flutter_oknob - Dart API docs

Overview:

Description: | The FlutterKnob widget provides a customizable rotary knob that can be used for various controls, such as adjusting volume, brightness, or any other value within a specified range. This widget is interactive, supports various styling options, and provides smooth performance, making it suitable for a variety of applications.

Features:

Interactive Control: Allows users to drag and adjust values in a specified range.
Customizable Appearance: Support for size, color, gradients, sensitivity, and more.
Value Tracking: Emits changes through the onChanged callback for external handling.
Optional Label: Allows display of a custom label beneath the knob for added context.
Smooth Performance: Optimized for smooth interaction and visual updates.

Dependencies:

Flutter SDK (ensure that your project is configured to use Flutter 3.0 or above).

Installation:

steps: - Add the FlutterKnob widget to your Flutter project dependencies in your pubspec.yaml file. - Import the widget into your Dart file using the following import statement:

  import 'import 'package:flutter_knob/flutter_oldschool_knob.dart';


  dependencies:
    flutter_oknob: ^0.0.3

Usage Example:

Description: | Here is an example of how to use the FlutterOKnob widget in your Flutter application. The widget supports customizable properties such as size, gradients, marker color, sensitivity, and a custom label.

Example:

    FlutterOKnob(
      value: 50.0,
      onChanged: (newValue) {
        print('Knob value changed: $newValue');
      },
      size: 200.0,
      minValue: 0.0,
      maxValue: 100.0,
      outerRingGradient: LinearGradient(
        colors: [Colors.blue, Colors.purple],
      ),
      innerKnobGradient: LinearGradient(
        colors: [Colors.orange, Colors.red],
      ),
      markerColor: Colors.green,
      knobLabel: Text(
        'Volume',
        style: TextStyle(color: Colors.white, fontSize: 18.0),
      ),
    );

Parameters:

Description: | The following table outlines the customizable parameters that control the behavior and appearance of the FlutterOKnob widget. Each parameter has a default value, but all can be modified to fit the needs of your specific implementation.

parameters:

 value:
    type: double
    description: |
      The current value of the knob, which should be between the `minValue` and `maxValue`. It is required for the widget to work properly.
    required: true
  onChanged:
    type: ValueChanged<double>
    description: |
      A callback function that is triggered when the knob's value changes. It passes the new value as an argument.
    required: true
  size:
    type: double
    default: 150.0
    description: |
      The diameter of the knob (in pixels). This determines the size of the knob on the screen.
  minValue:
    type: double
    default: 0.0
    description: |
      The minimum possible value that the knob can be set to.
  maxValue:
    type: double
    default: 100.0
    description: |
      The maximum possible value that the knob can be set to.
  markerColor:
    type: Color
    default: Colors.greenAccent
    description: |
      The color of the marker that indicates the current value on the knob.
  outerRingGradient:
    type: Gradient
    default: |
      LinearGradient(colors: [Colors.black, Colors.grey], begin: Alignment.topLeft, end: Alignment.bottomRight)
    description: |
      The gradient applied to the outer ring of the knob.
  innerKnobGradient:
    type: Gradient
    default: |
      LinearGradient(colors: [Colors.grey, Colors.black], begin: Alignment.topLeft, end: Alignment.bottomRight)
    description: |
      The gradient applied to the inner knob.
  sensitivity:
    type: double
    default: 0.5
    description: |
      Controls how sensitive the knob is to user input during drag gestures. Higher values make the knob more sensitive.
  knobLabel:
    type: Widget
    default: null
    description: |
      An optional widget that can be placed beneath the knob. Typically used to display a label, such as "Volume" or "Brightness."

How It Works:

Description: | The FlutterOKnob widget works by listening to drag gestures (onPanUpdate). When a user drags the knob, the value of the knob changes based on the drag movement. The updated value is clamped between minValue and maxValue, ensuring it stays within the allowed range. The value change is reflected visually by updating the ValueNotifier which triggers the widget to rebuild and display the new value.

The widget also uses custom painting (`FlutterKnobPainter`) to render the knob's outer ring, inner knob, and value marker. This allows the widget to provide a smooth, customizable appearance while maintaining high performance.

Customization Options:

description: | The FlutterOKnob widget provides several options to customize its appearance and behavior. These options allow you to tailor the widget to fit your app’s design and functional needs.

options: outerRingGradient: description: | You can customize the outer ring's gradient to match your app's theme. example: | outerRingGradient: LinearGradient( colors: Colors.blue, Colors.cyan, ) innerKnobGradient: description: | The inner knob's gradient can also be customized to fit your design. example: | innerKnobGradient: LinearGradient( colors: Colors.orange, Colors.yellow, ) markerColor: description: | Change the color of the marker that indicates the current value on the knob. example: | markerColor: Colors.red sensitivity: description: | Adjust the knob's sensitivity to user gestures. example: | sensitivity: 0.8 knobLabel: description: | Add a custom widget as the label below the knob. This could be useful for showing a label like "Volume" or any other text. example: | knobLabel: Text( 'Volume', style: TextStyle(color: Colors.white, fontSize: 16), )

Notes:

Ensure that the initial value (value) is within the range defined by minValue and maxValue to avoid unexpected behavior.
For better UI consistency, customize the gradients, sensitivity, and marker color to match the design of your app.
The widget is responsive and adapts to different screen resolutions.

Contribution:

description: | If you'd like to contribute or report issues, feel free to open a pull request or an issue on the repository. Contributions such as bug fixes, performance improvements, and feature requests are always welcome.

License:

license: MIT description: | This project is licensed under the MIT License. See the LICENSE file for details.

FlutterOKnob Widget Documentation