zero analyzer issues

doc/examples/animation_widget/lib/main.dart

@@ -41,7 +41,7 @@ class _MyHomePageState extends State<MyHomePage> {
 
   void _clickFab(GlobalKey<ScaffoldState> key) {
     key.currentState.showSnackBar(SnackBar(
-      content: Text('You clicked the FAB!'),
+      content: const Text('You clicked the FAB!'),
     ));
   }
 
@@ -51,28 +51,28 @@ class _MyHomePageState extends State<MyHomePage> {
     return Scaffold(
       key: key,
       appBar: AppBar(
-        title: Text('Animation as a Widget Demo'),
+        title: const Text('Animation as a Widget Demo'),
       ),
       body: Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            Text('Hi there! This is a regular Flutter app,'),
-            Text('with a complex widget tree and also'),
-            Text('some pretty sprite sheet animations :)'),
+            const Text('Hi there! This is a regular Flutter app,'),
+            const Text('with a complex widget tree and also'),
+            const Text('some pretty sprite sheet animations :)'),
             Flame.util.animationAsWidget(
                 _position,
                 animation.Animation.sequenced('minotaur.png', 19,
                     textureWidth: 96.0)),
-            Text('Neat, hum?'),
-            Text('Sprites from Elthen\'s amazing work on itch.io:'),
-            Text('https://elthen.itch.io/2d-pixel-art-minotaur-sprites'),
+            const Text('Neat, hum?'),
+            const Text('Sprites from Elthen\'s amazing work on itch.io:'),
+            const Text('https://elthen.itch.io/2d-pixel-art-minotaur-sprites'),
           ],
         ),
       ),
       floatingActionButton: FloatingActionButton(
         onPressed: () => _clickFab(key),
-        child: Icon(Icons.add),
+        child: const Icon(Icons.add),
       ),
     );
   }

doc/examples/animations/lib/main.dart

@@ -1,6 +1,6 @@
 import 'package:flame/flame.dart';
 import 'package:flame/game.dart';
-import 'package:flame/animation.dart' as FlameAnimation;
+import 'package:flame/animation.dart' as flame_animation;
 import 'package:flame/components/animation_component.dart';
 import 'package:flutter/material.dart';
 
@@ -11,10 +11,10 @@ class MyGame extends BaseGame {
     _start();
   }
 
-  _start() async {
-    Size size = await Flame.util.initialDimensions();
+  void _start() async {
+    final Size size = await Flame.util.initialDimensions();
 
-    final animation = await FlameAnimation.Animation.sequenced('chopper.png', 4,
+    final animation = flame_animation.Animation.sequenced('chopper.png', 4,
         textureWidth: 48, textureHeight: 48, stepTime: 0.15);
 
     final animationComponent = AnimationComponent(100, 100, animation);

doc/examples/aseprite/lib/main.dart

@@ -1,6 +1,6 @@
 import 'package:flame/flame.dart';
 import 'package:flame/game.dart';
-import 'package:flame/animation.dart' as FlameAnimation;
+import 'package:flame/animation.dart' as flame_animation;
 import 'package:flame/components/animation_component.dart';
 import 'package:flutter/material.dart';
 
@@ -11,10 +11,10 @@ class MyGame extends BaseGame {
     _start();
   }
 
-  _start() async {
+ void _start() async {
     final Size size = await Flame.util.initialDimensions();
 
-    final animation = await FlameAnimation.Animation.fromAsepriteData(
+    final animation = await flame_animation.Animation.fromAsepriteData(
         'chopper.png', 'chopper.json');
     final animationComponent = AnimationComponent(200, 200, animation);
 

doc/examples/svg/lib/main.dart

@@ -5,7 +5,7 @@ import 'package:flame/components/component.dart' show SvgComponent;
 
 import 'package:flutter/material.dart';
 
-void main() => runApp(MyGame());
+void main() => runApp(MyGame().widget);
 
 class MyGame extends BaseGame {
   Svg svgInstance;
@@ -15,7 +15,7 @@ class MyGame extends BaseGame {
     _start();
   }
 
