M3E Progress Indicator

A Flutter package providing Material 3 Expressive (M3E) standard and wavy progress indicators. It enables smooth determinate progress transitions, scrolling indeterminate waveforms, customizable track end-stops, and wave amplitude morphing for both linear and circular layouts.

---

🎮 Interactive Demo

You can try out the package UI demo here: m3e_core demo

---

🚀 Features

• Linear & Circular Standard Indicators — high-performance standard determinate and indeterminate indicator lines and rings.
• Linear & Circular Wavy Indicators — expressive, wave-shaped indicators that morph into star shapes or scroll horizontally with custom speed.
• Track Gaps and Stops — built-in support for Material 3 design characteristics, including end-stop points and gaps between the progress line and track.
• Smooth Indeterminate Animations — continuous looping waveforms and rotations for loading indicators when no value is provided.
• RTL Support — fully compatible with right-to-left layout directions out of the box.

---

📦 Installation

Add the package to your pubspec.yaml:

dependencies:
  m3e_progress_indicator: ^0.0.2

Import it in your Dart code:

import 'package:m3e_progress_indicator/m3e_progress_indicator.dart';

---

🧩 Quick Start

1. Standard Linear Progress Indicator

A standard Material 3 linear indicator with a customized end-stop and gap size:

M3ELinearProgressIndicator(
  value: 0.7,
  minHeight: 6.0,
  gapSize: 4.0,
  stopSize: 4.0,
)

2. Standard Circular Progress Indicator

A standard circular loading ring. Leave the value as null for an indeterminate animation:

M3ECircularProgressIndicator(
  value: null, // Indeterminate
  strokeWidth: 4.0,
  size: 48.0,
)

3. Wavy Linear Progress Indicator

An expressive linear wave indicator with custom wavelength and scrolling speed:

M3ELinearWavyProgressIndicator(
  value: 0.5,
  strokeWidth: 6.0,
  trackStrokeWidth: 4.0,
  wavelength: 20.0,
  waveSpeed: 15.0,
)

4. Wavy Circular Progress Indicator

An expressive circular wave indicator that bends a sinusoidal path around a circle. Leave value as null for a rotating indeterminate wavy loader:

M3ECircularWavyProgressIndicator(
  value: null, // Indeterminate
  strokeWidth: 5.0,
  wavelength: 18.0,
  waveSpeed: 10.0,
)

---

📖 Detailed API Guide

1. M3ELinearProgressIndicator

Parameter	Type	Default	Description
value	double?	null	Progress value between 0.0 and 1.0. If null, the indicator is indeterminate.
color	Color?	Theme active	Active progress line color.
backgroundColor	Color?	Theme track	Background track color.
minHeight	double	4.0	Height/thickness of the indicator.
strokeCap	StrokeCap	StrokeCap.round	End styling of progress line and track.
gapSize	double	4.0	Gap between the active progress line and track.
stopSize	double	4.0	Size of the end stop indicator on the track.
width	double	double.infinity	Width of the container.

---

2. M3ECircularProgressIndicator

Parameter	Type	Default	Description
value	double?	null	Progress value between 0.0 and 1.0. If null, the indicator is indeterminate.
color	Color?	Theme active	Active progress ring color.
backgroundColor	Color?	Theme track	Background track color.
strokeWidth	double	4.0	Thickness of the active progress path.
strokeCap	StrokeCap	StrokeCap.round	End styling of the progress path.
gapSize	double	4.0	Gap between active progress and track.
size	double	48.0	Height/width diameter of the indicator.

---

3. M3ELinearWavyProgressIndicator

Parameter	Type	Default	Description
value	double?	null	Progress value between 0.0 and 1.0. If null, the indicator is indeterminate.
color	Color?	Theme active	Active waveform color.
backgroundColor	Color?	Theme track	Track color.
strokeWidth	double	4.0	Stroke width of the active wavy line.
trackStrokeWidth	double	3.0	Stroke width of the track.
gapSize	double	4.0	Gap between active progress and track.
stopSize	double	4.0	Size of the end stop indicator on the track.
wavelength	double	24.0	Preferred wavelength of the wave.
waveSpeed	double	24.0	Scrolling speed of the wave in pixels per second.
height	double	20.0	Height of the container layout box.
width	double	240.0	Width of the progress bar.
amplitude	double Function(double)?	Preset	Function returning wave amplitude based on progress.

---

4. M3ECircularWavyProgressIndicator

Parameter	Type	Default	Description
value	double?	null	Progress value between 0.0 and 1.0. If null, the indicator is indeterminate.
color	Color?	Theme active	Active waveform color.
backgroundColor	Color?	Theme track	Track color.
strokeWidth	double	4.0	Stroke width of the active wavy line.
trackStrokeWidth	double	4.0	Stroke width of the track.
gapSize	double	4.0	Gap between active progress and track.
wavelength	double	24.0	Wavelength/frequency spacing of waves on the circle.
waveSpeed	double	24.0	Wave oscillation speed.
size	double	48.0	Diameter size of the circular layout.
amplitude	double Function(double)?	Preset	Function returning wave amplitude based on progress.

---

🐞 Found a bug? or ✨ You have a Feature Request?

Feel free to open an Issue or Contribute to the project.

Hope You Love It!

---

Radhe Radhe 🙏