Kniffel (Yahtzee) - Java Swing Application

About The Project

This project is a fully functional implementation of the popular dice game Kniffel (Yahtzee), built with Java.

It demonstrates strong Object-Oriented Programming (OOP) principles by separating game logic, rule validation, and user interface. The project features a dual-interface approach: the core logic powers both a classic Console Application and a graphical Desktop GUI built with Java Swing.

Key Features

• Graphical User Interface (GUI): Interactive window with buttons and visual dice representation using javax.swing.
• Complete Ruleset: Implements all standard Kniffel rules (Full House, Straights, Kniffel, Bonus calculations).
• Rule Engine: A dedicated static utility class (KniffelRules) handles complex score validation independently of the UI.
• State Management: Holds logic for re-rolling specific dice and tracking game rounds.

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Architecture

The code is organized into a modular package structure in src/kniffel/.

src/kniffel/
├── Dice.java           # Model: Manages the state of the 5 dice (values, hold status).
├── Scoreboard.java     # Model: Tracks scores for all 13 categories (Upper/Lower section).
├── KniffelRules.java   # Logic: Static Utility class to calculate points (e.g., checks for Full House).
├── KniffelGame.java    # Controller (Console): Runs the text-based version of the game.
└── KniffelVisual.java  # View/Controller (GUI): Runs the Swing-based graphical version.

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Technical Breakdown

• Encapsulation: The Dice class encapsulates the random number generation and the "hold" mechanism, protecting the internal array state.

• Static Logic: KniffelRules contains purely functional static methods (isFullHouse, calculateSum), making the logic testable and reusable for both the Console and GUI versions.

• Event Handling: The GUI utilizes ActionListener inner classes to handle user inputs like rolling dice or selecting categories.

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How to Run

Prerequisites

• Java Development Kit (JDK) 17 or higher installed.

Installation & Execution

1. Clone the repository

git clone [https://github.com/mlrlouis/Kniffel.git](https://github.com/mlrlouis/Kniffel.git)

2. Navigate to the project directory

cd Kniffel

3. Compile the source code

javac -d bin src/kniffel/*.java

6. Run the Game

   • To run the GUI Version (Recommended):

     java -cp bin kniffel.KniffelVisual

   • To run the Console Version:

     java -cp bin kniffel.KniffelGame

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Controls (GUI)

1. Roll Dice: Click to roll. You have 3 rolls per round.

2. Hold Dice: Click "Würfel behalten" and enter the numbers (1-5) of the dice you want to keep (e.g., "1 4 5").

3. Select Category: Choose a scoring category from the dropdown menu and click "Kategorie auswählen" to lock in your score.

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