formatting, linting and refactorings

lib/animation.dart

@@ -13,18 +13,23 @@ class Animation {
 
   Animation.spriteList(this.sprites, {this.stepTime, this.lifeTime});
 
-  Animation.sequenced(String imagePath, int amount,
-      {double textureX = 0.0,
+  Animation.sequenced(
+    String imagePath,
+    int amount, {
+    double textureX = 0.0,
     double textureY = 0.0,
     double textureWidth = null,
-      double textureHeight = null}) {
-    sprites = new List<Sprite>(amount);
+    double textureHeight = null,
+  }) {
+    this.sprites = new List<Sprite>(amount);
     for (var i = 0; i < amount; i++) {
-      sprites[i] = new Sprite(imagePath,
+      this.sprites[i] = new Sprite(
+        imagePath,
         x: textureX + i * textureWidth,
         y: textureY,
         width: textureWidth,
-          height: textureHeight);
+        height: textureHeight,
+      );
     }
   }
 

lib/audio.dart

@@ -8,7 +8,7 @@ import 'package:audioplayers/audioplayer.dart';
 import 'package:path_provider/path_provider.dart';
 
 class Audio {
-  Map<String, File> loadedFiles = new Map();
+  Map<String, File> loadedFiles = {};
 
   void clear(String fileName) {
     loadedFiles.remove(fileName);

lib/box2d/box2d_component.dart

@@ -17,20 +17,20 @@ abstract class Box2DComponent extends Component {
   int positionIterations;
 
   World world;
-  List<Component> components = new List();
-
+  List<Component> components = [];
   Viewport viewport;
 
-  Box2DComponent(
-      {this.dimensions: const Size(0.0, 0.0),
+  Box2DComponent({
+    this.dimensions: const Size(0.0, 0.0),
     int worldPoolSize: DEFAULT_WORLD_POOL_SIZE,
     int worldPoolContainerSize: DEFAULT_WORLD_POOL_CONTAINER_SIZE,
     double gravity: DEFAULT_GRAVITY,
     this.velocityIterations: DEFAULT_VELOCITY_ITERATIONS,
     this.positionIterations: DEFAULT_POSITION_ITERATIONS,
-      double scale: DEFAULT_SCALE}) {
-    this.world = new World.withPool(new Vector2(0.0, gravity),
-        new DefaultWorldPool(worldPoolSize, worldPoolContainerSize));
+    double scale: DEFAULT_SCALE,
+  }) {
+    final pool = new DefaultWorldPool(worldPoolSize, worldPoolContainerSize);
+    this.world = new World.withPool(new Vector2(0.0, gravity), pool);
     this.viewport = new Viewport(dimensions, scale);
   }
 
@@ -66,10 +66,16 @@ abstract class Box2DComponent extends Component {
 
   void initializeWorld();
 
-  void cameraFollow(BodyComponent component,
-      {double horizontal, double vertical}) {
-    viewport.cameraFollow(component,
-        horizontal: horizontal, vertical: vertical);
+  void cameraFollow(
+    BodyComponent component, {
+    double horizontal,
+    double vertical,
+  }) {
+    viewport.cameraFollow(
+      component,
+      horizontal: horizontal,
+      vertical: vertical,
+    );
   }
 }
 
@@ -80,7 +86,7 @@ abstract class BodyComponent extends Component {
 
   Body body;
 
-  BodyComponent(this.box) {}
+  BodyComponent(this.box);
 
   World get world => box.world;
 
@@ -127,7 +133,7 @@ abstract class BodyComponent extends Component {
 
   void renderCircle(Canvas canvas, Offset center, double radius) {
     final Paint paint = new Paint()
-      ..color = new Color.fromARGB(255, 255, 255, 255);
+      ..color = const Color.fromARGB(255, 255, 255, 255);
     canvas.drawCircle(center, radius, paint);
   }
 
@@ -152,7 +158,7 @@ abstract class BodyComponent extends Component {
   void renderPolygon(Canvas canvas, List<Offset> points) {
     final path = new Path()..addPolygon(points, true);
     final Paint paint = new Paint()
-      ..color = new Color.fromARGB(255, 255, 255, 255);
+      ..color = const Color.fromARGB(255, 255, 255, 255);
     canvas.drawPath(path, paint);
   }
 }

lib/box2d/viewport.dart

@@ -14,9 +14,7 @@ class Viewport extends ViewportTransform {
 
   double worldAlignBottom(double height) => -(size.height / 2 / scale) + height;
 
