HeadlessMC Dart

A Dart package that simplifies downloading and running HeadlessMC, allowing you to launch and manage Minecraft servers and clients headlessly.

Features

Download and manage HeadlessMC launcher
Launch Minecraft with various configurations
Support for different Minecraft versions and mod loaders
Process management and interaction
Environment variable management
Headless operation mode (without GUI)

Installation

Add this package to your pubspec.yaml:

dependencies:
  headlessmc_dart: ^0.0.1

Then run:

flutter pub get

Usage

Basic Launch Flow

The basic flow involves setting up a launcher with the proper configuration and then launching Minecraft:

import 'package:headlessmc_dart/headlessmc_dart.dart';

// Initialize the launcher with Java executable and HeadlessMC JAR path
final launcher = HeadlessMCLauncher(
  javaExecutablePath: 'java',
  headlessmcJarPath: '/path/to/headlessmc-launcher-wrapper.jar',
);

// Set up a working directory
launcher.setWorkingDirectory('/path/to/minecraft/directory');

// Configure launch options
final options = LauncherOptions(
  version: '1.20.4',  // Vanilla Minecraft version
  lwjgl: true,        // Enable headless mode
  noOutput: false,    // Show Minecraft output
  commands: true,     // Enable headlessmc-runtime
);

// Launch Minecraft with the configured options
Future<void> launchMinecraft() async {
  try {
    final process = await launcher.launch(options);
    
    // Listen to the output stream
    launcher.onOutput.listen((line) {
      print('Minecraft: $line');
    });
    
    // Wait for the process to exit
    final exitCode = await process.exitCode;
    print('Minecraft exited with code: $exitCode');
  } catch (e) {
    print('Failed to launch Minecraft: $e');
  }
}

Using Mod Loaders

You can launch Minecraft with different mod loaders like Forge or Fabric:

import 'package:headlessmc_dart/headlessmc_dart.dart';

// Create a specific Minecraft version with a mod loader
final forgeVersion = MinecraftVersion(
  baseVersion: '1.20.4',
  modLoader: 'forge',
);

// Convert to string format for launcher options
final versionString = '${forgeVersion.modLoader}:${forgeVersion.baseVersion}';

// Configure launch options with the forge version
final options = LauncherOptions(
  version: versionString,
  lwjgl: true,
  noOutput: false,
  commands: true,
);

// Launch Minecraft with Forge
await launcher.launch(options);

Downloading Libraries

You can use the library downloader to fetch HeadlessMC or other required files:

import 'package:headlessmc_dart/headlessmc_dart.dart';
import 'dart:io';

// Create a downloader for HeadlessMC JAR
final downloader = LibraryDownloader(
  url: 'https://github.com/MCRcortex/headlessmc/releases/download/3.0.0/headlessmc-launcher-wrapper-3.0.0.jar',
  destinationDirectory: '/path/to/download/directory',
  onProgress: (progress) {
    print('Downloaded: ${progress.downloadedBytes} / ${progress.totalBytes} bytes');
    print('Progress: ${progress.percentComplete}%');
  },
  onComplete: (file) {
    print('Download complete: ${file.path}');
  },
);

// Start the download
File downloadedFile = await downloader.download();

Interactive Commands

You can send commands to a running Minecraft instance:

import 'package:headlessmc_dart/headlessmc_dart.dart';

// After launching Minecraft, you can send commands
Future<void> sendMinecraftCommands() async {
  // Send a command to the Minecraft console
  await launcher.sendCommand('/help');
  
  // Wait for a specific output
  final successMessage = await launcher.waitForOutput(
    (line) => line.contains('Loaded'), 
    timeout: Duration(seconds: 30),
  );
  
  if (successMessage != null) {
    print('Server loaded successfully!');
    
    // Send more commands
    await launcher.sendCommand('/op username');
    await launcher.sendCommand('/gamemode creative username');
  }
}

Advanced Configuration with Java Options

You can customize Java options for better performance:

import 'package:headlessmc_dart/headlessmc_dart.dart';

// Configure Java options
launcher.javaOptions
  ..setMaxMemory('4G')            // Set maximum memory
  ..setMinMemory('1G')            // Set minimum memory
  ..addGCOption('-XX:+UseG1GC')   // Use G1 Garbage Collector
  ..addSystemProperty('java.net.preferIPv4Stack', 'true');

// Launch with custom Java options
await launcher.launch(options);

Environment Variables

You can set environment variables for the Minecraft process:

import 'package:headlessmc_dart/headlessmc_dart.dart';

// Set environment variables
launcher.environmentVariables
  ..set('MINECRAFT_OPTS', '-Dfml.queryResult=confirm')
  ..set('JAVA_HOME', '/path/to/java');

// Launch with environment variables
await launcher.launch(options);

License

This package is available under the MIT License.