detect movable mouse (means a device has movable mouse pointer)

detectMovableMouse.js

(function(){
  
  // over 2 mousemove events fired in 300ms
  var over = 2, period = 300; 

	var count = 0;
	var timer = null;
	   
	var mousemove = function(evt){
		if ( !timer ) {
			timer = setTimeout(function(){
				timer = null;
				count = 0;
			}, period);
			return;
		}
		if ( ++count < over ) {
			return;
		}
		document.removeEventListener('mousemove', mousemove);
		window.movableMouse = true;
		document.documentElement.classList.add('movableMouse');
		fireEvt();
	};

	var fireEvt = function(){
		var evt = document.createEvent('HTMLEvents');
		evt.initEvent('movableMouse', false, false);
		document.dispatchEvent(evt);
	};

	window.movableMouse = false;
	document.addEventListener('mousemove', mousemove);

})();