I needed an event for a “long press” with the mouse, or a “long touch” event on the mobile devices. This one does the following:

• depends on jQuery
• prevents the “click” event from firing, in case the “longpress” event occurs
• “longpress” does not fire if the mouse leaves the element during pressing
• the following examples attaches to all elements specified by the selector

(function( selector ){
	var $ = ( typeof jQuery !== 'undefined' )  ?  jQuery  :  false;
	if( !$ ) return;


	var isLongClick = false,
		isMouseIn = false,
		pressTimer,
		pressDelay = 1000; // ms

	$(selector)
		.on( 'mousedown touchstart', function(e){
			var $this = $(this);

			pressTimer = window.setTimeout(function() {
				if( typeof e.button !== 'undefined'  &&  e.button !== 0 ) return;  // prevent trigger on right-click
				if( isMouseIn ){  
					isLongClick = true;
					$this.trigger( 'longpress' );
					e.preventDefault();
					e.stopPropagation();
					e.stopImmediatePropagation();
				}
			}, pressDelay);

		} )
		.on( 'mouseup touchend', function(e){
			clearTimeout(pressTimer);
		} )
		.on( 'click', function(e){
			if( isLongClick ){
				isLongClick = false; // reset this flag (it has done its part)
				e.preventDefault();
				e.stopPropagation();
    			e.stopImmediatePropagation();
    			return false;
			}
		} )
		.on( 'mouseover touchstart', function(e){
			isMouseIn = true;
		} )
		.on( 'mouseout touchleave touchcancel', function(e){
			isMouseIn = false;
		} )
	;
})( '.btn' );