path: root/jquery/jquery.powertip-1.2.0.js

/*!
 PowerTip - v1.2.0 - 2013-04-03
 http://stevenbenner.github.com/jquery-powertip/
 Copyright (c) 2013 Steven Benner (http://stevenbenner.com/).
 Released under MIT license.
 https://raw.github.com/stevenbenner/jquery-powertip/master/LICENSE.txt
*/
(function(factory) {
	if (typeof define === 'function' && define.amd) {
		// AMD. Register as an anonymous module.
		define(['jquery'], factory);
	} else {
		// Browser globals
		factory(jQuery);
	}
}(function($) {

	// useful private variables
	var $document = $(document),
		$window = $(window),
		$body = $('body');

	// constants
	var DATA_DISPLAYCONTROLLER = 'displayController',
		DATA_HASACTIVEHOVER = 'hasActiveHover',
		DATA_FORCEDOPEN = 'forcedOpen',
		DATA_HASMOUSEMOVE = 'hasMouseMove',
		DATA_MOUSEONTOTIP = 'mouseOnToPopup',
		DATA_ORIGINALTITLE = 'originalTitle',
		DATA_POWERTIP = 'powertip',
		DATA_POWERTIPJQ = 'powertipjq',
		DATA_POWERTIPTARGET = 'powertiptarget',
		RAD2DEG = 180 / Math.PI;

	/**
	 * Session data
	 * Private properties global to all powerTip instances
	 */
	var session = {
		isTipOpen: false,
		isFixedTipOpen: false,
		isClosing: false,
		tipOpenImminent: false,
		activeHover: null,
		currentX: 0,
		currentY: 0,
		previousX: 0,
		previousY: 0,
		desyncTimeout: null,
		mouseTrackingActive: false,
		delayInProgress: false,
		windowWidth: 0,
		windowHeight: 0,
		scrollTop: 0,
		scrollLeft: 0
	};

	/**
	 * Collision enumeration
	 * @enum {number}
	 */
	var Collision = {
		none: 0,
		top: 1,
		bottom: 2,
		left: 4,
		right: 8
	};

	/**
	 * Display hover tooltips on the matched elements.
	 * @param {(Object|string)} opts The options object to use for the plugin, or
	 *     the name of a method to invoke on the first matched element.
	 * @param {*=} [arg] Argument for an invoked method (optional).
	 * @return {jQuery} jQuery object for the matched selectors.
	 */
	$.fn.powerTip = function(opts, arg) {
		// don't do any work if there were no matched elements
		if (!this.length) {
			return this;
		}

		// handle api method calls on the plugin, e.g. powerTip('hide')
		if ($.type(opts) === 'string' && $.powerTip[opts]) {
			return $.powerTip[opts].call(this, this, arg);
		}

		// extend options and instantiate TooltipController
		var options = $.extend({}, $.fn.powerTip.defaults, opts),
			tipController = new TooltipController(options);

		// hook mouse and viewport dimension tracking
		initTracking();

		// setup the elements
		this.each(function elementSetup() {
			var $this = $(this),
				dataPowertip = $this.data(DATA_POWERTIP),
				dataElem = $this.data(DATA_POWERTIPJQ),
				dataTarget = $this.data(DATA_POWERTIPTARGET),
				title;

			// handle repeated powerTip calls on the same element by destroying the
			// original instance hooked to it and replacing it with this call
			if ($this.data(DATA_DISPLAYCONTROLLER)) {
				$.powerTip.destroy($this);
			}

			// attempt to use title attribute text if there is no data-powertip,
			// data-powertipjq or data-powertiptarget. If we do use the title
			// attribute, delete the attribute so the browser will not show it
			title = $this.attr('title');
			if (!dataPowertip && !dataTarget && !dataElem && title) {
				$this.data(DATA_POWERTIP, title);
				$this.data(DATA_ORIGINALTITLE, title);
				$this.removeAttr('title');
			}

			// create hover controllers for each element
			$this.data(
				DATA_DISPLAYCONTROLLER,
				new DisplayController($this, options, tipController)
			);
		});