-  _start() async {
+  void _start() {
     svgInstance = Svg('android.svg');
     android = SvgComponent.fromSvg(100, 100, svgInstance);
     android.x = 100;

doc/examples/text/lib/main.dart

@@ -16,7 +16,7 @@ TextConfig tiny = regular.withFontSize(12.0);
 
 class MyTextBox extends TextBoxComponent {
   MyTextBox(String text)
-      : super(text, config: tiny, boxConfig: TextBoxConfig(timePerChar: 0.05));
+      : super(text, config: tiny, boxConfig: const TextBoxConfig(timePerChar: 0.05));
 
   @override
   void drawBackground(Canvas c) {
@@ -35,7 +35,7 @@ class MyGame extends BaseGame {
     _start();
   }
 
-  _start() async {
+  void _start() async {
     final Size size = await Flame.util.initialDimensions();
 
     add(TextComponent('Hello, Flame', config: regular)

lib/animation.dart

@@ -34,6 +34,9 @@ class Animation {
   /// Whether the animation loops after the last sprite of the list, going back to the first, or keeps returning the last when done.
   bool loop = true;
 
+  /// Creates an animation given a list of frames.
+  Animation(this.frames, {this.loop = true});
+
   /// Creates an empty animation
   Animation.empty();
 
@@ -46,8 +49,7 @@ class Animation {
     frames = sprites.map((s) => Frame(s, stepTime)).toList();
   }
 
-  /// Creates an animation given a list of frames.
-  Animation(this.frames, {this.loop = true});
+
 
   /// Automatically creates a sequenced animation, that is, an animation based on a sprite sheet.
   ///
@@ -156,7 +158,7 @@ class Animation {
   }
 
   /// Sets a fixed step time to all frames.
-  void set stepTime(double stepTime) {
+  set stepTime(double stepTime) {
     frames.forEach((frame) => frame.stepTime = stepTime);
   }
 

lib/box2d/viewport.dart

@@ -6,6 +6,7 @@ import 'package:flame/box2d/box2d_component.dart';
 class Viewport extends ViewportTransform {
   Size size;
 
+  @override
   double scale;
 
   Viewport(this.size, this.scale)
@@ -36,7 +37,7 @@ 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}) {
+  double getCenterHorizontalScreenPercentage({double screens = 1.0}) {
     final width = size.width * screens;
     final x = center.x + ((screens - 1) * size.width / 2);
     final double rest = x.abs() % width;

lib/components/animation_component.dart

@@ -20,8 +20,8 @@ class AnimationComponent extends PositionComponent {
     int amount, {
     double textureX = 0.0,
     double textureY = 0.0,
-    double textureWidth = null,
-    double textureHeight = null,
+    double textureWidth,
+    double textureHeight,
   }) {
     this.width = width;
     this.height = height;

lib/components/component.dart

@@ -122,7 +122,7 @@ class SpriteComponent extends PositionComponent {
   }
 
   @override
-  render(Canvas canvas) {
+  void render(Canvas canvas) {
     prepareCanvas(canvas);
     sprite.render(canvas, width, height);
   }

lib/components/composed_component.dart

@@ -37,7 +37,7 @@ mixin ComposedComponent on Component {
       OrderedSet(Comparing.on((c) => c.priority()));
 
   @override
-  render(Canvas canvas) {
+  void render(Canvas canvas) {
     canvas.save();
     components.forEach((comp) => _renderComponent(canvas, comp));
     canvas.restore();

lib/components/parallax_component.dart

@@ -1,7 +1,7 @@
 import 'dart:async';
 import 'dart:ui';
 
