A customizable circular slider for Flutter

flutter_circular_slider

A customizable circular slider for Flutter.

Installation

Add

flutter_circular_slider : ^lastest_version

to your pubspec.yaml, and run

flutter packages get

in your project's root directory.

Basic Usage

Create a new project with command

flutter create myapp

Edit lib/main.dart like this:

import 'package:flutter/material.dart';

import 'package:flutter_circular_slider/flutter_circular_slider.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        backgroundColor: Colors.blueGrey,
        body: Center(
          child: Container(child: DoubleCircularSlider(100, 0, 20)),
        ));
  }
}

There are two different options:

• SingleCircularSlider: has only one handler and can be moved either dragging the handler or just by clicking on different parts of the slider.
• DoubleCircularSlider: has two handlers and both have to be moved by dragging them.

Constructor

Parameter	Default	Description
divisions		The number of sections in which the circle will be divided for selection.
init		(Only for DoubleCircularSlider) The initial value in the selection. Has to be bigger than 0 and smaller than divisions.
end		(Only for DoubleCircularSlider) The end value in the selection. Has to be bigger than 0 and smaller than divisions.
position		(Only for SingleCircularSlider) The selection. Has to be bigger than 0 and smaller than divisions.
height	220.0	Height of the canvas where the slider is rendered.
width	220.0	Width of the canvas where the slider is rendered.
primarySectors	0	Number of sectors painted in the base circle. Painted in selectionColor.
secondarySectors	0	Number of secondary sectors painted in the base circle. Painted in baseColor.
child	null	Widget that will be inserted in the center of the circular slider.
onSelectionChange	void onSelectionChange(int init, int end)	Triggered every time the user interacts with the slider and changes the init and end values.
baseColor	Color.fromRGBO(255, 255, 255, 0.1)	The color used for the base of the circle.
selectionColor	Color.fromRGBO(255, 255, 255, 0.3)	The color used for the selection in the circle.
handlerColor	Colors.white	The color used for the handlers.
handlerOutterRadius	12.0	The radius for the outter circle around the handler.

Use Cases

Sleep Time Selection

import 'dart:math';

import 'package:flutter/material.dart';

import 'package:flutter_circular_slider/flutter_circular_slider.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: SafeArea(
      child: Container(
          decoration: BoxDecoration(
            image: DecorationImage(
              image: AssetImage('images/background_morning.png'),
              fit: BoxFit.cover,
            ),
          ),
          child: SleepPage()),
    ));
  }
}

class SleepPage extends StatefulWidget {
  @override
  _SleepPageState createState() => _SleepPageState();
}

class _SleepPageState extends State<SleepPage> {
  final baseColor = Color.fromRGBO(255, 255, 255, 0.3);

  int initTime;
  int endTime;

  int inBedTime;
  int outBedTime;

  @override
  void initState() {
    super.initState();
    _shuffle();
  }

  void _shuffle() {
    setState(() {
      initTime = _generateRandomTime();
      endTime = _generateRandomTime();
      inBedTime = initTime;
      outBedTime = endTime;
    });
  }

  void _updateLabels(int init, int end) {
    setState(() {
      inBedTime = init;
      outBedTime = end;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        Text(
          'How long did you stay in bed?',
          style: TextStyle(color: Colors.white),
        ),
        CircularSlider(
          288,
          initTime,
          endTime,
          height: 220.0,
          width: 220.0,
          baseColor: Color.fromRGBO(255, 255, 255, 0.1),
          selectionColor: baseColor,
          handlerColor: Colors.white,
          handlerOutterRadius: 12.0,
          onSelectionChange: _updateLabels,
          child: Padding(
            padding: const EdgeInsets.all(12.0),
            child: Center(
                child: Text('${_formatIntervalTime(inBedTime, outBedTime)}',
                    style: TextStyle(fontSize: 36.0, color: Colors.white))),
          ),
        ),
        Row(mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: [
          _formatBedTime('IN THE', inBedTime),
          _formatBedTime('OUT OF', outBedTime),
        ]),
        FlatButton(
          child: Text('S H U F F L E'),
          color: baseColor,
          textColor: Colors.white,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(50.0),
          ),
          onPressed: _shuffle,
        ),
      ],
    );
  }

  Widget _formatBedTime(String pre, int time) {
    return Column(
      children: [
        Text(pre, style: TextStyle(color: baseColor)),
        Text('BED AT', style: TextStyle(color: baseColor)),
        Text(
          '${_formatTime(time)}',
          style: TextStyle(color: Colors.white),
        )
      ],
    );
  }

  String _formatTime(int time) {
    if (time == 0 || time == null) {
      return '00:00';
    }
    var hours = time ~/ 12;
    var minutes = (time % 12) * 5;
    return '$hours:$minutes';
  }

  String _formatIntervalTime(int init, int end) {
    var sleepTime = end > init ? end - init : 288 - init + end;
    var hours = sleepTime ~/ 12;
    var minutes = (sleepTime % 12) * 5;
    return '${hours}h${minutes}m';
  }

  int _generateRandomTime() => Random().nextInt(288);
}

GitHub

https://github.com/davidanaya/flutter-circular-slider