/**
 * $Id: jtip.js 28281 2008-08-26 15:21:31Z jed $
 *
 * Adapted from jtip by Cody Lindley.  The only things left from the original are the styles and divs, plus some of the
 * location calculations.  Everything else has been reworked to pull the tip data from an "em" element following the
 * link rather than parsing the href attribute for a request param that was used for an AJAX request to load the tip
 * data.
 * $Author: jed $
 * $Revision: 28281 $ $Date: 2008-08-26 11:21:31 -0400 (Tue, 26 Aug 2008) $
 */
$(initTips);

/**
 * Registers hover functions with all links whose class is "jtip"
 */
function initTips()
{
	$("a.jtip").hover(function() { showTip(this); }, removeTip);
}

/**
 * Displays the tip over the given link.  Tip text is retrieved from the next "em" element after the link.
 * @param link a link that needs a tooltip
 */
function showTip(link)
{
	var tip = $(link).next("em").text();
	if (tip !== undefined)
	{
		var left = renderTip(link);
		$('#JT').css({left: left + "px", top: computeTop(link) + "px"});
		$('#JT_copy').text(tip);
		$('#JT').show();
	}
}

/**
 * Renders the tip over the given link by appending the tip div to the body and computing the
 * left position of the tip for later use.
 * @param link a link
 * @return the left position of the tip, to be dynamically plugged into the CSS for the tip
 */
function renderTip(link)
{
	var tipWidth = 250;
	var element = document.documentElement;
	var width = self.innerWidth || (element && element.clientWidth) || document.body.clientWidth;
	var leftOffset = width - getAbsoluteLeft(link.id);
	var left;

	if (leftOffset > (tipWidth + 75))
	{
		$("body").append("<div id='JT' style='width:" + tipWidth
					+ "px'><div id='JT_arrow_left'></div><div id='JT_close_left'>"
					+ "</div><div id='JT_copy'><div class='JT_loader'><div></div></div>");//right side
		var arrowOffset = link.offsetWidth + 11;
		left = getAbsoluteLeft(link.id) + arrowOffset; //set x position
	}
	else
	{
		$("body").append("<div id='JT' style='width:" + tipWidth
					+ "px'><div id='JT_arrow_right' style='left:" + (tipWidth + 1)
					+ "px'></div><div id='JT_close_right'>"
					+ "</div><div id='JT_copy'><div class='JT_loader'><div></div></div>");//left side
		left = getAbsoluteLeft(link.id) - (tipWidth + 15); //set x position
	}

	return left;
}

/**
 * Computes the top of the tooltip based on the given link
 * @param link a link
 * @return the top position of the tooltip, to be dynamically plugged into the CSS for the tip
 */
function computeTop(link)
{
	return getAbsoluteTop(link.id) - 3;
}

/**
 * Computes the left position of an object from the upper left viewport corner
 * @param objectId the ID of the object
 * @return the left position of the object with <code>objectId</code>
 */
function getAbsoluteLeft(objectId)
{
	var element = document.getElementById(objectId);
	var left = element.offsetLeft;
	while (element.offsetParent != null)
	{
		var parent = element.offsetParent;
		left += parent.offsetLeft;
		element = parent;
	}

	return left;
}

/**
 * Computes the top position of an object from the upper left viewport corner
 * @param objectId the ID of the object
 * @return the top position of the object with <code>objectId</code>
 */
function getAbsoluteTop(objectId)
{
	var element = document.getElementById(objectId);
	var top = element.offsetTop;
	while (element.offsetParent != null)
	{
		var parent = element.offsetParent;
		top += parent.offsetTop;
		element = parent;
	}

	return top;
}

/**
 * Removes the tip from the DOM.
 */
function removeTip()
{
	$('#JT').remove();
}