hybridgroup/cylon-joystick

#!/usr/bin/env node

"use strict";

var readline = require("readline");

var rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

var gamepad = require("gamepad");

function devices() {
  var dev = [];

  for (var i = 0, l = gamepad.numDevices(); i < l; i++) {
    dev.push(gamepad.deviceAtIndex(i));
  }

  return dev;
}

function printDevices() {
  devices().forEach(function(device) {
    var str = [
      "",
      "  ID:          " + device.deviceID,
      "  Vendor ID:   " + device.vendorID,
      "  Product ID:  " + device.productID,
      "  Description: " + device.description,
      ""
    ].join("\n");

    console.log(str);
  });
}

// apologies for the recursion, but I don't think readline's #question
// implementation supports re-asking for input, so...
function chooseDevice(question, callback) {
  rl.question(question, function(answer) {
    var ids = devices().map(function(d) { return d.deviceID.toString(); });

    if (answer === "?") {
      printDevices();
      return chooseDevice("Which would you like to use? ", callback);
    }

    if (!/^\d+$/.test(answer) || !~ids.indexOf(answer)) {
      console.log("Invalid input.");
      console.log("Enter the ID of the device you'd like to see events for.");
      return chooseDevice("Enter '?' to see available devices. ", callback);
    }

    callback(answer);
    rl.close();
  });
}

// initialize, start polling for events
gamepad.init();
setInterval(gamepad.processEvents, 16);

console.log("Cylon-Joystick Explorer");

if (gamepad.numDevices() === 0) {
  console.log("No SDL-compatible gamepads are currently connected.");
  process.exit();
}

console.log("The current SDL-compatible devices are connected:");

printDevices();

console.log("Which of these devices would you like to see events for?");

chooseDevice("Enter the device's ID now, and hit return/enter: ", function(id) {
  var device = gamepad.deviceAtIndex(id);

  console.log("Listening for events from '" + device.description + "'");

  gamepad.on("move", function (deviceId, axis, value) {
    if (deviceId.toString() !== id) { return; }
    console.log("move", { axis: axis, value: value });
  });

  gamepad.on("up", function (deviceId, num) {
    if (deviceId.toString() !== id) { return; }
    console.log("up", { num: num });
  });

  gamepad.on("down", function (deviceId, num) {
    if (deviceId.toString() !== id) { return; }
    console.log("down", { num: num });
  });
});