chess_interface #

This is a flutter package and doesn't . For dart / backend project, checkout chess_interface_dart Package.

A customizable, feature-rich chess board widget built in Flutter. This package offers a robust foundation for integrating chess gameplay into your Flutter apps — complete with piece rendering, move validation, theming, and more.

Features #

• ♟️ Full chess piece support with images
• ✅ Built-in move validation for all standard piece types
• ♻️ Customizable board themes and piece materials
• 🔄 Supports en passant, castling, and pawn promotion logic
• 📐 Interface-driven board interaction for flexible state management
• 🎨 Material Design color extensions for theming

Getting Started #

Add the package to your pubspec.yaml:

dependencies:
  chess_interface:
    git:
      url: https://github.com/mryadavdilip/chess_interface.git

OR

dependencies:
  chess_interface: ^1.0.8

Then import these:

import 'package:chess_board_widget/chess_board_widget.dart';
import 'package:chess_board_widget/logical_interface/interface.dart';
import 'package:chess_board_widget/models/BoardThemeConfig.dart';

Example #

ChessBoardWidget(
  game: ChessBoardInterface(
    // optional
    fen: 'fen state'
  ),
  
  // optional
  onPromotion: (Position pos) { // pawn position on rank 8
    // Handle promote pawn
  },

  // optional
  onCheckmate: (PieceColor turn) { // Player in checkmate (loosing)
    // Handle checkmate
  }
  
  boardTheme: BoardThemeConfig(
    boardColor: Colors.brown[300],
    materialVariety: 'modern_minimalist', // or check for materialResources.keys in env.dart
  ),
);

Configuration #

Theme Customization #

Customize the board and pieces using BoardThemeConfig. You can define your own colors and piece styles via the asset directory:

BoardThemeConfig(
  boardColor: Colors.green[700],
  materialVariety: 'wooden',
);

Piece Rendering #

The ChessPiece class loads the appropriate asset based on the type, color, and selected material style:

ChessPiece(type: PieceType.queen, color: PieceColor.black)
  .getResource('classic');

Move Validation #

Use MoveValidator.isValidMove() to validate legal chess moves:

bool isValid = MoveValidator.isValidMove(ChessBoardInterface game, Position from, Position to);

It supports:

• All standard chess moves
• Pawn special rules
• Castling logic (including history tracking)
• En passant and double pawn pushes

Arbiter #

Arbiter to handle events like game over, time out and pawn promotion:

And more.. #

File Structure #

• chess_board_widget.dart – Main UI and logic
• move_validator.dart – Move legality checker
• piece.dart – Piece model and asset loader
• arbiter.dart – Game over, timeOut, and promotion handler
• board_theme_config.dart – Customization config
• color_extension.dart – Color manipulation utilities
• interface.dart – Board interaction interface
• env.dart – Environment configuration for materials and colors

Assets #

Ensure your pubspec.yaml declares your assets like so:

flutter:
  assets:
    - assets/classic/pawn.png
    - assets/wooden/king.png

Contributing #

Contributions are welcome! Please open issues and pull requests to help improve this Package.

License #

MIT License. See LICENSE for details.