage of the vertical viewport. Null means no vertical following.
   void cameraFollow(BodyComponent component,
       {double horizontal, double vertical}) {
-    Vector2 position = component.center;
+    final Vector2 position = component.center;
 
     double x = center.x;
     double y = center.y;
 
     if (horizontal != null) {
-      Vector2 temp = Vector2.zero();
+      final Vector2 temp = Vector2.zero();
       getWorldToScreen(position, temp);
 
-      var margin = horizontal / 2 * size.width / 2;
+      final margin = horizontal / 2 * size.width / 2;
-      var focus = size.width / 2 - temp.x;
+      final focus = size.width / 2 - temp.x;
 
       if (focus.abs() > margin) {
         x = size.width / 2 +
@@ -71,11 +71,11 @@ class Viewport extends ViewportTransform {
     }
 
     if (vertical != null) {
-      Vector2 temp = Vector2.zero();
+      final Vector2 temp = Vector2.zero();
       getWorldToScreen(position, temp);
 
-      var margin = vertical / 2 * size.height / 2;
+      final margin = vertical / 2 * size.height / 2;
-      var focus = size.height / 2 - temp.y;
+      final focus = size.height / 2 - temp.y;
 
       if (focus.abs() > margin) {
         y = size.height / 2 +

lib/components/component.dart

@@ -96,8 +96,8 @@ abstract class PositionComponent extends Component {
     canvas.translate(x, y);
 
     canvas.rotate(angle);
-    double dx = -anchor.relativePosition.dx * width;
+    final double dx = -anchor.relativePosition.dx * width;
-    double dy = -anchor.relativePosition.dy * height;
+    final double dy = -anchor.relativePosition.dy * height;
     canvas.translate(dx, dy);
   }
 }
@@ -145,7 +145,7 @@ class SvgComponent extends PositionComponent {
   }
  
   @override
-  render(Canvas canvas) {
+  void render(Canvas canvas) {
     prepareCanvas(canvas);
     svg.render(canvas, width, height);
   }

lib/components/composed_component.dart

@@ -60,7 +60,7 @@ mixin ComposedComponent on Component {
 
     if (this is Resizable) {
       // first time resize
-      Resizable thisResizable = this as Resizable;
+      final Resizable thisResizable = this as Resizable;
       if (thisResizable.size != null) {
         c.resize(thisResizable.size);
       }

lib/components/debug_component.dart

@@ -17,18 +17,24 @@ class DebugComponent extends PositionComponent {
     ..style = PaintingStyle.stroke;
 
   /// Don't do anything (change as desired)
+  @override
   void update(double t) {}
 
   /// Renders the rectangle
+  @override
   void render(Canvas c) {
     prepareCanvas(c);
     c.drawRect(Rect.fromLTWH(0.0, 0.0, width, height), paint);
   }
 
   /// Don't do anything (change as desired)
+  @override
   void resize(Size size) {}
 
+  @override
   bool loaded() => true;
+  @override
   bool destroy() => false;
+  @override
   bool isHud() => false;
 }

lib/components/parallax_component.dart

@@ -14,7 +14,7 @@ class ParallaxRenderer {
   double scroll = 0.0;
 
   ParallaxRenderer(this.filename) {
-    this.future = _load();
+    future = _load();
   }
 
   Future<Image> _load() {
@@ -30,12 +30,12 @@ class ParallaxRenderer {
       return;
     }
 
-    var imageHeight = image.height / window.devicePixelRatio;
+    final imageHeight = image.height / window.devicePixelRatio;
-    var imageWidth =
+    final imageWidth =
         (rect.height / imageHeight) * (image.width / window.devicePixelRatio);
-    var count = rect.width / imageWidth;
+    final count = rect.width / imageWidth;
 
-    Rect fullRect = Rect.fromLTWH(
+    final Rect fullRect = Rect.fromLTWH(
         -scroll * imageWidth, rect.top, (count + 1) * imageWidth, rect.height);
 
     paintImage(
@@ -51,7 +51,7 @@ abstract class ParallaxComponent extends PositionComponent {
   final BASE_SPEED = 30;
   final LAYER_DELTA = 40;
 
-  List<ParallaxRenderer> _layers = [];
+  final List<ParallaxRenderer> _layers = [];
   Size _size;
   bool _loaded = false;
 
