feat: v2.0.1 support null safety

support null safety also known as void safety

Author: drawcall

.gitignore

@@ -23,3 +23,4 @@ example/.history
 example/.svn/
 example/pubspec.lock
 example/.vscode/
+.vscode/

example/lib/main.dart

@@ -18,7 +18,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
+  MyHomePage({Key? key, required this.title}) : super(key: key);
 
   final String title;
 
@@ -34,17 +34,22 @@ class _MyHomePageState extends State<MyHomePage> {
           title: Text(widget.title),
         ),
         body: Center(
-          child: Zerker(app: MyZKApp(), clip: true, interactive: true, width: 350, height: 350),
+          child: Zerker(
+              app: MyZKApp(),
+              clip: true,
+              interactive: true,
+              width: 350,
+              height: 350),
         ));
   }
 }
 
 class MyZKApp extends ZKApp {
   bool _loaded = false;
   bool _jumping = false;
-  ZKSprite boy;
-  ZKText title;
-  ZKScrollBg bg;
+  ZKSprite? boy;
+  ZKText? title;
+  ZKScrollBg? bg;
 
   @override
   init() {
@@ -75,8 +80,11 @@ class MyZKApp extends ZKApp {
       ..position.x = appWidth / 2
       ..position.y = 20
       ..text = "Please click anywhere"
-      ..setStyle(color: Colors.blueGrey, backgroundColor: Colors.greenAccent, textAlign: TextAlign.center);
-    stage.addChild(title);
+      ..setStyle(
+          color: Colors.blueGrey,
+          backgroundColor: Colors.greenAccent,
+          textAlign: TextAlign.center);
+    stage.addChild(title!);
 
     // add boy
     boy = ZKSprite(key: "boy")
@@ -88,37 +96,40 @@ class MyZKApp extends ZKApp {
       ..animator.make("jump", ["Jump ({1-15}).png"])
       ..animator.make("dead", ["Dead ({1-15}).png"])
       ..animator.play("run", 25, true);
-    stage.addChild(boy);
+    stage.addChild(boy!);
 
     // add bg
     bg = ZKScrollBg(key: "bg", time: 4 * 1000)
       ..setScale(0.5)
       ..position.y = appHeight
       ..anchor.y = 1;
-    stage.addChildAt(bg, 0);
+    stage.addChildAt(bg!, 0);
 
     _addAction();
   }
 
   _addAction() {
-    boy.onTapDown = (event) {
-      bg.stop();
+    boy?.onTapDown = (event) {
+      bg?.stop();
       _jumping = false;
-      boy.animator.play("dead", 20);
+      boy?.animator.play("dead", 20);
     };
 
     stage.onTapDown = (event) {
       if (event.target == boy) return;
       if (_jumping) return;
 
-      bg.play();
+      bg?.play();
       _jumping = true;
-      boy.animator.play("jump", 20);
+      boy?.animator.play("jump", 20);
       ZKTween(boy)
           .to({"y": appHeight - 120}, 500)
           .easing(Ease.circ.easeOut)
-          .chain(ZKTween(boy).to({"y": appHeight - 16}, 500).easing(Ease.circ.easeIn).onComplete((obj) {
-                boy.animator.play("run", 25, true);
+          .chain(ZKTween(boy)
+              .to({"y": appHeight - 16}, 500)
+              .easing(Ease.circ.easeIn)
+              .onComplete((obj) {
+                boy?.animator.play("run", 25, true);
                 _jumping = false;
               }))
           .start();

example/pubspec.yaml

@@ -14,7 +14,7 @@ description: A new Flutter project.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
   flutter:
@@ -23,7 +23,8 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2
-  zerker: ^1.4.1
+  zerker:
+    path: ../
 
 dev_dependencies:
   flutter_test:

example/test/widget_test.dart

@@ -8,7 +8,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../main.dart';
+import '../lib/main.dart';
 
 void main() {
   testWidgets('Counter increments smoke test', (WidgetTester tester) async {

lib/src/animate/animation.dart

@@ -4,17 +4,17 @@ import '../utils/util.dart';
 List defaultList = Util.convertConsecutiveList(['0-42']);
 
 class Animation {
-  Function onComplete;
+  Function? onComplete;
 
-  String name;
-  String framesType;
+  String name = '';
+  String framesType = '';
   bool loop = false;
 
   int index = 0;
   int elapsed = 0;
   double delay = 0;
 
-  List _frames;
+  List _frames = [];
 
   ////////////////////////////////////////////////////////////
   ///
@@ -48,9 +48,9 @@ class Animation {
   int _rate = Constant.RATE;
 
   Animation(String name,
-      [List frames, int rate = Constant.RATE, bool loop = false]) {
+      [List? frames, int rate = Constant.RATE, bool loop = false]) {
     this.name = name;
-    this.rate = rate ?? Constant.RATE;
+    this.rate = rate;
     this.loop = loop;
 
     if (frames == null) {
@@ -63,12 +63,12 @@ class Animation {
   }
 
   dynamic getCurrentFrameKey() {
-    if (this.frames == null) return 0;
+    if (this.frames.length == 0) return 0;
     return this.frames[this.index];
   }
 
   void update(int seconds) {
-    if (this.frames == null) return;
+    if (this.frames.length == 0) return;
 
     this.elapsed += seconds;
     if (this.elapsed >= this.delay) {
@@ -84,7 +84,7 @@ class Animation {
       }
 
       if (this.loop != true && onComplete != null) {
-        onComplete();
+        onComplete!();
       }
     }
   }
@@ -95,14 +95,9 @@ class Animation {
   }
 
   void dispose() {
-    this.name = null;
     this.onComplete = null;
     this.elapsed = 0;
     this.index = 0;
-
-    if (this.frames != null) {
-      this.frames.clear();
-      this.frames = null;
-    }
+    this.frames.clear();
   }
 }

lib/src/animate/animator.dart

@@ -11,11 +11,11 @@ import '../core/constant.dart';
 ///
 ////////////////////////////////////////////////////////////
 class Animator {
-  Function onComplete;
+  Function? onComplete;
   String status = "stop";
 
