index.js

var index = require('./package.json');

if (global[index.name] && global[index.name].version === index.version) {
  module.exports = global[index.name];
} else {
  var detection = require('bindings')('detection.node'),
      EventEmitter2 = require('eventemitter2').EventEmitter2;

  var detector = new EventEmitter2({
    wildcard: true,
    delimiter: ':',
    maxListeners: 1000 // default would be 10!
  });

  detector.find = detection.find;

  detection.registerAdded(function(device) {
    detector.emit('add:' + device.vendorId + ':' + device.productId, device);
    detector.emit('add:' + device.vendorId, device);
    detector.emit('add', device);
    detector.emit('change:' + device.vendorId + ':' + device.productId, device);
    detector.emit('change:' + device.vendorId, device);
    detector.emit('change', device);
  });

  detection.registerRemoved(function(device) {
    detector.emit('remove:' + device.vendorId + ':' + device.productId, device);
    detector.emit('remove:' + device.vendorId, device);
    detector.emit('remove', device);
    detector.emit('change:' + device.vendorId + ':' + device.productId, device);
    detector.emit('change:' + device.vendorId, device);
    detector.emit('change', device);
  });

  var started = true;

  detector.startMonitoring = function() {
    if (started) return;

    started = true;
    detection.startMonitoring();
  };

  detector.stopMonitoring = function() {
    if (!started) return;

    started = false;
    detection.stopMonitoring();
  };

  detector.version = index.version;
  global[index.name] = detector;

  module.exports = detector;
}