		// attach events to matched elements if the manual options is not enabled
		if (!options.manual) {
			this.on({
				// mouse events
				'mouseenter.powertip': function elementMouseEnter(event) {
					$.powerTip.show(this, event);
				},
				'mouseleave.powertip': function elementMouseLeave() {
					$.powerTip.hide(this);
				},
				// keyboard events
				'focus.powertip': function elementFocus() {
					$.powerTip.show(this);
				},
				'blur.powertip': function elementBlur() {
					$.powerTip.hide(this, true);
				},
				'keydown.powertip': function elementKeyDown(event) {
					// close tooltip when the escape key is pressed
					if (event.keyCode === 27) {
						$.powerTip.hide(this, true);
					}
				}
			});
		}

		return this;
	};

	/**
	 * Default options for the powerTip plugin.
	 */
	$.fn.powerTip.defaults = {
		fadeInTime: 200,
		fadeOutTime: 100,
		followMouse: false,
		popupId: 'powerTip',
		intentSensitivity: 7,
		intentPollInterval: 100,
		closeDelay: 100,
		placement: 'n',
		smartPlacement: false,
		offset: 10,
		mouseOnToPopup: false,
		manual: false
	};

	/**
	 * Default smart placement priority lists.
	 * The first item in the array is the highest priority, the last is the lowest.
	 * The last item is also the default, which will be used if all previous options
	 * do not fit.
	 */
	$.fn.powerTip.smartPlacementLists = {
		n: ['n', 'ne', 'nw', 's'],
		e: ['e', 'ne', 'se', 'w', 'nw', 'sw', 'n', 's', 'e'],
		s: ['s', 'se', 'sw', 'n'],
		w: ['w', 'nw', 'sw', 'e', 'ne', 'se', 'n', 's', 'w'],
		nw: ['nw', 'w', 'sw', 'n', 's', 'se', 'nw'],
		ne: ['ne', 'e', 'se', 'n', 's', 'sw', 'ne'],
		sw: ['sw', 'w', 'nw', 's', 'n', 'ne', 'sw'],
		se: ['se', 'e', 'ne', 's', 'n', 'nw', 'se'],
		'nw-alt': ['nw-alt', 'n', 'ne-alt', 'sw-alt', 's', 'se-alt', 'w', 'e'],
		'ne-alt': ['ne-alt', 'n', 'nw-alt', 'se-alt', 's', 'sw-alt', 'e', 'w'],
		'sw-alt': ['sw-alt', 's', 'se-alt', 'nw-alt', 'n', 'ne-alt', 'w', 'e'],
		'se-alt': ['se-alt', 's', 'sw-alt', 'ne-alt', 'n', 'nw-alt', 'e', 'w']
	};

	/**
	 * Public API
	 */
	$.powerTip = {
		/**
		 * Attempts to show the tooltip for the specified element.
		 * @param {jQuery|Element} element The element to open the tooltip for.
		 * @param {jQuery.Event=} event jQuery event for hover intent and mouse
		 *     tracking (optional).
		 */
		show: function apiShowTip(element, event) {
			if (event) {
				trackMouse(event);
				session.previousX = event.pageX;
				session.previousY = event.pageY;
				$(element).data(DATA_DISPLAYCONTROLLER).show();
			} else {
				$(element).first().data(DATA_DISPLAYCONTROLLER).show(true, true);
			}
			return element;
		},

		/**
		 * Repositions the tooltip on the element.
		 * @param {jQuery|Element} element The element the tooltip is shown for.
		 */
		reposition: function apiResetPosition(element) {
			$(element).first().data(DATA_DISPLAYCONTROLLER).resetPosition();
			return element;
		},

		/**
		 * Attempts to close any open tooltips.
		 * @param {(jQuery|Element)=} element The element with the tooltip that
		 *     should be closed (optional).
		 * @param {boolean=} immediate Disable close delay (optional).
		 */
		hide: function apiCloseTip(element, immediate) {
			if (element) {
				$(element).first().data(DATA_DISPLAYCONTROLLER).hide(immediate);
			} else {
				if (session.activeHover) {
					session.activeHover.data(DATA_DISPLAYCONTROLLER).hide(true);
				}
			}
			return element;
		},

		/**
		 * Destroy and roll back any powerTip() instance on the specified element.
		 * @param {jQuery|Element} element The element with the powerTip instance.
		 */
		destroy: function apiDestroy(element) {
			$(element).off('.powertip').each(function destroy() {
				var $this = $(this),
					dataAttributes = [
						DATA_ORIGINALTITLE,
						DATA_DISPLAYCONTROLLER,
						DATA_HASACTIVEHOVER,
						DATA_FORCEDOPEN
					];

				if ($this.data(DATA_ORIGINALTITLE)) {
					$this.attr('title', $this.data(DATA_ORIGINALTITLE));
					dataAttributes.push(DATA_POWERTIP);
				}

