Offline Java Based Chess Game

A clean, easy-to-read Java implementation of chess with a minimal Swing GUI intended for a college project. The code focuses on clarity and correctness for core chess rules and is easy to extend.

Important: This project uses only Java and Swing for the frontend.

Features

• Full object-oriented board & piece model (Pawn, Knight, Bishop, Rook, Queen, King).
• Pseudo-legal move generation per piece plus filtering into legal moves (moves that would leave the king in check are rejected).
• Castling, pawn promotion, check, checkmate and stalemate detection.
• Swing-based GUI with:
  • Click-to-select and click-to-move interaction.
  • Visual highlights (selected square, legal moves, last move).
  • Larger piece icons rendered from Unicode glyphs for good visibility on light/dark squares.
  • Move history and simple status area.
• Clean code structure suitable for study and extension.

Limitations / Known omissions

• En-passant is intentionally left out (not implemented).
• Draw rules not implemented: fifty-move rule, threefold repetition, and insufficient material detection.
• No AI engine — two-player local play only.
• Promotion choices are offered via a dialog in the GUI; move-generation currently treats promotion at apply-time (the GUI prompts the user).

Project layout

• src/chess/Main.java — application entry point.
• src/chess/model — board, pieces, move, move generator and game state:
  • Board.java
  • Piece.java (+ Pawn, Knight, Bishop, Rook, Queen, King)
  • Move.java
  • MoveGenerator.java
  • GameState.java
• src/chess/ui — Swing UI:
  • ChessGUI.java

Build & run (command-line)

On Unix-like systems (Linux, macOS) with JDK installed:

1. Compile: javac -d out $(find src -name "*.java")

2. Run: java -cp out chess.Main

On Windows (PowerShell / CMD), a simple alternative:

1. Create output directory: mkdir out
2. Compile (PowerShell): Get-ChildItem -Recurse -Filter *.java | ForEach-Object { & javac -d out $_.FullName }
3. Run: java -cp out chess.Main

Notes:

• You can also import the src directory into an IDE (IntelliJ IDEA, Eclipse, NetBeans) as a plain Java project and run Main from the IDE.
• No external libraries are required.

UI Notes / Customization

• The GUI uses Unicode chess glyphs rendered into image icons so pieces are large and visible on both light and dark squares.
• To tweak square size, edit ChessGUI.squareSize (default 80).
• If you see a compilation error related to Color, it's likely a name conflict between java.awt.Color and the project's chess.model.Color. The GUI fully-qualifies java.awt.Color and chess.model.Color where needed; avoid wildcard imports that might re-introduce ambiguity.

Testing & Debugging tips

• If you encounter an infinite recursion / StackOverflowError while running, ensure Board.isSquareAttacked does not call piece.legalMoves() — attack detection must use direct attack logic to avoid recursion with King.castling checks. The shipped Board implementation uses direct attack checks.
• Add unit tests to validate:
  • Castling rights in various board states.
  • Promotion behavior.
  • Check/checkmate/stalemate patterns.
  • Pinning and discovered checks.

Packaging

To produce a runnable JAR (optional):

1. Compile into out as above.
2. Create manifest (e.g., manifest.txt) with: Main-Class: chess.Main
3. Package: jar cfm chess.jar manifest.txt -C out .

Run: java -jar chess.jar

Contributing

This project is intended as a one time college project. If you'd like to contribute:

• Fork and submit a PR with focused changes (e.g., en-passant implementation, tests, UI improvements).
• Keep changes modular and include tests when appropriate.

Contact / Attribution

Project built for a college assignment. If you need help extending features (en-passant, engine, tests, UI polish), describe what you'd like and include any failing behavior or error traces — happy to help.