-import 'package:flutter/src/painting/decoration_image.dart';
+import 'package:flutter/painting.dart';
 
 import '../flame.dart';
 import 'component.dart';
@@ -48,8 +48,8 @@ class ParallaxRenderer {
 }
 
 abstract class ParallaxComponent extends PositionComponent {
-  final BASE_SPEED = 30;
-  final LAYER_DELTA = 40;
+  final baseSpeed = 30;
+  final layerDelta = 40;
 
   final List<ParallaxRenderer> _layers = [];
   Size _size;
@@ -108,7 +108,7 @@ abstract class ParallaxComponent extends PositionComponent {
     }
     for (int i = 0; i < _layers.length; i++) {
       double scroll = _layers[i].scroll;
-      scroll += (BASE_SPEED + i * LAYER_DELTA) * delta / _size.width;
+      scroll += (baseSpeed + i * layerDelta) * delta / _size.width;
       if (scroll > 1) {
         scroll = scroll % 1;
       }

lib/components/resizable.dart

@@ -9,7 +9,7 @@ class Resizable {
   Size size;
 
   /// Implementation provided by this mixin to the resize hook.
-  resize(Size size) {
+  void resize(Size size) {
     this.size = size;
     children().where((e) => e != null).forEach((e) => e.resize(size));
   }

lib/components/text_box_component.dart

@@ -126,6 +126,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
 
   double get currentHeight => _withMargins((currentLine + 1) * _lineHeight);
 
+  @override
   void render(Canvas c) {
     if (_cache == null) {
       return;
@@ -168,6 +169,7 @@ class TextBoxComponent extends PositionComponent with Resizable {
     _cache = await _redrawCache();
   }
 
+  @override
   void update(double dt) {
     final int prevCurrentChar = currentChar;
     _lifeTime += dt;

lib/components/text_component.dart

@@ -1,6 +1,6 @@
 import 'dart:ui';
 
-import 'package:flutter/src/painting/text_painter.dart';
+import 'package:flutter/painting.dart';
 
 import 'component.dart';
 import '../position.dart';
@@ -10,14 +10,14 @@ class TextComponent extends PositionComponent {
   String _text;
   TextConfig _config;
 
-  get text => _text;
+  String get text => _text;
 
   set text(String text) {
     _text = text;
     _updateBox();
   }
 
-  get config => _config;
+  TextConfig get config => _config;
 
   set config(TextConfig config) {
     _config = config;

lib/components/tiled_component.dart

@@ -10,7 +10,7 @@ class TiledComponent extends Component {
   String filename;
   TileMap map;
   Image image;
-  Map<String, Image> images = Map<String, Image>();
+  Map<String, Image> images = <String, Image>{};
   Future future;
   bool _loaded = false;
 

lib/flame.dart

@@ -62,7 +62,8 @@ class FlameBiding extends BindingBase with GestureBinding, ServicesBinding {
   static FlameBiding instance;
 
   static FlameBiding ensureInitialized() {
-    if (FlameBiding.instance == null) FlameBiding();
+    if (FlameBiding.instance == null)
+      FlameBiding();
     return FlameBiding.instance;
   }
 }

lib/game.dart

@@ -112,7 +112,9 @@ class _GameRenderBox extends RenderBox with WidgetsBindingObserver {
   }
 
   void _tick(Duration timestamp) {
-    if (!attached) return;
+    if (!attached) {
+      return;
+    }
     _scheduleTick();
     _update(timestamp);
     markNeedsPaint();
@@ -166,7 +168,7 @@ abstract class BaseGame extends Game {
       OrderedSet(Comparing.on((c) => c.priority()));
 
   /// Components added by the [addLater] method
-  List<Component> _addLater = [];
+  final List<Component> _addLater = [];
 
   /// Current screen size, updated every resize via the [resize] method hook
   Size size;
@@ -175,7 +177,7 @@ abstract class BaseGame extends Game {
   Position camera = Position.empty();
 
   /// List of deltas used in debug mode to calculate FPS
-  List<double> _dts = [];
+  final List<double> _dts = [];
 
   /// This method is called for every component added, both via [add] and [addLater] methods.
   ///

lib/svg.dart

@@ -5,7 +5,7 @@ import 'flame.dart';
 import 'position.dart';
 
 class Svg {
-  DrawableRoot svgRoot = null;
+  DrawableRoot svgRoot;
   Size size;
 
   Svg(String fileName) {