Simple browser IsActive - periodically emit if a user is active or still active, emit if inactive.

isActive.js

//  var isActive = new IsActive(10000, window);
//  isActive.on('active', function () { console.log('active') });
//  isActive.on('inactive', function () { console.log('inactive') });
//  isActive.start();
var IsActive = function (timerPeriod, g) {

  timerPeriod = parseInt(timerPeriod) || 60000;
  if (!g) g = window;

  var ACTIVE = true,
      INACTIVE = false,
      state = INACTIVE,
      lastActiveTime = 0,
      interval = null,
      self = this;


  var detectActive = function () {
    lastActiveTime = Date.now();

    if (state === INACTIVE) {
      markActive();
      resetInterval();
    }
  }

  var markActive = function () {
    self.emit('active');
    state = ACTIVE;
  }

  var resetInterval = function () {
    clearInterval(interval);

    interval = setInterval(function() {
      if (lastActiveTime > (Date.now() - timerPeriod))
        markActive();
      else {
        if (state === ACTIVE)
          self.emit('inactive');
        state = INACTIVE;
      }
    }, timerPeriod);

  }

  this.start = function () {
    g.document.onclick = detectActive;
    g.document.onmousemove = detectActive;
    g.document.onkeypress = detectActive;
    detectActive();
  }

  self._events = {};

  self.on = function(event, fct){
    self._events[event] = self._events[event] || [];
    self._events[event].push(fct);
  }

  self.emit = function(event /* , args... */){
    if(!self._events[event])  return;
    for(var i = 0; i < self._events[event].length; i++){
      self._events[event][i].apply(self, Array.prototype.slice.call(arguments, 1));
    }
  }
};

// export in common js
if( typeof module !== "undefined" && ('exports' in module)){
  module.exports  = IsActive;
}

what about scroll?