				$this.removeData(dataAttributes);
			});
			return element;
		}
	};

	// API aliasing
	$.powerTip.showTip = $.powerTip.show;
	$.powerTip.closeTip = $.powerTip.hide;

	/**
	 * Creates a new CSSCoordinates object.
	 * @private
	 * @constructor
	 */
	function CSSCoordinates() {
		var me = this;

		// initialize object properties
		me.top = 'auto';
		me.left = 'auto';
		me.right = 'auto';
		me.bottom = 'auto';

		/**
		 * Set a property to a value.
		 * @private
		 * @param {string} property The name of the property.
		 * @param {number} value The value of the property.
		 */
		me.set = function(property, value) {
			if ($.isNumeric(value)) {
				me[property] = Math.round(value);
			}
		};
	}

	/**
	 * Creates a new tooltip display controller.
	 * @private
	 * @constructor
	 * @param {jQuery} element The element that this controller will handle.
	 * @param {Object} options Options object containing settings.
	 * @param {TooltipController} tipController The TooltipController object for
	 *     this instance.
	 */
	function DisplayController(element, options, tipController) {
		var hoverTimer = null;

		/**
		 * Begins the process of showing a tooltip.
		 * @private
		 * @param {boolean=} immediate Skip intent testing (optional).
		 * @param {boolean=} forceOpen Ignore cursor position and force tooltip to
		 *     open (optional).
		 */
		function openTooltip(immediate, forceOpen) {
			cancelTimer();
			if (!element.data(DATA_HASACTIVEHOVER)) {
				if (!immediate) {
					session.tipOpenImminent = true;
					hoverTimer = setTimeout(
						function intentDelay() {
							hoverTimer = null;
							checkForIntent();
						},
						options.intentPollInterval
					);
				} else {
					if (forceOpen) {
						element.data(DATA_FORCEDOPEN, true);
					}
					tipController.showTip(element);
				}
			}
		}

		/**
		 * Begins the process of closing a tooltip.
		 * @private
		 * @param {boolean=} disableDelay Disable close delay (optional).
		 */
		function closeTooltip(disableDelay) {
			cancelTimer();
			session.tipOpenImminent = false;
			if (element.data(DATA_HASACTIVEHOVER)) {
				element.data(DATA_FORCEDOPEN, false);
				if (!disableDelay) {
					session.delayInProgress = true;
					hoverTimer = setTimeout(
						function closeDelay() {
							hoverTimer = null;
							tipController.hideTip(element);
							session.delayInProgress = false;
						},
						options.closeDelay
					);
				} else {
					tipController.hideTip(element);
				}
			}
		}

		/**
		 * Checks mouse position to make sure that the user intended to hover on the
		 * specified element before showing the tooltip.
		 * @private
		 */
		function checkForIntent() {
			// calculate mouse position difference
			var xDifference = Math.abs(session.previousX - session.currentX),
				yDifference = Math.abs(session.previousY - session.currentY),
				totalDifference = xDifference + yDifference;

			// check if difference has passed the sensitivity threshold
			if (totalDifference < options.intentSensitivity) {
				tipController.showTip(element);
			} else {
				// try again
				session.previousX = session.currentX;
				session.previousY = session.currentY;
				openTooltip();
			}
		}

		/**
		 * Cancels active hover timer.
		 * @private
		 */
		function cancelTimer() {
			hoverTimer = clearTimeout(hoverTimer);
			session.delayInProgress = false;
		}

		/**
		 * Repositions the tooltip on this element.
		 * @private
		 */
		function repositionTooltip() {
			tipController.resetPosition(element);
		}

		// expose the methods
		this.show = openTooltip;
		this.hide = closeTooltip;
		this.cancel = cancelTimer;
		this.resetPosition = repositionTooltip;
	}

	/**
	 * Creates a new Placement Calculator.
	 * @private
	 * @constructor
	 */
	function PlacementCalculator() {
		/**
		 * Compute the CSS position to display a tooltip at the specified placement
		 * relative to the specified element.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 * @param {string} placement The placement for the tooltip.
		 * @param {number} tipWidth Width of the tooltip element in pixels.
		 * @param {number} tipHeight Height of the tooltip element in pixels.
		 * @param {number} offset Distance to offset tooltips in pixels.
		 * @return {CSSCoordinates} A CSSCoordinates object with the position.
		 */
		function computePlacementCoords(element, placement, tipWidth, tipHeight, offset) {
			var placementBase = placement.split('-')[0], // ignore 'alt' for corners
				coords = new CSSCoordinates(),
				position;

			if (isSvgElement(element)) {
				position = getSvgPlacement(element, placementBase);
			} else {
				position = getHtmlPlacement(element, placementBase);
			}