@@ -96,7 +96,7 @@ abstract class ParallaxComponent extends PositionComponent {
   }
 
   void _drawLayers(Canvas canvas) {
-    Rect rect = Rect.fromPoints(
+    final Rect rect = Rect.fromPoints(
         const Offset(0.0, 0.0), Offset(_size.width, _size.height));
     _layers.forEach((layer) => layer.render(canvas, rect));
   }

lib/components/text_box_component.dart

@@ -16,10 +16,10 @@ class TextBoxConfig {
   final double dismissDelay;
 
   const TextBoxConfig({
-    this.maxWidth: 200.0,
+    this.maxWidth= 200.0,
-    this.margin: 8.0,
+    this.margin= 8.0,
-    this.timePerChar: 0.0,
+    this.timePerChar= 0.0,
-    this.dismissDelay: 0.0,
+    this.dismissDelay= 0.0,
   });
 }
 
@@ -51,11 +51,9 @@ class TextBoxComponent extends PositionComponent with Resizable {
     _text = text;
     _lines = [''];
     text.split(' ').forEach((word) {
-      String possibleLine = _lines.last + ' ' + word;
+      final String possibleLine = _lines.last + ' ' + word;
-      widgets.TextPainter p = config.toTextPainter(possibleLine);
+      final widgets.TextPainter p = config.toTextPainter(possibleLine);
-      if (_lineHeight == null) {
+      _lineHeight ??= p.height;
-        _lineHeight = p.height;
-      }
       if (p.width <= _boxConfig.maxWidth - 2 * _boxConfig.margin) {
         _lines.last = possibleLine;
         _updateMaxWidth(p.width);
@@ -84,7 +82,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
 
   int get currentLine {
     int totalCharCount = 0;
-    int _currentChar = currentChar;
+    final int _currentChar = currentChar;
     for (int i = 0; i < _lines.length; i++) {
       totalCharCount += _lines[i].length;
       if (totalCharCount > _currentChar) {
@@ -115,10 +113,10 @@ class TextBoxComponent extends PositionComponent with Resizable {
   double get currentWidth {
     int i = 0;
     int totalCharCount = 0;
-    int _currentChar = currentChar;
+    final int _currentChar = currentChar;
-    int _currentLine = currentLine;
+    final int _currentLine = currentLine;
     return _lines.sublist(0, _currentLine + 1).map((line) {
-      int charCount =
+      final int charCount =
           (i < _currentLine) ? line.length : (_currentChar - totalCharCount);
       totalCharCount += line.length;
       i++;
@@ -137,8 +135,8 @@ class TextBoxComponent extends PositionComponent with Resizable {
   }
 
   Future<Image> _redrawCache() {
-    PictureRecorder recorder = PictureRecorder();
+    final PictureRecorder recorder = PictureRecorder();
-    Canvas c = Canvas(
+    final Canvas c = Canvas(
         recorder, Rect.fromLTWH(0.0, 0.0, width.toDouble(), height.toDouble()));
     _fullRender(c);
     return recorder.endRecording().toImage(width.toInt(), height.toInt());
@@ -149,7 +147,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
   void _fullRender(Canvas c) {
     drawBackground(c);
 
-    int _currentLine = currentLine;
+    final int _currentLine = currentLine;
     int charCount = 0;
     double dy = _boxConfig.margin;
     for (int line = 0; line < _currentLine; line++) {
@@ -159,7 +157,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
           .paint(c, Offset(_boxConfig.margin, dy));
       dy += _lineHeight;
     }
-    int max = math.min(currentChar - charCount, _lines[_currentLine].length);
+    final int max = math.min(currentChar - charCount, _lines[_currentLine].length);
     _config
         .toTextPainter(_lines[_currentLine].substring(0, max))
         .paint(c, Offset(_boxConfig.margin, dy));
@@ -170,7 +168,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
   }
 
   void update(double dt) {
-    int prevCurrentChar = currentChar;
+    final int prevCurrentChar = currentChar;
     _lifeTime += dt;
     if (prevCurrentChar != currentChar) {
       redrawLater();

lib/components/text_component.dart

@@ -30,7 +30,7 @@ class TextComponent extends PositionComponent {
   }
 
   void _updateBox() {
-    TextPainter tp = config.toTextPainter(text);
+    final TextPainter tp = config.toTextPainter(text);
     width = tp.width;
     height = tp.height;
   }

lib/components/tiled_component.dart

@@ -29,13 +29,13 @@ class TiledComponent extends Component {
 
   Future<TileMap> _loadMap() {
     return Flame.bundle.loadString('assets/tiles/' + filename).then((contents) {
-      var parser = TileMapParser();
+      final parser = TileMapParser();
       return parser.parse(contents);
     });
   }
 