-  /**
-   * Resizes the current view port.
-   */
+  /// Resizes the current view port.
   void resize(Size size) {
     this.size = size;
     this.extents =
@@ -25,24 +23,17 @@ class Viewport extends ViewportTransform {
         new Vector2.copy(new Vector2(size.width / 2, size.height / 2));
   }
 
-  /**
-   * Computes the number of horizontal world meters of this viewport considering a
-   * percentage of its width.
-   *
-   * @param percent percetage of the width in [0, 1] range
-   */
+  /// Computes the number of horizontal world meters of this viewport considering a percentage of its width.
+  ///
+  /// @param percent percetage of the width in [0, 1] range.
   double worldWidth(double percent) {
     return percent * (size.width / scale);
   }
 
-  /**
-   * Computes the scroll percentage of total screen width of the current viwerport
-   * center position.
-   *
-   * @param screens multiplies the visible screen with to create a bigger virtual
-   * screen.
-   * @return the percentage in the range of [0, 1]
-   */
+  /// Computes the scroll percentage of total screen width of the current viwerport center position.
+  ///
+  /// @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;
     var x = center.x + ((screens - 1) * size.width / 2);
@@ -51,14 +42,11 @@ class Viewport extends ViewportTransform {
     return x > 0 ? scroll : 1 - scroll;
   }
 
-  /**
-   * Follows the spececified body component using a sliding focus window
-   * defined as a percentage of the total viewport.
-   *
-   * @param component to follow.
-   * @param horizontal percentage of the horizontal viewport. Null means no horizontal following.
-   * @param vertical percentage of the vertical viewport. Null means no vertical following.
-   */
+  /// Follows the spececified body component using a sliding focus window defined as a percentage of the total viewport.
+  ///
+  /// @param component to follow.
+  /// @param horizontal percentage of the horizontal viewport. Null means no horizontal following.
+  /// @param vertical percentage of the vertical viewport. Null means no vertical following.
   void cameraFollow(BodyComponent component,
       {double horizontal, double vertical}) {
     Vector2 position = component.center;

lib/components/animation_component.dart

@@ -11,18 +11,26 @@ class AnimationComponent extends PositionComponent {
     this.height = height;
   }
 
-  AnimationComponent.sequenced(width, height, String imagePath, int amount,
-      {double textureX = 0.0,
+  AnimationComponent.sequenced(
+    width,
+    height,
+    String imagePath,
+    int amount, {
+    double textureX = 0.0,
     double textureY = 0.0,
     double textureWidth = null,
-      double textureHeight = null}) {
+    double textureHeight = null,
+  }) {
     this.width = width;
     this.height = height;
-    this.animation = new Animation.sequenced(imagePath, amount,
+    this.animation = new Animation.sequenced(
+      imagePath,
+      amount,
       textureX: textureX,
       textureY: textureY,
       textureWidth: textureWidth,
-        textureHeight: textureHeight);
+      textureHeight: textureHeight,
+    );
   }
 
   @override
@@ -32,7 +40,7 @@ class AnimationComponent extends PositionComponent {
 
   @override
   void render(Canvas canvas) {
-    if (loaded() && x != null && y != null) {
+    if (loaded()) {
       prepareCanvas(canvas);
       animation.getSprite().render(canvas, width, height);
     }

lib/components/component.dart

@@ -5,26 +5,48 @@ import '../sprite.dart';
 import '../position.dart';
 import 'package:flutter/painting.dart';
 
+/// This represents a Component for your game.
+///
+/// Components can be bullets flying on the screen, a spaship or your player's fighter.
+/// Anything that either renders or updates can be added to the list on [BaseGame]. It will deal with calling those methods for you.
+/// Components also have other methods that can help you out if you want to overwrite them.
 abstract class Component {
+  /// This method is called periodically by the game engine to request that your component updates itself.
+  ///
+  /// The time [t] in seconds (with microseconds precision provided by Flutter) since the last update cycle.
+  /// This time can vary according to hardware capacity, so make sure to update your state considering this.
+  /// All components on [BaseGame] are always updated by the same amount. The time each one takes to update adds up to the next update cycle.
   void update(double t);
 
+  /// Renders this component on the provided Canvas [c].
   void render(Canvas c);
 