   ListMap _aniList = new ListMap();
-  Animation _currentAni;
+  Animation? _currentAni;
   int _framesLength = -1;
 
   bool get isEnabled {
@@ -32,27 +32,28 @@ class Animator {
   }
 
   dynamic getCurrentFrameKey() {
-    return _currentAni != null ? _currentAni.getCurrentFrameKey() : 0;
+    return _currentAni != null ? _currentAni?.getCurrentFrameKey() : 0;
   }
 
   ////////////////////////////////////////////////////////////
   ///
   /// Play and Stop
   ///
   ////////////////////////////////////////////////////////////
-  void play(String name, [int rate, bool loop = false]) {
-    Animation ani = _aniList.getItem(name);
-    if (ani == null)
+  void play(String name, [int? rate, bool loop = false]) {
+    Animation? ani = _aniList.getItem(name);
+    if (ani == null) {
       throw ("Zerker:: Sorry, there is no corresponding animation information.");
-
-    ani.rate = rate ?? ani.rate;
-    ani.loop = loop ?? ani.loop;
-    _currentAni = ani;
-    _currentAni.reset();
-    this.status = "play";
+    } else {
+      ani.rate = rate ?? ani.rate;
+      ani.loop = loop;
+      _currentAni = ani;
+      _currentAni?.reset();
+      this.status = "play";
+    }
   }
 
-  void stop([String name]) {
+  void stop([String? name]) {
     if (name != null) {
       this.play(name, 9999);
     }
@@ -66,7 +67,7 @@ class Animator {
   ///
   ////////////////////////////////////////////////////////////
   void make(String name,
-      [List frames, int rate = Constant.RATE, bool loop = false]) {
+      [List? frames, int rate = Constant.RATE, bool loop = false]) {
     Animation ani = new Animation(name, frames, rate, loop);
     ani.framesLength = framesLength;
     ani.onComplete = onComplete;
@@ -75,12 +76,15 @@ class Animator {
   }
 
   void add(
-      {String name, List frames, int rate = Constant.RATE, bool loop = false}) {
+      {String name = "",
+      List? frames,
+      int rate = Constant.RATE,
+      bool loop = false}) {
     return make(name, frames, rate, loop);
   }
 
   void remove(String name, [bool destroy = false]) {
-    Animation ani = _aniList.getItem(name);
+    Animation? ani = _aniList.getItem(name);
     if (ani != null && destroy) {
       ani.dispose();
     }
@@ -96,7 +100,7 @@ class Animator {
   void update(int time) {
     if (this.status == "stop") return;
 
-    _currentAni.update(time);
+    _currentAni?.update(time);
   }
 
   ////////////////////////////////////////////////////////////
@@ -110,7 +114,6 @@ class Animator {
 
   dispose() {
     this.clear();
-
     onComplete = null;
   }
 }

lib/src/animate/frame.dart

@@ -1,37 +1,36 @@
 import "dart:ui";
-import "dart:math";
 import '../math/point.dart';
 import '../math/mathutil.dart';
 import '../core/constant.dart';
 
 class Frame {
-  Image image;
-  String type;
-  String name;
+  Image? image;
+  String type = "";
+  String name = "";
 
-  Rect srcRect;
-  Rect dstRect;
-  bool trimmed;
-  bool hasClip;
-  Point anchor;
+  Rect? srcRect;
+  Rect? dstRect;
+  bool trimmed = false;
+  bool hasClip = false;
+  Point? anchor;
 
   bool rotated = false;
   bool _setted = false;
 
   dynamic info;
-  Rect get rect => srcRect;
+  Rect? get rect => srcRect;
 
-  Frame([String type, Image img]) {
+  Frame([String type = "", Image? img]) {
     this.type = type;
     this.image = img;
   }
 
   double get width {
-    return this.dstRect != null ? this.dstRect.width : 0;
+    return this.dstRect != null ? this.dstRect!.width : 0;
   }
 
   double get height {
-    return this.dstRect != null ? this.dstRect.height : 0;
+    return this.dstRect != null ? this.dstRect!.height : 0;
   }
 
   bool get isEnabled {
@@ -73,10 +72,10 @@ class Frame {
 
   void rotateDstRectOnce(x, y) {
     if (this._setted != true) {
-      var l = this.dstRect.left;
-      var t = this.dstRect.top;
-      var w = this.dstRect.width;
-      var h = this.dstRect.height;
+      var l = this.dstRect!.left;
+      var t = this.dstRect!.top;
+      var w = this.dstRect!.width;
+      var h = this.dstRect!.height;
 
       List pos = this.coordinateRotate(x, y);
       var x1 = pos[0];
@@ -88,10 +87,10 @@ class Frame {
   }
 
   List coordinateRotate(x, y) {
-    var cx = x;
-    var cy = y;
-    var x0 = y;
-    var y0 = (1 - x);
+    double cx = x;
+    double cy = y;
+    double x0 = y;
+    double y0 = (1.0 - x);
 
     var point = MathUtil.coordinateRotate(-pi / 2, x0, y0, cx, cy);
     var x1 = MathUtil.round(point[0], 4);