   Future<Map<String, Image>> _loadImages(TileMap map) async {
-    Map<String, Image> result = {};
+    final Map<String, Image> result = {};
     await Future.forEach(map.tilesets, (tileset) async {
       await Future.forEach(tileset.images, (tmxImage) async {
         result[tmxImage.source] = await Flame.images.load(tmxImage.source);
@@ -44,6 +44,7 @@ class TiledComponent extends Component {
     return result;
   }
 
+  @override
   bool loaded() => _loaded;
 
   @override
@@ -65,12 +66,12 @@ class TiledComponent extends Component {
         return;
       }
 
-      var image = images[tile.image.source];
+      final image = images[tile.image.source];
 
-      var rect = tile.computeDrawRect();
+      final rect = tile.computeDrawRect();
-      var src = Rect.fromLTWH(rect.left.toDouble(), rect.top.toDouble(),
+      final src = Rect.fromLTWH(rect.left.toDouble(), rect.top.toDouble(),
           rect.width.toDouble(), rect.height.toDouble());
-      var dst = Rect.fromLTWH(tile.x.toDouble(), tile.y.toDouble(),
+      final dst = Rect.fromLTWH(tile.x.toDouble(), tile.y.toDouble(),
           rect.width.toDouble(), rect.height.toDouble());
 
       c.drawImageRect(image, src, dst, paint);

lib/game.dart

@@ -119,7 +119,7 @@ class _GameRenderBox extends RenderBox with WidgetsBindingObserver {
   }
 
   void _update(Duration now) {
-    double dt = _computeDeltaT(now);
+    final double dt = _computeDeltaT(now);
     game._recordDt(dt);
     game.update(dt);
   }
@@ -280,12 +280,12 @@ abstract class BaseGame extends Game {
   /// So it's technically updates per second, but the relation between updates and renders is 1:1.
   /// Returns 0 if empty.
   double fps([int average = 1]) {
-    List<double> dts = _dts.sublist(math.max(0, _dts.length - average));
+    final List<double> dts = _dts.sublist(math.max(0, _dts.length - average));
     if (dts.isEmpty) {
       return 0.0;
     }
-    double dtSum = dts.reduce((s, t) => s + t);
+    final double dtSum = dts.reduce((s, t) => s + t);
-    double averageDt = dtSum / average;
+    final double averageDt = dtSum / average;
     return 1 / averageDt;
   }
 
@@ -341,7 +341,7 @@ class _EmbeddedGameWidgetState extends State<EmbeddedGameWidget> {
   }
 
   void _afterLayout(_) {
-    RenderBox box = context.findRenderObject();
+    final RenderBox box = context.findRenderObject();
     widget.game.builder.offset = box.localToGlobal(Offset.zero);
   }
 

lib/images.dart

@@ -27,9 +27,9 @@ class Images {
   }
 
   Future<Image> _fetchToMemory(String name) async {
-    ByteData data = await Flame.bundle.load('assets/images/' + name);
+    final ByteData data = await Flame.bundle.load('assets/images/' + name);
-    Uint8List bytes = Uint8List.view(data.buffer);
+    final Uint8List bytes = Uint8List.view(data.buffer);
-    Completer<Image> completer = Completer();
+    final Completer<Image> completer = Completer();
     decodeImageFromList(bytes, (image) => completer.complete(image));
     return completer.future;
   }

lib/position.dart

@@ -68,8 +68,8 @@ class Position {
   }
 
   Position rotate(double angle) {
-    double nx = math.cos(angle) * x - math.sin(angle) * y;
+    final double nx = math.cos(angle) * x - math.sin(angle) * y;
-    double ny = math.sin(angle) * x + math.cos(angle) * y;
+    final double ny = math.sin(angle) * x + math.cos(angle) * y;
     x = nx;
     y = ny;
     return this;
@@ -109,10 +109,10 @@ class Position {
   }
 
   static ui.Rect bounds(List<Position> pts) {
-    double minx = pts.map((e) => e.x).reduce(math.min);
+    final double minx = pts.map((e) => e.x).reduce(math.min);
-    double maxx = pts.map((e) => e.x).reduce(math.max);
+    final double maxx = pts.map((e) => e.x).reduce(math.max);
-    double miny = pts.map((e) => e.y).reduce(math.min);
+    final double miny = pts.map((e) => e.y).reduce(math.min);
-    double maxy = pts.map((e) => e.y).reduce(math.max);
+    final double maxy = pts.map((e) => e.y).reduce(math.max);
     return ui.Rect.fromPoints(ui.Offset(minx, miny), ui.Offset(maxx, maxy));
   }
 }

