Industrial Drawing Flutter 🎨 #

A high-performance, production-ready vector drawing engine for Flutter. Designed for industrial applications, engineering tools, and creative whiteboards. Built with a modular architecture that separates the rendering engine from the UI.

✨ Features #

• 🛠 Precision Tools: Line, Rectangle, Circle, Triangle, and Freehand drawing.
• 📏 Measurement Mode: Built-in distance and dimension calculation.
• 🔄 State Management: Robust Undo/Redo stack with historical state snapshots.
• 📱 Hardware Accelerated: Optimized CustomPainter rendering with RepaintBoundary support.
• 💾 Persistence: Native support for exporting to PNG and serializing to JSON for cloud storage.
• 🔍 Infinite Canvas: Support for smooth Pan and Zoom (Scale) interactions.
• 📐 Shape Snapping: Intelligent alignment and snapping for technical accuracy.

🏗 Architecture #

This package follows a Senior Package Maintainer architecture to ensure 130+ pub points and maximum reusability:

lib/
├── drawing_engine.dart         # Public API (Barrel file)
└── src/
    ├── controllers/            # DrawingController (Business Logic)
    ├── models/                 # Immutable Data Models (DrawnShape)
    ├── painters/               # Pure CustomPainter Logic
    └── widgets/                # DrawingCanvas (Presentation Layer)

🚀 Getting Started #

1. Installation #

Add this to your pubspec.yaml:

dependencies:
  industrial_drawing_flutter:
    path: ./ # Or latest version from pub.dev

2. Basic Usage #

import 'package:industrial_drawing_flutter/drawing_engine.dart';

// 1. Initialize the Controller
final controller = DrawingController();

// 2. Add the Canvas to your UI
DrawingCanvas(
  controller: controller,
  showGrid: true,
)

// 3. Control drawing programmatically
controller.currentTool = DrawingTool.draw;
controller.currentShapeType = ShapeType.rectangle;
controller.undo();

🔧 Controller API #

The DrawingController is the brain of your application:

🛠 Design Decisions (Senior Reviewer Focus) #

• Headless Logic: All drawing calculations are performed in the DrawingController, allowing you to write unit tests without needing a UI.
• Lazy Repainting: The DrawingPainter only repaints when necessary to preserve battery and performance on mobile devices.
• Immutable Models: DrawnShape objects are immutable clones during undo/redo to prevent side effects.

📄 License #

This project is licensed under the MIT License - see the LICENSE file for details.

🤝 Contributing #

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request