parallaxj 0.0.1 parallaxj: ^0.0.1 copied to clipboard
A new Flutter project.
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/painting.dart';
import 'package:parallaxj/parallaxj.dart';
import "dart:math";
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'parallaxj Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Stack(
children: [
Center(
child: SizedBox(
width: 200,
height: 400,
child: Parallaxable(
offsetRadio: 1.0 / 10,
under: _underBackground(),
above: _aboveBackground(),
),
),
),
Center(child: SizedBox(width: 300, height: 300, child: Loading())),
],
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
_underBackground() => const SizedBox(
width: 200,
height: 400,
child: Padding(
padding: EdgeInsets.only(top: 123),
child: ColoredBox(
color: Colors.redAccent,
),
),
);
_aboveBackground() => SizedBox(
width: 200,
height: 400,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
SizedBox(
height: 200,
child: Image.asset(
"images/ironman.png",
fit: BoxFit.fitWidth,
)),
const Text("钢铁侠(Iron "
"Man)是美国漫威漫画旗下的超级英雄。有多代钢铁侠,其中最为著名的是托尼·史塔克,初次登场于《悬疑故事》第39期(1963年3月),是斯塔克工业(STARK INDUSTRIES)的CEO")
],
),
));
}
class Loading extends StatefulWidget {
const Loading({Key? key}) : super(key: key);
@override
State<Loading> createState() => _LoadingState();
}
class _LoadingState extends State<Loading> with SingleTickerProviderStateMixin {
late AnimationController _aniController;
@override
void initState() {
super.initState();
_aniController =
AnimationController(vsync: this, duration: const Duration(seconds: 4));
_aniController.repeat();
}
@override
Widget build(BuildContext context) {
return ColoredBox(
color: Colors.black38,
child: AnimatedBuilder(
animation: _aniController,
builder: (BuildContext context, Widget? child) {
return CustomPaint(
painter: LoadingPainter(_aniController.value),
);
},
),
);
}
}
class LoadingPainter extends CustomPainter {
final double progress;
final double dosRadius = 9;
final double gap = 0.1;
final double dosNum = 6;
final Color dosColor = Colors.yellow;
late Paint _paint;
LoadingPainter(this.progress) {
_paint = Paint()
..color = dosColor
..style = PaintingStyle.fill;
}
@override
void paint(Canvas canvas, Size size) {
// (x-a)^2+(y-b)^2=r^2
// x,y = R*cos(θ) , R*sin(θ)
// path of particle
double minSide = min(size.width, size.height);
double particle_radius = minSide / 2 - dosRadius;
for (int i = 0; i < dosNum; i++) {
double begin = 0.5 / (dosNum - 1) * i;
/// 第一个结束 最后一个才开始 耗时都是 a
///
var interval = Interval(begin, begin + 0.5, curve: Curves.slowMiddle);
double angle = -pi / 2 + 2 * pi * interval.transform(progress);
var offset =
Offset(particle_radius * cos(angle), particle_radius * sin(angle));
canvas.drawCircle(
offset.translate(size.width / 2, size.height / 2), dosRadius, _paint);
}
// double angle = 2 * pi * progress;
// var offset =
// Offset(particle_radius * cos(angle), particle_radius * sin(angle));
// canvas.drawCircle(
// offset.translate(size.width / 2, size.height / 2), dosRadius, _paint);
}
@override
bool shouldRepaint(covariant CustomPainter oldDelegate) {
return true;
}
}