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flutter timer with increment button
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| import 'package:flutter/material.dart'; | |
| import 'dart:math' as math; | |
| void main() => runApp(MaterialApp( | |
| home: const MyApp(), | |
| theme: ThemeData.dark(), | |
| )); | |
| class MyApp extends StatefulWidget { | |
| const MyApp({Key? key}) : super(key: key); | |
| @override | |
| MyAppState createState() => MyAppState(); | |
| } | |
| class MyAppState extends State<MyApp> with TickerProviderStateMixin { | |
| late AnimationController controller; | |
| late Duration duration; | |
| late TimerPainter painter; | |
| // bool isPlaying = false; | |
| String get timerString { | |
| Duration duration = controller.duration! * controller.value; | |
| return '${duration.inMinutes}:${(duration.inSeconds % 60).toString().padLeft(2, '0')}'; | |
| } | |
| @override | |
| void initState() { | |
| super.initState(); | |
| duration = const Duration(seconds: 10); | |
| controller = AnimationController( | |
| vsync: this, | |
| duration: duration, | |
| ); | |
| painter = TimerPainter( | |
| animation: controller, | |
| backgroundColor: Colors.white, | |
| color: Colors.greenAccent, | |
| ); | |
| } | |
| @override | |
| Widget build(BuildContext context) { | |
| ThemeData themeData = Theme.of(context); | |
| return Scaffold( | |
| body: Padding( | |
| padding: const EdgeInsets.all(8.0), | |
| child: Column( | |
| mainAxisAlignment: MainAxisAlignment.spaceBetween, | |
| children: <Widget>[ | |
| Expanded( | |
| child: Align( | |
| alignment: FractionalOffset.center, | |
| child: AspectRatio( | |
| aspectRatio: 1.0, | |
| child: Stack( | |
| children: <Widget>[ | |
| Positioned.fill( | |
| child: AnimatedBuilder( | |
| animation: controller, | |
| builder: (BuildContext context, Widget? child) { | |
| return CustomPaint(painter: painter); | |
| }, | |
| ), | |
| ), | |
| Align( | |
| alignment: FractionalOffset.center, | |
| child: Column( | |
| mainAxisAlignment: MainAxisAlignment.spaceEvenly, | |
| crossAxisAlignment: CrossAxisAlignment.center, | |
| children: <Widget>[ | |
| Text( | |
| "Count Down", | |
| style: themeData.textTheme.bodyMedium, | |
| ), | |
| AnimatedBuilder( | |
| animation: controller, | |
| builder: (BuildContext context, Widget? child) { | |
| return Text( | |
| timerString, | |
| style: themeData.textTheme.bodyLarge, | |
| ); | |
| }), | |
| ], | |
| ), | |
| ), | |
| ], | |
| ), | |
| ), | |
| ), | |
| ), | |
| Container( | |
| margin: const EdgeInsets.all(8.0), | |
| child: Row( | |
| mainAxisAlignment: MainAxisAlignment.spaceEvenly, | |
| children: <Widget>[ | |
| FloatingActionButton( | |
| child: AnimatedBuilder( | |
| animation: controller, | |
| builder: (BuildContext context, Widget? child) { | |
| return Icon(controller.isAnimating | |
| ? Icons.pause | |
| : Icons.play_arrow); | |
| // Icon(isPlaying | |
| // ? Icons.pause | |
| // : Icons.play_arrow); | |
| }, | |
| ), | |
| onPressed: () { | |
| // setState(() => isPlaying = !isPlaying); | |
| if (controller.isAnimating) { | |
| controller.stop(canceled: true); | |
| } else { | |
| controller.reverse( | |
| from: controller.value == 0.0 | |
| ? 1.0 | |
| : controller.value); | |
| } | |
| }, | |
| ), | |
| FloatingActionButton( | |
| onPressed: () { | |
| setState(() { | |
| var incrValue = 5; | |
| var incrDur = Duration(seconds: incrValue); | |
| // calculate the current duration. | |
| var currentDur = | |
| controller.duration! * controller.value; | |
| // increment the duration by 5 seconds. | |
| var newDur = currentDur + incrDur; | |
| // calculate the total duration of the animation plus the incremented value. | |
| var totalDur = controller.duration! + incrDur; | |
| // calculate the new animation value. | |
| var newValue = newDur.inSeconds / totalDur.inSeconds; | |
| controller.duration = totalDur; | |
| controller.value = newValue; | |
| // Restart Animation. | |
| controller.reverse( | |
| from: controller.value == 0.0 | |
| ? 1.0 | |
| : controller.value); | |
| }); | |
| }, | |
| child: const Icon(Icons.add_alarm), | |
| ) | |
| ], | |
| ), | |
| ) | |
| ], | |
| ), | |
| ), | |
| ); | |
| } | |
| } | |
| class TimerPainter extends CustomPainter { | |
| TimerPainter({ | |
| required this.animation, | |
| required this.backgroundColor, | |
| required this.color, | |
| }) : super(repaint: animation); | |
| final Animation<double> animation; | |
| final Color backgroundColor, color; | |
| @override | |
| void paint(Canvas canvas, Size size) { | |
| Paint paint = Paint() | |
| ..color = backgroundColor | |
| ..strokeWidth = 5.0 | |
| ..strokeCap = StrokeCap.round | |
| ..style = PaintingStyle.stroke; | |
| canvas.drawCircle(size.center(Offset.zero), size.width / 2.0, paint); | |
| paint.color = color; | |
| double progress = (1.0 - animation.value) * 2 * math.pi; | |
| canvas.drawArc(Offset.zero & size, math.pi * 1.5, -progress, false, paint); | |
| } | |
| @override | |
| bool shouldRepaint(TimerPainter oldDelegate) { | |
| return animation.value != oldDelegate.animation.value || | |
| color != oldDelegate.color || | |
| backgroundColor != oldDelegate.backgroundColor; | |
| } | |
| } |
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