			// calculate the appropriate x and y position in the document
			switch (placement) {
			case 'n':
				coords.set('left', position.left - (tipWidth / 2));
				coords.set('bottom', session.windowHeight - position.top + offset);
				break;
			case 'e':
				coords.set('left', position.left + offset);
				coords.set('top', position.top - (tipHeight / 2));
				break;
			case 's':
				coords.set('left', position.left - (tipWidth / 2));
				coords.set('top', position.top + offset);
				break;
			case 'w':
				coords.set('top', position.top - (tipHeight / 2));
				coords.set('right', session.windowWidth - position.left + offset);
				break;
			case 'nw':
				coords.set('bottom', session.windowHeight - position.top + offset);
				coords.set('right', session.windowWidth - position.left - 20);
				break;
			case 'nw-alt':
				coords.set('left', position.left);
				coords.set('bottom', session.windowHeight - position.top + offset);
				break;
			case 'ne':
				coords.set('left', position.left - 20);
				coords.set('bottom', session.windowHeight - position.top + offset);
				break;
			case 'ne-alt':
				coords.set('bottom', session.windowHeight - position.top + offset);
				coords.set('right', session.windowWidth - position.left);
				break;
			case 'sw':
				coords.set('top', position.top + offset);
				coords.set('right', session.windowWidth - position.left - 20);
				break;
			case 'sw-alt':
				coords.set('left', position.left);
				coords.set('top', position.top + offset);
				break;
			case 'se':
				coords.set('left', position.left - 20);
				coords.set('top', position.top + offset);
				break;
			case 'se-alt':
				coords.set('top', position.top + offset);
				coords.set('right', session.windowWidth - position.left);
				break;
			}

			return coords;
		}

		/**
		 * Finds the tooltip attachment point in the document for a HTML DOM element
		 * for the specified placement.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 * @param {string} placement The placement for the tooltip.
		 * @return {Object} An object with the top,left position values.
		 */
		function getHtmlPlacement(element, placement) {
			var objectOffset = element.offset(),
				objectWidth = element.outerWidth(),
				objectHeight = element.outerHeight(),
				left,
				top;

			// calculate the appropriate x and y position in the document
			switch (placement) {
			case 'n':
				left = objectOffset.left + objectWidth / 2;
				top = objectOffset.top;
				break;
			case 'e':
				left = objectOffset.left + objectWidth;
				top = objectOffset.top + objectHeight / 2;
				break;
			case 's':
				left = objectOffset.left + objectWidth / 2;
				top = objectOffset.top + objectHeight;
				break;
			case 'w':
				left = objectOffset.left;
				top = objectOffset.top + objectHeight / 2;
				break;
			case 'nw':
				left = objectOffset.left;
				top = objectOffset.top;
				break;
			case 'ne':
				left = objectOffset.left + objectWidth;
				top = objectOffset.top;
				break;
			case 'sw':
				left = objectOffset.left;
				top = objectOffset.top + objectHeight;
				break;
			case 'se':
				left = objectOffset.left + objectWidth;
				top = objectOffset.top + objectHeight;
				break;
			}

			return {
				top: top,
				left: left
			};
		}

		/**
		 * Finds the tooltip attachment point in the document for a SVG element for
		 * the specified placement.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 * @param {string} placement The placement for the tooltip.
		 * @return {Object} An object with the top,left position values.
		 */
		function getSvgPlacement(element, placement) {
			var svgElement = element.closest('svg')[0],
				domElement = element[0],
				point = svgElement.createSVGPoint(),
				boundingBox = domElement.getBBox(),
				matrix = domElement.getScreenCTM(),
				halfWidth = boundingBox.width / 2,
				halfHeight = boundingBox.height / 2,
				placements = [],
				placementKeys = ['nw', 'n', 'ne', 'e', 'se', 's', 'sw', 'w'],
				coords,
				rotation,
				steps,
				x;

			function pushPlacement() {
				placements.push(point.matrixTransform(matrix));
			}

