update

lib/beesight.dart

@@ -1,4 +1,5 @@
 import 'dart:math';
+import 'dart:ui' as ui;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/animation.dart';
@@ -18,7 +19,10 @@ class _DemoPageState extends State<DemoPage> {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      body: new DemoBody(screenSize: MediaQuery.of(context).size),
+      body: new Container(
+        margin: const EdgeInsets.all(50.0),
+        child: new DemoBody(screenSize: MediaQuery.of(context).size),
+      ),
     );
   }
 }
@@ -36,12 +40,30 @@ class DemoBody extends StatefulWidget {
 
 class _DemoBodyState extends State<DemoBody> with TickerProviderStateMixin {
   AnimationController animationController;
+  CharacterFactory characterFactory;
 
   @override
   void initState() {
     super.initState();
     animationController = new AnimationController(
         vsync: this, duration: new Duration(seconds: 2));
+
+    characterFactory = new CharacterFactory();
+
+    animationController.addListener(() {
+      characterFactory.addPoint(animationController.value);
+    });
+
+    animationController.addStatusListener((status) {
+      if (status == AnimationStatus.completed) {
+        characterFactory.step++;
+        animationController.reverse();
+      } else if (status == AnimationStatus.dismissed) {
+        characterFactory.step++;
+        animationController.forward();
+      }
+    });
+    animationController.forward();
   }
 
   @override
@@ -61,7 +83,10 @@ class _DemoBodyState extends State<DemoBody> with TickerProviderStateMixin {
         ),
         builder: (context, child) => new CustomPaint(
               size: widget.screenSize,
-              painter: new _DemoPainter(widget.screenSize),
+              painter: new _DemoPainter(
+                widget.screenSize,
+                characterFactory.offsetPoints,
+              ),
             ),
       ),
     );
@@ -70,18 +95,70 @@ class _DemoBodyState extends State<DemoBody> with TickerProviderStateMixin {
 
 class _DemoPainter extends CustomPainter {
   final Size screenSize;
+  final List<Offset> offsetPoints;
   Paint painter;
 
-  _DemoPainter(this.screenSize) {
+  _DemoPainter(this.screenSize, this.offsetPoints) {
     painter = new Paint()
       ..strokeWidth = 1.0
       ..color = Colors.red
       ..style = PaintingStyle.stroke;
   }
 
   @override
-  void paint(Canvas canvas, Size size) {}
+  void paint(Canvas canvas, Size size) {
+    canvas.drawPoints(ui.PointMode.polygon, offsetPoints, painter);
+    if (offsetPoints.length > 0) {
+      canvas.drawCircle(offsetPoints[offsetPoints.length - 1], 10.0, painter);
+    }
+  }
 
   @override
   bool shouldRepaint(_DemoPainter oldDelegate) => true;
 }
+
+class CharacterFactory {
+  List<Offset> offsetPoints = [];
+  int step = 0;
+
+  Offset getQuadraticBezier(List<Offset> offsetList, double t) {
+    return getQuadraticBezier2(offsetList, t, 0, offsetList.length - 1);
+  }
+
+  Offset getQuadraticBezier2(List<Offset> offsetList, double t, int i, int j) {
+    if (i == j) return offsetList[i];
+
+    Offset b0 = getQuadraticBezier2(offsetList, t, i, j - 1);
+    Offset b1 = getQuadraticBezier2(offsetList, t, i + 1, j);
+    Offset res =
+        new Offset((1 - t) * b0.dx + t * b1.dx, (1 - t) * b0.dy + t * b1.dy);
+    return res;
+  }
+
+  void addPoint(double time) {
+    if (step == 0) {
+      offsetPoints.add(bCharStep1(time));
+    } else if (step == 1) {
+      offsetPoints.add(bCharStep2(time));
+    } else {
+      step = 0;
+      offsetPoints.clear();
+    }
+  }
+
+  Offset bCharStep1(double time) {
+    return getQuadraticBezier([
+      new Offset(0.0, 100.0),
+      new Offset(0.0, 200.0),
+    ], time);
+  }
+
+  Offset bCharStep2(double time) {
+    return getQuadraticBezier([
+      new Offset(0.0, 175.0),
+      new Offset(35.0, 112.0),
+      new Offset(100.0, 212.0),
+      new Offset(0.0, 200.0),
+    ], time);
+  }
+}

lib/main.dart

@@ -5,14 +5,10 @@ import 'package:flutter/material.dart';
 //import 'demo2.dart';
 //import 'demo3.dart';
 import 'beesight.dart';
-import 'dartpros.dart';
 
 void main() => runApp(new MyApp());
 
 class MyApp extends StatelessWidget {
-  MyApp() {
-    new April.origin()..getOdd()..printString();
-  }
 
   @override
   Widget build(BuildContext context) {