valkryst/vcontroller

A helper library for JInput which makes it easy to automatically poll for controller input, connection, and disconnection events and notify listeners when they occur.

VController is a helper library for JInput with the following features:

• Automatic polling of controller input events VIA ControllerPoller.
• Automatic detection of controller connection and disconnection events VIA HotSwapPoller.
  • As JInput does not natively support hot-swapping, this library uses a polling approach to detect it. The downside to this approach is that JInput may print messages to System.err on every poll.
  • This will cause a resource leak on Windows. A solution is being discussed here.
    • To mitigate this issue, I suggest only enabling the HotSwapPoller when showing the user a list of controllers to select from. Reducing the polling rate will also help as each poll creates a "dead" thread which takes up system resources.
• Interfaces to listen to controller and hot-swap events VIA ControllerListener and HotSwapListener.

This library assumes that you have already properly configured JInput and that it is working.

Table of Contents

• Installation
  • Gradle
  • Maven
  • sbt
• Example
  • Controller Polling
  • Hot Swap Polling

Installation

VController is hosted on the JitPack package repository which supports Gradle, Maven, and sbt.

Gradle

Add JitPack to your build.gradle at the end of repositories.

allprojects {
	repositories {
		...
		maven { url 'https://jitpack.io' }
	}
}

Add VController as a dependency.

dependencies {
	implementation 'com.github.Valkryst:VController:2023.10.26'
}

Maven

Add JitPack as a repository.

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

Add VController as a dependency.

<dependency>
    <groupId>com.github.Valkryst</groupId>
    <artifactId>VController</artifactId>
    <version>2023.10.26</version>
</dependency>

Scala SBT

Add JitPack as a resolver.

resolvers += "jitpack" at "https://jitpack.io"

Add VController as a dependency.

libraryDependencies += "com.github.Valkryst" % "VController" % "2023.10.26"

Example

Controller Polling

This example prompts you to select a controller, then it continuously polls the controller for events and prints them to the console.

import net.java.games.input.Controller;
import net.java.games.input.ControllerEnvironment;

import java.util.Scanner;

public class ControllerExample {
    public static void main(String[] args) {
        final var controllerPoller = new ControllerPoller(getController());
        controllerPoller.addListener(event -> {
            final var component = event.getComponent();
            System.out.println(component.getName());
            System.out.println(component.getIdentifier());
            System.out.println(component.getDeadZone());
            System.out.println(component.getPollData());
            System.out.println();
        });
        controllerPoller.start(16);

        System.out.println("\nPolling for events. Try moving the controller's joysticks and pressing its buttons.");
    }

    private static ControllerEnvironment getEnvironment() {
        final var environment = ControllerEnvironment.getDefaultEnvironment();

        if (!environment.isSupported()) {
            throw new IllegalStateException("Controller environment is not supported.");
        }

        return environment;
    }

    private static Controller getController() {
        final var environment = getEnvironment();
        final var controllers = environment.getControllers();

        System.out.println("Detected Controllers");
        for (int i = 0 ; i < controllers.length ; i++) {
            System.out.println("\t" + i + ": " + controllers[i].getName());
        }

        System.out.print("\nEnter a number to select a controller: ");
        final var scanner = new Scanner(System.in);
        final var index = scanner.nextInt();
        System.out.println("\nYou selected: " + controllers[index].getName());

        return controllers[index];
    }
}

Hot Swap Polling

This example prints a message to the console when a controller is connected or disconnected.

import net.java.games.input.Controller;

public class HotSwapExample {
    public static void main(final String[] args) {
        final var hotswapPoller = HotSwapPoller.getInstance();
        hotswapPoller.addListener(new HotSwapListener() {
            @Override
            public void controllerAdded(Controller controller) {
                System.out.println("Added: " + controller.getName());
            }

            @Override
            public void controllerRemoved(Controller controller) {
                System.out.println("Removed: " + controller.getName());
            }
        });

        hotswapPoller.start();

        System.out.println("Polling for hot-swaps. Try adding or removing a controller.");
    }
}

Credits & Inspiration

• litiengine

vcontroller's Issues

Lower minimum Java version

Could you perhaps lower the Java version to something lower like the oldest supported JDK for example? I want to use the library for a large repo but can't because we're still on 17.

Memory leak

There's a memory leak somewhere, the RAM usage climbs to about 1.6 GB after around 40 minutes and all the connected devices get lost.