lib/sprite.dart

@@ -14,16 +14,12 @@ class Sprite {
     String fileName, {
     double x = 0.0,
     double y = 0.0,
-    double width = null,
+    double width,
-    double height = null,
+    double height,
   }) {
     Flame.images.load(fileName).then((img) {
-      if (width == null) {
+      width ??= img.width.toDouble();
-        width = img.width.toDouble();
+      height ??= img.height.toDouble();
-      }
-      if (height == null) {
-        height = img.height.toDouble();
-      }
       image = img;
       src = Rect.fromLTWH(x, y, width, height);
     });
@@ -33,15 +29,11 @@ class Sprite {
     this.image, {
     double x = 0.0,
     double y = 0.0,
-    double width = null,
+    double width,
-    double height = null,
+    double height,
   }) {
-    if (width == null) {
+    width ??= image.width.toDouble();
-      width = image.width.toDouble();
+    height ??= image.height.toDouble();
-    }
-    if (height == null) {
-      height = image.height.toDouble();
-    }
     src = Rect.fromLTWH(x, y, width, height);
   }
 
@@ -49,10 +41,10 @@ class Sprite {
     String fileName, {
     double x = 0.0,
     double y = 0.0,
-    double width = null,
+    double width,
-    double height = null,
+    double height,
   }) async {
-    Image image = await Flame.images.load(fileName);
+    final Image image = await Flame.images.load(fileName);
     return Sprite.fromImage(
       image,
       x: x,

lib/svg.dart

@@ -10,7 +10,7 @@ class Svg {
 
   Svg(String fileName) {
     Flame.assets.readFile(fileName).then((svgString) async {
-      this.svgRoot = await svg.fromSvgString(svgString, svgString);
+      svgRoot = await svg.fromSvgString(svgString, svgString);
     });
   }
 
@@ -18,7 +18,7 @@ class Svg {
   ///
   /// If not loaded, does nothing
   void render(Canvas canvas, double width, double height) {
-    if (!this.loaded()) {
+    if (!loaded()) {
       return;
     }
 
@@ -30,7 +30,7 @@ class Svg {
   ///
   /// If not loaded, does nothing
   void renderPosition(Canvas canvas, Position position, double width, double height) {
-    if (!this.loaded()) {
+    if (!loaded()) {
       return;
     }
 

lib/text_config.dart

@@ -53,11 +53,11 @@ class TextConfig {
   ///
   /// Every parameter can be specified.
   const TextConfig({
-    this.fontSize: 24.0,
+    this.fontSize= 24.0,
-    this.color: const Color(0xFF000000),
+    this.color= const Color(0xFF000000),
-    this.fontFamily: 'Arial',
+    this.fontFamily= 'Arial',
-    this.textAlign: TextAlign.left,
+    this.textAlign= TextAlign.left,
-    this.textDirection: TextDirection.ltr,
+    this.textDirection= TextDirection.ltr,
   });
 
   /// Renders a given [text] in a given position [p] using the provided [canvas] and [anchor].
@@ -70,9 +70,9 @@ class TextConfig {
   ///     const TextConfig config = TextConfig(fontSize: 48.0, fontFamily: 'Awesome Font', anchor: Anchor.rightBottom);
   ///     config.render(c, Offset(size.width - 10, size.height - 10);
   void render(Canvas canvas, String text, Position p,
-      {Anchor anchor: Anchor.topLeft}) {
+      {Anchor anchor= Anchor.topLeft}) {
-    material.TextPainter tp = toTextPainter(text);
+    final material.TextPainter tp = toTextPainter(text);
-    Position translatedPosition =
+    final Position translatedPosition =
         anchor.translate(p, Position.fromSize(tp.size));
     tp.paint(canvas, translatedPosition.toOffset());
   }
@@ -90,16 +90,16 @@ class TextConfig {
   /// However, you probably want to use the [render] method witch already renders for you considering the anchor.
   /// That way, you don't need to perform the math for yourself.
   material.TextPainter toTextPainter(String text) {
-    material.TextStyle style = material.TextStyle(
+    final material.TextStyle style = material.TextStyle(
       color: color,
       fontSize: fontSize,
       fontFamily: fontFamily,
     );
-    material.TextSpan span = material.TextSpan(
+    final material.TextSpan span = material.TextSpan(
       style: style,
       text: text,
     );
-    material.TextPainter tp = material.TextPainter(
+    final material.TextPainter tp = material.TextPainter(
       text: span,
       textAlign: textAlign,
       textDirection: textDirection,

