zero analyzer issues

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;