			// get bounding box corners and midpoints
			point.x = boundingBox.x;
			point.y = boundingBox.y;
			pushPlacement();
			point.x += halfWidth;
			pushPlacement();
			point.x += halfWidth;
			pushPlacement();
			point.y += halfHeight;
			pushPlacement();
			point.y += halfHeight;
			pushPlacement();
			point.x -= halfWidth;
			pushPlacement();
			point.x -= halfWidth;
			pushPlacement();
			point.y -= halfHeight;
			pushPlacement();

			// determine rotation
			if (placements[0].y !== placements[1].y || placements[0].x !== placements[7].x) {
				rotation = Math.atan2(matrix.b, matrix.a) * RAD2DEG;
				steps = Math.ceil(((rotation % 360) - 22.5) / 45);
				if (steps < 1) {
					steps += 8;
				}
				while (steps--) {
					placementKeys.push(placementKeys.shift());
				}
			}

			// find placement
			for (x = 0; x < placements.length; x++) {
				if (placementKeys[x] === placement) {
					coords = placements[x];
					break;
				}
			}

			return {
				top: coords.y + session.scrollTop,
				left: coords.x + session.scrollLeft
			};
		}

		// expose methods
		this.compute = computePlacementCoords;
	}

	/**
	 * Creates a new tooltip controller.
	 * @private
	 * @constructor
	 * @param {Object} options Options object containing settings.
	 */
	function TooltipController(options) {
		var placementCalculator = new PlacementCalculator(),
			tipElement = $('#' + options.popupId);

		// build and append tooltip div if it does not already exist
		if (tipElement.length === 0) {
			tipElement = $('<div/>', { id: options.popupId });
			// grab body element if it was not populated when the script loaded
			// note: this hack exists solely for jsfiddle support
			if ($body.length === 0) {
				$body = $('body');
			}
			$body.append(tipElement);
		}

		// hook mousemove for cursor follow tooltips
		if (options.followMouse) {
			// only one positionTipOnCursor hook per tooltip element, please
			if (!tipElement.data(DATA_HASMOUSEMOVE)) {
				$document.on('mousemove', positionTipOnCursor);
				$window.on('scroll', positionTipOnCursor);
				tipElement.data(DATA_HASMOUSEMOVE, true);
			}
		}

		// if we want to be able to mouse onto the tooltip then we need to attach
		// hover events to the tooltip that will cancel a close request on hover and
		// start a new close request on mouseleave
		if (options.mouseOnToPopup) {
			tipElement.on({
				mouseenter: function tipMouseEnter() {
					// we only let the mouse stay on the tooltip if it is set to let
					// users interact with it
					if (tipElement.data(DATA_MOUSEONTOTIP)) {
						// check activeHover in case the mouse cursor entered the
						// tooltip during the fadeOut and close cycle
						if (session.activeHover) {
							session.activeHover.data(DATA_DISPLAYCONTROLLER).cancel();
						}
					}
				},
				mouseleave: function tipMouseLeave() {
					// check activeHover in case the mouse cursor entered the
					// tooltip during the fadeOut and close cycle
					if (session.activeHover) {
						session.activeHover.data(DATA_DISPLAYCONTROLLER).hide();
					}
				}
			});
		}

		/**
		 * Gives the specified element the active-hover state and queues up the
		 * showTip function.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 */
		function beginShowTip(element) {
			element.data(DATA_HASACTIVEHOVER, true);
			// show tooltip, asap
			tipElement.queue(function queueTipInit(next) {
				showTip(element);
				next();
			});
		}

		/**
		 * Shows the tooltip, as soon as possible.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 */
		function showTip(element) {
			var tipContent;

			// it is possible, especially with keyboard navigation, to move on to
			// another element with a tooltip during the queue to get to this point
			// in the code. if that happens then we need to not proceed or we may
			// have the fadeout callback for the last tooltip execute immediately
			// after this code runs, causing bugs.
			if (!element.data(DATA_HASACTIVEHOVER)) {
				return;
			}

			// if the tooltip is open and we got asked to open another one then the
			// old one is still in its fadeOut cycle, so wait and try again
			if (session.isTipOpen) {
				if (!session.isClosing) {
					hideTip(session.activeHover);
				}
				tipElement.delay(100).queue(function queueTipAgain(next) {
					showTip(element);
					next();
				});
				return;
			}

			// trigger powerTipPreRender event
			element.trigger('powerTipPreRender');