test/components/box2d/viewport_test.dart

@@ -4,7 +4,7 @@ import 'package:flame/box2d/viewport.dart';
 import 'package:test/test.dart';
 
 void main() {
-  final viewport = Viewport(Size(100.0, 100.0), 1.0);
+  final viewport = Viewport(const Size(100.0, 100.0), 1.0);
 
   group('getCenterHorizontalScreenPercentage', () {
     test('center starts in the middle', () {

test/components/component_test.dart

@@ -7,7 +7,7 @@ import 'package:flame/position.dart';
 void main() {
   group('component test', () {
     test('test get/set x/y or position', () {
-      PositionComponent c = SpriteComponent();
+      final PositionComponent c = SpriteComponent();
       c.x = 2.2;
       c.y = 3.4;
       expect(c.toPosition().x, 2.2);
@@ -19,7 +19,7 @@ void main() {
     });
 
     test('test get/set widt/height or size', () {
-      PositionComponent c = SpriteComponent();
+      final PositionComponent c = SpriteComponent();
       c.width = 2.2;
       c.height = 3.4;
       expect(c.toSize().x, 2.2);
@@ -31,7 +31,7 @@ void main() {
     });
 
     test('test get/set rect', () {
-      PositionComponent c = SpriteComponent();
+      final PositionComponent c = SpriteComponent();
       c.x = 0.0;
       c.y = 1.0;
       c.width = 2.0;

test/components/tiled_test.dart

@@ -10,7 +10,7 @@ import 'package:test/test.dart';
 void main() {
   test('my first widget test', () async {
     await Flame.init(bundle: TestAssetBundle());
-    var tiled = TiledComponent('x');
+    final tiled = TiledComponent('x');
     await tiled.future;
     expect(1, equals(1));
   });

test/position_test.dart

@@ -10,16 +10,16 @@ void expectDouble(double d1, double d2) {
 void main() {
   group('position test', () {
     test('test add', () {
-      Position p = Position(0.0, 5.0);
+      final Position p = Position(0.0, 5.0);
-      Position p2 = p.add(Position(5.0, 5.0));
+      final Position p2 = p.add(Position(5.0, 5.0));
       expect(p, p2);
       expectDouble(p.x, 5.0);
       expectDouble(p.y, 10.0);
     });
 
     test('test clone', () {
-      Position p = Position(1.0, 0.0);
+      final Position p = Position(1.0, 0.0);
-      Position clone = p.clone();
+      final Position clone = p.clone();
 
       clone.times(2.0);
       expectDouble(p.x, 1.0);
@@ -27,20 +27,20 @@ void main() {
     });
 
     test('test rotate', () {
-      Position p = Position(1.0, 0.0).rotate(math.pi / 2);
+      final Position p = Position(1.0, 0.0).rotate(math.pi / 2);
       expectDouble(p.x, 0.0);
       expectDouble(p.y, 1.0);
     });
 
     test('test length', () {
-      Position p = Position(3.0, 4.0);
+      final Position p = Position(3.0, 4.0);
       expectDouble(p.length(), 5.0);
     });
 
     test('test distance', () {
-      Position p1 = Position(10.0, 20.0);
+      final Position p1 = Position(10.0, 20.0);
-      Position p2 = Position(13.0, 24.0);
+      final Position p2 = Position(13.0, 24.0);
-      double result = p1.distance(p2);
+      final double result = p1.distance(p2);
       expectDouble(result, 5.0);
     });
   });

test/resizable_test.dart

@@ -23,23 +23,23 @@ Size size = const Size(1.0, 1.0);
 void main() {
   group('resizable test', () {
     test('propagate resize to children', () {
-      MyComponent a = MyComponent('a');
+      final MyComponent a = MyComponent('a');
-      MyComponent b = MyComponent('b', myChildren: [a]);
+      final MyComponent b = MyComponent('b', myChildren: [a]);
       b.resize(size);
       expect(a.size, size);
     });
 
     test('game calls resize on add', () {
-      MyComponent a = MyComponent('a');
+      final MyComponent a = MyComponent('a');
-      MyGame game = MyGame();
+      final MyGame game = MyGame();
       game.resize(size);
       game.add(a);
       expect(a.size, size);
     });
 
     test('game calls resize after added', () {
-      MyComponent a = MyComponent('a');
+      final MyComponent a = MyComponent('a');
-      MyGame game = MyGame();
+      final MyGame game = MyGame();
       game.add(a);
       game.resize(size);
       expect(a.size, size);