flutter_dial

Description:

flutter dial

A Flutter package implementing a Dial for input and visual display.
Features #
A Dial begins as an image with a transparent background (png, gif, tiff).
In order to maintain any image skeuomorphism, the image is not rotated.
A visual rotation indicator provides feedback on dial position.
When a Dial is selected via tap, a translucent control ring becomes visible
and can be manipulated via rotation. The color(s), width, and opacity of the
control ring are programmable. A Dial cannot be manipulated if not selected.
The control ring may have a single color, or be colored with a cold/hot
color gradient.
A Dial is deselected with a second tap. In addition, Dials are focusable
widgets. When other focusable widgets (including Dials) are selected,
the previous Dial will deselect to avoid input errors.
A Dial can have infinite range on [0.0, 360] degrees, or it can
be programmed to have a fixed number of evenly placed radial stops.
A callback closure function onDialed() exposes the current rotational value
of the Dial in the form of current (degrees, percent, stop number) of rotation.
Persistence is available via Dial.value as initial state, and the percent
value from the Dial.onDialed() callback for current state.
When a Dial receives or loses focus, Dial.onFocusChange() will be called. This
allows programming of effects external to the Dial (eg, highlighting, bolding) on
associated Widgets.
A dial controlling a meter: #

This demonstrates:

tap to focus/defocus
dialing
responsive output on the meter

When the Dial has focus, the meter will "light up" when indicating the dials position.
Several dials with outputs monitored on simulated LED displays: #

This demonstrates:

Automatic focus change between the Dials
LED panels indicating the active Dial by brightness
Different colored Dial control rings
Two Dials with radial stops
One Dial infinitely adjustable between 0 and 100 percent
A "washing machine" style cold/hot control ring indicating increasing percentage

Getting started #


Add a dependency in pubspec.yaml:
flutter_dial: ^any


Import into your appropriate implementation dart files:
import 'package:flutter_dial/flutter_dial.dart'


Use Dial(size, ringWidth, color, image, ...) widget(s) as required.


Usage #
The Flutter "Counter" example Stateful Widget rewritten to use a Dial.
Assumption: a suitable image is in the /assets/images folder.
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});

final String title;

@override
State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
int _position = 0;

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text('Dial setting:'),
Text('$_position', style: Theme.of(context).textTheme.headlineMedium),
const SizedBox(height: 40),
Dial(
value: 0.0,
image: Image.asset('assets/images/my_dial.png'),
size: 200,
ringWidth: 50,
stopCount: 10,
color: Colors.teal,
indicatorColor: Colors.black,
opacity: 0.5,
onDial: (degrees, percent, stopNumber) => setState(() => _position = stopNumber),
),
],
),
),
);
}
}

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Additional information #
Source repository:
https://github.com/beleniak/flutter_dial
The example in the repository contains a free-to-use sample dial image.