			// set tooltip content
			tipContent = getTooltipContent(element);
			if (tipContent) {
				tipElement.empty().append(tipContent);
			} else {
				// we have no content to display, give up
				return;
			}

			// trigger powerTipRender event
			element.trigger('powerTipRender');

			session.activeHover = element;
			session.isTipOpen = true;

			tipElement.data(DATA_MOUSEONTOTIP, options.mouseOnToPopup);

			// set tooltip position
			if (!options.followMouse) {
				positionTipOnElement(element);
				session.isFixedTipOpen = true;
			} else {
				positionTipOnCursor();
			}

			// fadein
			tipElement.fadeIn(options.fadeInTime, function fadeInCallback() {
				// start desync polling
				if (!session.desyncTimeout) {
					session.desyncTimeout = setInterval(closeDesyncedTip, 500);
				}

				// trigger powerTipOpen event
				element.trigger('powerTipOpen');
			});
		}

		/**
		 * Hides the tooltip.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 */
		function hideTip(element) {
			// reset session
			session.isClosing = true;
			session.activeHover = null;
			session.isTipOpen = false;

			// stop desync polling
			session.desyncTimeout = clearInterval(session.desyncTimeout);

			// reset element state
			element.data(DATA_HASACTIVEHOVER, false);
			element.data(DATA_FORCEDOPEN, false);

			// fade out
			tipElement.fadeOut(options.fadeOutTime, function fadeOutCallback() {
				var coords = new CSSCoordinates();

				// reset session and tooltip element
				session.isClosing = false;
				session.isFixedTipOpen = false;
				tipElement.removeClass();

				// support mouse-follow and fixed position tips at the same time by
				// moving the tooltip to the last cursor location after it is hidden
				coords.set('top', session.currentY + options.offset);
				coords.set('left', session.currentX + options.offset);
				tipElement.css(coords);

				// trigger powerTipClose event
				element.trigger('powerTipClose');
			});
		}

		/**
		 * Moves the tooltip to the users mouse cursor.
		 * @private
		 */
		function positionTipOnCursor() {
			// to support having fixed tooltips on the same page as cursor tooltips,
			// where both instances are referencing the same tooltip element, we
			// need to keep track of the mouse position constantly, but we should
			// only set the tip location if a fixed tip is not currently open, a tip
			// open is imminent or active, and the tooltip element in question does
			// have a mouse-follow using it.
			if (!session.isFixedTipOpen && (session.isTipOpen || (session.tipOpenImminent && tipElement.data(DATA_HASMOUSEMOVE)))) {
				// grab measurements
				var tipWidth = tipElement.outerWidth(),
					tipHeight = tipElement.outerHeight(),
					coords = new CSSCoordinates(),
					collisions,
					collisionCount;

				// grab collisions
				coords.set('top', session.currentY + options.offset);
				coords.set('left', session.currentX + options.offset);
				collisions = getViewportCollisions(
					coords,
					tipWidth,
					tipHeight
				);

				// handle tooltip view port collisions
				if (collisions !== Collision.none) {
					collisionCount = countFlags(collisions);
					if (collisionCount === 1) {
						// if there is only one collision (bottom or right) then
						// simply constrain the tooltip to the view port
						if (collisions === Collision.right) {
							coords.set('left', session.windowWidth - tipWidth);
						} else if (collisions === Collision.bottom) {
							coords.set('top', session.scrollTop + session.windowHeight - tipHeight);
						}
					} else {
						// if the tooltip has more than one collision then it is
						// trapped in the corner and should be flipped to get it out
						// of the users way
						coords.set('left', session.currentX - tipWidth - options.offset);
						coords.set('top', session.currentY - tipHeight - options.offset);
					}
				}

				// position the tooltip
				tipElement.css(coords);
			}
		}

		/**
		 * Sets the tooltip to the correct position relative to the specified target
		 * element. Based on options settings.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 */
		function positionTipOnElement(element) {
			var priorityList,
				finalPlacement;

			if (options.smartPlacement) {
				priorityList = $.fn.powerTip.smartPlacementLists[options.placement];

				// iterate over the priority list and use the first placement option
				// that does not collide with the view port. if they all collide
				// then the last placement in the list will be used.
				$.each(priorityList, function(idx, pos) {
					// place tooltip and find collisions
					var collisions = getViewportCollisions(
						placeTooltip(element, pos),
						tipElement.outerWidth(),
						tipElement.outerHeight()
					);