+  /// This is a hook called by [BaseGame] to let this component know that the screen (or flame draw area) has been update.
+  ///
+  /// It receives the new size.
+  /// You can use the [Resizable] mixin if you want an implementation of this hook that keeps track of the current size.
   void resize(Size size) {}
 
-  bool loaded() {
-    return true;
-  }
-
-  bool destroy() {
-    return false;
-  }
-
-  bool isHud() {
-    return false;
-  }
+  /// Wether this component has been loaded yet. If not loaded, [BaseGame] will not try to render it.
+  ///
+  /// Sprite based components can use this to let [BaseGame] know not to try to render when the [Sprite] has not been loaded yet.
+  /// Note that for a more consistent experience, you can pre-load all your assets beforehand with [Flame.images.loadAll].
+  bool loaded() => true;
+
+  /// Wether this should be destroyed or not.
+  ///
+  /// It will be called once per component per loop, and if it returns true, [BaseGame] will mark your component for deletion and remove it before the next loop.
+  bool destroy() => false;
+
+  /// Wether this component is HUD object or not.
+  ///
+  /// HUD objects ignore the [BaseGame.camera] when rendered (so their position coordinates are considered relative to the device screen).
+  bool isHud() => false;
 }
 
+/// A [Component] implementation that represents a component that has a specific, possibly mutatable position on the screen.
+///
+/// It represents a rectangle of dimension ([width], [height]), on the position ([x], [y]), rotate around its center with angle [angle].
 abstract class PositionComponent extends Component {
   double x = 0.0, y = 0.0, angle = 0.0;
   double width = 0.0, height = 0.0;

lib/components/parallax_component.dart

@@ -8,7 +8,7 @@ import 'component.dart';
 
 class ParallaxRenderer {
   String filename;
-  Future future;
+  Future<Image> future;
 
   Image image;
   double scroll = 0.0;
@@ -17,7 +17,7 @@ class ParallaxRenderer {
     this.future = _load();
   }
 
-  Future _load() {
+  Future<Image> _load() {
     return Flame.images.load(filename).then((image) {
       this.image = image;
     });
@@ -42,7 +42,8 @@ class ParallaxRenderer {
       canvas: canvas,
       image: image,
       rect: fullRect,
-        repeat: ImageRepeat.repeatX);
+      repeat: ImageRepeat.repeatX,
+    );
   }
 }
 
@@ -59,23 +60,18 @@ abstract class ParallaxComponent extends PositionComponent {
     this._size = size;
   }
 
-  /**
-   * Loads the images defined by this list of filenames. All images
-   * are positioned at its scroll center.
-   *
-   * @param filenames Image filenames
-   */
+  /// Loads the images defined by this list of filenames. All images are positioned at its scroll center.
+  ///
+  /// @param filenames Image filenames
   void load(List<String> filenames) {
-    var futures =
-        filenames.fold(new List<Future>(), (List<Future> result, filename) {
-      var layer = new ParallaxRenderer(filename);
+    final futures = filenames.fold(<Future<Image>>[],
+        (List<Future<Image>> result, String filename) {
+      final layer = new ParallaxRenderer(filename);
       _layers.add(layer);
       result.add(layer.future);
       return result;
     });
-    Future.wait(futures).then((r) {
-      _loaded = true;
-    });
+    Future.wait(futures).then((r) => _loaded = true);
   }
 
   void updateScroll(int layerIndex, scroll) {
@@ -101,10 +97,8 @@ abstract class ParallaxComponent extends PositionComponent {
 
   void _drawLayers(Canvas canvas) {
     Rect rect = new Rect.fromPoints(
-        new Offset(0.0, 0.0), new Offset(_size.width, _size.height));
-    _layers.forEach((layer) {
-      layer.render(canvas, rect);
-    });
+        const Offset(0.0, 0.0), new Offset(_size.width, _size.height));
+    _layers.forEach((layer) => layer.render(canvas, rect));
   }
 
   @override
@@ -112,8 +106,8 @@ abstract class ParallaxComponent extends PositionComponent {
     if (!this.loaded()) {
       return;
     }
-    for (var i = 0; i < _layers.length; i++) {
-      var scroll = _layers[i].scroll;
+    for (int i = 0; i < _layers.length; i++) {
+      double scroll = _layers[i].scroll;
       scroll += (BASE_SPEED + i * LAYER_DELTA) * delta / _size.width;
       if (scroll > 1) {
         scroll = scroll % 1;

lib/game.dart

@@ -234,6 +234,7 @@ abstract class BaseGame extends Game {
   /// Returns `false` by default. Override to use the debug mode.
   /// In debug mode, the [_recordDt] method actually records every `dt` for statistics.
   /// Then, you can use the [fps] method to check the game FPS.
+  /// You can also use this value to enable other debug behaviors for your game.
   bool debugMode() => false;
 
