Dimengen — Flutter Dimensions Generator

Dimengen is a powerful code generator for Flutter that automatically creates EdgeInsets, BorderRadius, and SizedBox constants based on your predefined dimension values.

It helps you centralize spacing and size values, improve UI consistency, and boost code readability and maintainability.

Getting Started

Define your dimension constants inside an annotated class:

import 'package:dimengen/dimengen.dart';

@Dimengen()
abstract final class Dimensions {
  static const double s = 8.0;
  static const double m = 16.0;
  static const double l = 24.0;
}

This generates constants like:

• Insets.m → EdgeInsets.all(16)
• Borders.sTopLeft → BorderRadius.only(topLeft: Radius.circular(8))
• Spaces.mVertical → SizedBox(height: 16)

Example usage:

Container(
  padding: Insets.m,
  margin: Insets.m,
  decoration: BoxDecoration(
    borderRadius: Borders.sTopLeft,
    color: Colors.blue.shade100,
  ),
  child: Column(
    children: [
      Text('Design Dimensions'),
      Spaces.mVertical,
      Text('M: ${Dimensions.m}'),
      Spaces.h(Dimensions.m),
    ],
  ),
)

Modular Generation

Need only specific dimensions? Use separate annotations:

Example with @Spacegen:

import 'package:dimengen/dimengen.dart';

part 'spaces.g.dart';

@Spacegen()
abstract class _Spaces {
  _Spaces._();

  static const double m = 24.0;
}

Generates:

abstract class Spaces {
  const Spaces._();

  static const SizedBox m = SizedBox.square(dimension: 24.0);
  static const SizedBox mVertical = SizedBox(height: 24.0);
  static const SizedBox mHorizontal = SizedBox(width: 24.0);

  static SizedBox h(double value) => SizedBox(height: value);
  static SizedBox w(double value) => SizedBox(width: value);
}

Customization

Customize the generated class names and control what is generated:

@Dimengen(
  spacesName: 'DesignSpaces',
  generateInsets: false,
)

// or

@Spacegen(name: 'Gaps')

Installation

Add to your pubspec.yaml:

dart pub add dimengen

and build_runner as dev dependencies

dart pub add --dev build_runner

⸻

Code Generation

Build once:

flutter pub run build_runner build

Watch for changes:

flutter pub run build_runner watch

⸻

Why Use Dimengen?

• 📐 Centralized dimension values
• ♻️ Reusable and consistent UI spacing
• ⚡ Auto-generates dozens of variants
• 👀 Enhances code clarity and maintainability

Contributing

Have suggestions, ideas, or found a bug? Contributions are welcome! Open an issue or submit a pull request — we’d love to hear from you.