					// update the final placement variable
					finalPlacement = pos;

					// break if there were no collisions
					if (collisions === Collision.none) {
						return false;
					}
				});
			} else {
				// if we're not going to use the smart placement feature then just
				// compute the coordinates and do it
				placeTooltip(element, options.placement);
				finalPlacement = options.placement;
			}

			// add placement as class for CSS arrows
			tipElement.addClass(finalPlacement);
		}

		/**
		 * Sets the tooltip position to the appropriate values to show the tip at
		 * the specified placement. This function will iterate and test the tooltip
		 * to support elastic tooltips.
		 * @private
		 * @param {jQuery} element The element that the tooltip should target.
		 * @param {string} placement The placement for the tooltip.
		 * @return {CSSCoordinates} A CSSCoordinates object with the top, left, and
		 *     right position values.
		 */
		function placeTooltip(element, placement) {
			var iterationCount = 0,
				tipWidth,
				tipHeight,
				coords = new CSSCoordinates();

			// set the tip to 0,0 to get the full expanded width
			coords.set('top', 0);
			coords.set('left', 0);
			tipElement.css(coords);

			// to support elastic tooltips we need to check for a change in the
			// rendered dimensions after the tooltip has been positioned
			do {
				// grab the current tip dimensions
				tipWidth = tipElement.outerWidth();
				tipHeight = tipElement.outerHeight();

				// get placement coordinates
				coords = placementCalculator.compute(
					element,
					placement,
					tipWidth,
					tipHeight,
					options.offset
				);

				// place the tooltip
				tipElement.css(coords);
			} while (
				// sanity check: limit to 5 iterations, and...
				++iterationCount <= 5 &&
				// try again if the dimensions changed after placement
				(tipWidth !== tipElement.outerWidth() || tipHeight !== tipElement.outerHeight())
			);

			return coords;
		}

		/**
		 * Checks for a tooltip desync and closes the tooltip if one occurs.
		 * @private
		 */
		function closeDesyncedTip() {
			var isDesynced = false;
			// It is possible for the mouse cursor to leave an element without
			// firing the mouseleave or blur event. This most commonly happens when
			// the element is disabled under mouse cursor. If this happens it will
			// result in a desynced tooltip because the tooltip was never asked to
			// close. So we should periodically check for a desync situation and
			// close the tip if such a situation arises.
			if (session.isTipOpen && !session.isClosing && !session.delayInProgress) {
				// user moused onto another tip or active hover is disabled
				if (session.activeHover.data(DATA_HASACTIVEHOVER) === false || session.activeHover.is(':disabled')) {
					isDesynced = true;
				} else {
					// hanging tip - have to test if mouse position is not over the
					// active hover and not over a tooltip set to let the user
					// interact with it.
					// for keyboard navigation: this only counts if the element does
					// not have focus.
					// for tooltips opened via the api: we need to check if it has
					// the forcedOpen flag.
					if (!isMouseOver(session.activeHover) && !session.activeHover.is(':focus') && !session.activeHover.data(DATA_FORCEDOPEN)) {
						if (tipElement.data(DATA_MOUSEONTOTIP)) {
							if (!isMouseOver(tipElement)) {
								isDesynced = true;
							}
						} else {
							isDesynced = true;
						}
					}
				}

				if (isDesynced) {
					// close the desynced tip
					hideTip(session.activeHover);
				}
			}
		}

		// expose methods
		this.showTip = beginShowTip;
		this.hideTip = hideTip;
		this.resetPosition = positionTipOnElement;
	}

	/**
	 * Determine whether a jQuery object is an SVG element
	 * @private
	 * @param {jQuery} element The element to check
	 * @return {boolean} Whether this is an SVG element
	 */
	function isSvgElement(element) {
		return window.SVGElement && element[0] instanceof SVGElement;
	}

	/**
	 * Initializes the viewport dimension cache and hooks up the mouse position
	 * tracking and viewport dimension tracking events.
	 * Prevents attaching the events more than once.
	 * @private
	 */
	function initTracking() {
		if (!session.mouseTrackingActive) {
			session.mouseTrackingActive = true;

			// grab the current viewport dimensions on load
			$(function getViewportDimensions() {
				session.scrollLeft = $window.scrollLeft();
				session.scrollTop = $window.scrollTop();
				session.windowWidth = $window.width();
				session.windowHeight = $window.height();
			});

