$(document).ready(function(){
	
	// generateSprites arguments: 
	// 1st - parent class (the main class on the parent ul), with preceding period
	// 2nd - selected prefix (eg. for a selected class of "selected-about", use "selected-" as the value)
	// 3rd - :active state toggle, set to true if you've defined :active states (and the jQuery equivalent) in your CSS
	// 4th - animation speed, in milliseconds (eg. 300 = 0.3 seconds)
	// 5th - animation style, as a string. Set to "slide" or "fade" (defaults to "fade")
	
	// example usage:
	// generateSprites(".navigation", "selected-", true, 300, "fade");
	// generateSprites(".top-nav", "position-", true, 200, "slide");
	// generateSprites(".sidebar-nav", "current-", false, 150, "fade");

	
	generateSprites(".nav", "current-", true, 300, "fade");

});

function generateSprites(parent, selectedPrefix, setActive, hoverSpeed, style) {
	// throw the parent object's class into a variable
	var parentClass = $(parent).attr("class");

	// start a loop that cycles through each of the li elements inside the parent element
	$(parent).children("li").each(function() {
		// create a few variables that we'll need during this function:
		// myClass = the class of the object we're currently inspecting
		// current = what the selected class should look like for the parent of the object we're currently inspecting
		var myClass = ($(this).attr("class"))
		var current = parent.substring(1) + " current-" + ($(this).attr("class"));

		// turn on nav events for element this loop identifies
		attachNavEvents(parent, myClass, setActive, hoverSpeed, style);
	
		// let's hide the CSS-defined background image, but only if this isn't the currently-selected item
		if (parentClass != current) {
			$(this).children("a").css({backgroundImage:"none"});
		}

	});
}


function attachNavEvents(parent, myClass, setActive, hoverSpeed, style) {
	$(parent + " ." + myClass).mouseover(function() {
		// create pseudo-link
		$(this).append('<div class="nav-' + myClass + '"></div>');
		// either slide or fade, depending on the style value
		if (style == "slide") {
			// slide down the pseudo-link
			$("div.nav-" + myClass).css({display:"none"}).slideDown(hoverSpeed);
		} else {
			// fade in the pseudo-link
			$("div.nav-" + myClass).css({display:"none"}).fadeIn(hoverSpeed);
		}
	}).mouseout(function() {
		// either slide or fade, depending on the style value
		if (style == "slide") {
			// slide up & destroy pseudo-link
			$("div.nav-" + myClass).slideUp(hoverSpeed, function() {
				$(this).remove();
			});
		} else {
			// fade out & destroy pseudo-link
			$("div.nav-" + myClass).fadeOut(hoverSpeed, function() {
				$(this).remove();
			});
		}
	});


	// we only want to check the mousedown/up events if the CSS exists for :active states
	// if so, let's apply our selective filtering to undo the events above
	if (setActive) {
		$(parent + " ." + myClass).mousedown(function() {
			$("div.nav-" + myClass).attr("class", "nav-" + myClass + "-click");
		}).mouseup(function() {
			$("div.nav-" + myClass + "-click").attr("class", "nav-" + myClass);
		});
	}
}