   /// This is a hook that comes from the RenderBox to allow recording of render times and statistics.

lib/images.dart

@@ -4,7 +4,7 @@ import 'dart:ui';
 import 'dart:async';
 
 class Images {
-  Map<String, Image> loadedFiles = new Map();
+  Map<String, Image> loadedFiles = {};
 
   void clear(String fileName) {
     loadedFiles.remove(fileName);
@@ -29,9 +29,7 @@ class Images {
     ByteData data = await rootBundle.load('assets/images/' + name);
     Uint8List bytes = new Uint8List.view(data.buffer);
     Completer<Image> completer = new Completer();
-    decodeImageFromList(bytes, (image) {
-      completer.complete(image);
-    });
+    decodeImageFromList(bytes, (image) => completer.complete(image));
     return completer.future;
   }
 }

lib/sprite.dart

@@ -11,11 +11,13 @@ class Sprite {
 
   static final Paint paint = new Paint()..color = Colors.white;
 
-  Sprite(String fileName,
-      {double x = 0.0,
+  Sprite(
+    String fileName, {
+    double x = 0.0,
     double y = 0.0,
     double width = null,
-      double height = null}) {
+    double height = null,
+  }) {
     Flame.images.load(fileName).then((img) {
       if (width == null) {
         width = img.width.toDouble();
@@ -28,11 +30,13 @@ class Sprite {
     });
   }
 
-  Sprite.fromImage(this.image,
-      {double x = 0.0,
+  Sprite.fromImage(
+    this.image, {
+    double x = 0.0,
     double y = 0.0,
     double width = null,
-      double height = null}) {
+    double height = null,
+  }) {
     if (width == null) {
       width = image.width.toDouble();
     }
@@ -42,14 +46,21 @@ class Sprite {
     this.src = new Rect.fromLTWH(x, y, width, height);
   }
 
-  static Future<Sprite> loadSprite(String fileName,
-      {double x = 0.0,
+  static Future<Sprite> loadSprite(
+    String fileName, {
+    double x = 0.0,
     double y = 0.0,
     double width = null,
-      double height = null}) async {
+    double height = null,
+  }) async {
     Image image = await Flame.images.load(fileName);
-    return new Sprite.fromImage(image,
-        x: x, y: y, width: width, height: height);
+    return new Sprite.fromImage(
+      image,
+      x: x,
+      y: y,
+      width: width,
+      height: height,
+    );
   }
 
   bool loaded() {

lib/util.dart

@@ -17,7 +17,7 @@ class Util {
     // "In release mode we start off at 0x0 but we don't in debug mode"
     return await new Future<Size>(() {
       if (window.physicalSize.isEmpty) {
-        var completer = new Completer<Size>();
+        final completer = new Completer<Size>();
         window.onMetricsChanged = () {
           if (!window.physicalSize.isEmpty) {
             completer.complete(window.physicalSize / window.devicePixelRatio);
@@ -29,17 +29,28 @@ class Util {
     });
   }
 
-  material.TextPainter text(String text,
-      {double fontSize: 24.0,
+  material.TextPainter text(
+    String text, {
+    double fontSize: 24.0,
     Color color: material.Colors.black,
     String fontFamily: 'Arial',
     TextAlign textAlign: TextAlign.left,
-      TextDirection textDirection: TextDirection.ltr}) {
+    TextDirection textDirection: TextDirection.ltr,
+  }) {
     material.TextStyle style = new material.TextStyle(
-        color: color, fontSize: fontSize, fontFamily: fontFamily);
-    material.TextSpan span = new material.TextSpan(style: style, text: text);
+      color: color,
+      fontSize: fontSize,
+      fontFamily: fontFamily,
+    );
+    material.TextSpan span = new material.TextSpan(
+      style: style,
+      text: text,
+    );
     material.TextPainter tp = new material.TextPainter(
-        text: span, textAlign: textAlign, textDirection: textDirection);
+      text: span,
+      textAlign: textAlign,
+      textDirection: textDirection,
+    );
     tp.layout();
     return tp;
   }

test/box2d/viewport_test.dart

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