xcat-core/xCAT-UI/js/hoverIntent.js

(function($) {
	/* hoverIntent by Brian Cherne */
	$.fn.hoverIntent = function(f, g) {
		// default configuration options
		var cfg = {
			sensitivity : 7,
			interval : 100,
			timeout : 0
		};
		// override configuration options with user supplied object
		cfg = $.extend(cfg, g ? {
			over : f,
			out : g
		} : f);

		// instantiate variables
		// cX, cY = current X and Y position of mouse, updated by mousemove
		// event
		// pX, pY = previous X and Y position of mouse, set by mouseover and
		// polling interval
		var cX, cY, pX, pY;

		// A private function for getting mouse position
		var track = function(ev) {
			cX = ev.pageX;
			cY = ev.pageY;
		};

		// A private function for comparing current and previous mouse position
		var compare = function(ev, ob) {
			ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
			// compare mouse positions to see if they've crossed the threshold
			if ((Math.abs(pX - cX) + Math.abs(pY - cY)) < cfg.sensitivity) {
				$(ob).unbind("mousemove", track);
				// set hoverIntent state to true (so mouseOut can be called)
				ob.hoverIntent_s = 1;
				return cfg.over.apply(ob, [ ev ]);
			} else {
				// set previous coordinates for next time
				pX = cX;
				pY = cY;
				// use self-calling timeout, guarantees intervals are spaced out
				// properly (avoids JavaScript timer bugs)
				ob.hoverIntent_t = setTimeout(function() {
					compare(ev, ob);
				}, cfg.interval);
			}
		};

		// A private function for delaying the mouseOut function
		var delay = function(ev, ob) {
			ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
			ob.hoverIntent_s = 0;
			return cfg.out.apply(ob, [ ev ]);
		};

		// A private function for handling mouse 'hovering'
		var handleHover = function(e) {
			// next three lines copied from jQuery.hover, ignore children
			// onMouseOver/onMouseOut
			var p = (e.type == "mouseover" ? e.fromElement : e.toElement)
				|| e.relatedTarget;
			while (p && p != this) {
				try {
					p = p.parentNode;
				} catch (e) {
					p = this;
				}
			}
			if (p == this) {
				return false;
			}

			// copy objects to be passed into t (required for event object to be
			// passed in IE)
			var ev = jQuery.extend( {}, e);
			var ob = this;

			// cancel hoverIntent timer if it exists
			if (ob.hoverIntent_t) {
				ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
			}

			// else e.type == "onmouseover"
			if (e.type == "mouseover") {
				// set "previous" X and Y position based on initial entry point
				pX = ev.pageX;
				pY = ev.pageY;
				// update "current" X and Y position based on mousemove
				$(ob).bind("mousemove", track);
				// start polling interval (self-calling timeout) to compare
				// mouse coordinates over time
				if (ob.hoverIntent_s != 1) {
					ob.hoverIntent_t = setTimeout(function() {
						compare(ev, ob);
					}, cfg.interval);
				}

				// else e.type == "onmouseout"
			} else {
				// unbind expensive mousemove event
				$(ob).unbind("mousemove", track);
				// if hoverIntent state is true, then call the mouseOut function
				// after the specified delay
				if (ob.hoverIntent_s == 1) {
					ob.hoverIntent_t = setTimeout(function() {
						delay(ev, ob);
					}, cfg.timeout);
				}
			}
		};

		// bind the function to the two event listeners
		return this.mouseover(handleHover).mouseout(handleHover);
	};

})(jQuery);