			// hook mouse move tracking
			$document.on('mousemove', trackMouse);

			// hook viewport dimensions tracking
			$window.on({
				resize: function trackResize() {
					session.windowWidth = $window.width();
					session.windowHeight = $window.height();
				},
				scroll: function trackScroll() {
					var x = $window.scrollLeft(),
						y = $window.scrollTop();
					if (x !== session.scrollLeft) {
						session.currentX += x - session.scrollLeft;
						session.scrollLeft = x;
					}
					if (y !== session.scrollTop) {
						session.currentY += y - session.scrollTop;
						session.scrollTop = y;
					}
				}
			});
		}
	}

	/**
	 * Saves the current mouse coordinates to the session object.
	 * @private
	 * @param {jQuery.Event} event The mousemove event for the document.
	 */
	function trackMouse(event) {
		session.currentX = event.pageX;
		session.currentY = event.pageY;
	}

	/**
	 * Tests if the mouse is currently over the specified element.
	 * @private
	 * @param {jQuery} element The element to check for hover.
	 * @return {boolean}
	 */
	function isMouseOver(element) {
		// use getBoundingClientRect() because jQuery's width() and height()
		// methods do not work with SVG elements
		// compute width/height because those properties do not exist on the object
		// returned by getBoundingClientRect() in older versions of IE
		var elementPosition = element.offset(),
			elementBox = element[0].getBoundingClientRect(),
			elementWidth = elementBox.right - elementBox.left,
			elementHeight = elementBox.bottom - elementBox.top;

		return session.currentX >= elementPosition.left &&
			session.currentX <= elementPosition.left + elementWidth &&
			session.currentY >= elementPosition.top &&
			session.currentY <= elementPosition.top + elementHeight;
	}

	/**
	 * Fetches the tooltip content from the specified element's data attributes.
	 * @private
	 * @param {jQuery} element The element to get the tooltip content for.
	 * @return {(string|jQuery|undefined)} The text/HTML string, jQuery object, or
	 *     undefined if there was no tooltip content for the element.
	 */
	function getTooltipContent(element) {
		var tipText = element.data(DATA_POWERTIP),
			tipObject = element.data(DATA_POWERTIPJQ),
			tipTarget = element.data(DATA_POWERTIPTARGET),
			targetElement,
			content;

		if (tipText) {
			if ($.isFunction(tipText)) {
				tipText = tipText.call(element[0]);
			}
			content = tipText;
		} else if (tipObject) {
			if ($.isFunction(tipObject)) {
				tipObject = tipObject.call(element[0]);
			}
			if (tipObject.length > 0) {
				content = tipObject.clone(true, true);
			}
		} else if (tipTarget) {
			targetElement = $('#' + tipTarget);
			if (targetElement.length > 0) {
				content = targetElement.html();
			}
		}

		return content;
	}

	/**
	 * Finds any viewport collisions that an element (the tooltip) would have if it
	 * were absolutely positioned at the specified coordinates.
	 * @private
	 * @param {CSSCoordinates} coords Coordinates for the element.
	 * @param {number} elementWidth Width of the element in pixels.
	 * @param {number} elementHeight Height of the element in pixels.
	 * @return {number} Value with the collision flags.
	 */
	function getViewportCollisions(coords, elementWidth, elementHeight) {
		var viewportTop = session.scrollTop,
			viewportLeft =  session.scrollLeft,
			viewportBottom = viewportTop + session.windowHeight,
			viewportRight = viewportLeft + session.windowWidth,
			collisions = Collision.none;

		if (coords.top < viewportTop || Math.abs(coords.bottom - session.windowHeight) - elementHeight < viewportTop) {
			collisions |= Collision.top;
		}
		if (coords.top + elementHeight > viewportBottom || Math.abs(coords.bottom - session.windowHeight) > viewportBottom) {
			collisions |= Collision.bottom;
		}
		if (coords.left < viewportLeft || coords.right + elementWidth > viewportRight) {
			collisions |= Collision.left;
		}
		if (coords.left + elementWidth > viewportRight || coords.right < viewportLeft) {
			collisions |= Collision.right;
		}

		return collisions;
	}

	/**
	 * Counts the number of bits set on a flags value.
	 * @param {number} value The flags value.
	 * @return {number} The number of bits that have been set.
	 */
	function countFlags(value) {
		var count = 0;
		while (value) {
			value &= value - 1;
			count++;
		}
		return count;
	}

}));