function Photonic_Lightbox() {
		this.socialIcons = "<div id='photonic-social'>" +
			"<a class='photonic-share-fb' href='https://www.facebook.com/sharer/sharer.php?u={photonic_share_link}&amp;title={photonic_share_title}&amp;picture={photonic_share_image}' target='_blank' title='Share on Facebook'><div class='icon-facebook'></div></a>" +
			"<a class='photonic-share-twitter' href='https://twitter.com/share?url={photonic_share_link}&amp;text={photonic_share_title}' target='_blank' title='Share on Twitter'><div class='icon-twitter'></div></a>" +
			"<a class='photonic-share-pinterest' data-pin-do='buttonPin' href='https://www.pinterest.com/pin/create/button/?url={photonic_share_link}&media={photonic_share_image}&description={photonic_share_title}' data-pin-custom='true' target='_blank' title='Share on Pinterest'><div class='icon-pinterest'></div></a>" +
			"</div>";
		var lastDeep;
		this.videoIndex = 1;
	}

	Photonic_Lightbox.prototype.getVideoSize = function(url, baseline){
		return new Promise(function(resolve){
			// create the video element
			var video = document.createElement('video');

			// place a listener on it
			video.addEventListener( "loadedmetadata", function () {
				// retrieve dimensions
				var height = this.videoHeight;
				var width = this.videoWidth;

				var videoAspectRatio = this.videoWidth / this.videoHeight;
				var baseAspectRatio = baseline.width / baseline.height;

				var newWidth, newHeight;
				if (baseAspectRatio > videoAspectRatio) {
					// Window is wider than it needs to be ... constrain by window height
					newHeight = baseline.height;
					newWidth = width * newHeight / height;
				}
				else {
					// Window is narrower than it needs to be ... constrain by window width
					newWidth = baseline.width;
					newHeight = height * newWidth / width;
				}

				// send back result
				resolve({
					height : height,
					width : width,
					newHeight: newHeight,
					newWidth: newWidth
				});
			}, false );

			// start download meta-datas
			video.src = url;
		});
	};

	Photonic_Lightbox.prototype.getImageSize = function(url, baseline){
		return new Promise(function(resolve){
			var image = document.createElement('img');

			// place a listener on it
			image.addEventListener( "load", function () {
				// retrieve dimensions
				var height = this.height;
				var width = this.width;

				var imageAspectRatio = this.width / this.height;
				var baseAspectRatio = baseline.width / baseline.height;

				var newWidth, newHeight;
				if (baseAspectRatio > imageAspectRatio) {
					// Window is wider than it needs to be ... constrain by window height
					newHeight = baseline.height;
					newWidth = width * newHeight / height;
				}
				else {
					// Window is narrower than it needs to be ... constrain by window width
					newWidth = baseline.width;
					newHeight = height * newWidth / width;
				}

				// send back result
				resolve({
					height : height,
					width : width,
					newHeight: newHeight,
					newWidth: newWidth
				});
			}, false );

			// start download meta-datas
			image.src = url;
		});
	};

	Photonic_Lightbox.prototype.addSocial = function(selector, shareable) {
		if ((Photonic_JS.social_media === undefined || Photonic_JS.social_media === '') && shareable['buy'] === undefined) {
			return;
		}
		var socialEl = document.getElementById('photonic-social');
		if (socialEl !== null) {
			socialEl.parentNode.removeChild(socialEl);
		}

		if (location.hash !== '') {
			var social = this.socialIcons.replace(/{photonic_share_link}/g, encodeURIComponent(shareable['url'])).
			replace(/{photonic_share_title}/g, encodeURIComponent(shareable['title'])).
			replace(/{photonic_share_image}/g, encodeURIComponent(shareable['image']));

			var selectorEl;
			if (typeof selector === 'string') {
				selectorEl = document.documentElement.querySelector(selector);
				if (selectorEl !== null) {
					selectorEl.insertAdjacentHTML('beforeend', social);
				}
			}

			if (Photonic_JS.social_media === undefined || Photonic_JS.social_media === '') {

				var socialMediaIcons = document.documentElement.querySelectorAll('.photonic-share-fb, .photonic-share-twitter, .photonic-share-pinterest');
				Array.prototype.forEach.call(socialMediaIcons, function(socialIcon) {
					socialIcon.parentNode.removeChild(socialIcon);
				});
			}

			if (!supportsSVG) {
				var icon = $('#photonic-social div');
				var bg = icon.css('background-image');
				bg = bg.replace( 'svg', 'png' );
				icon.css({'background-image': bg});
			}
		}
	};

	Photonic_Lightbox.prototype.setHash = function(a) {
		if (Photonic_JS.deep_linking === undefined || Photonic_JS.deep_linking === 'none') {
			return;
		}

		var hash = typeof a === 'string' ? a : $(a).data('photonicDeep');
		if (hash === undefined) {
			return;
		}

		if (typeof(window.history.pushState) === 'function' && Photonic_JS.deep_linking === 'yes-history') {
			window.history.pushState({}, document.title, '#' + hash);
		}
		else if (typeof(window.history.replaceState) === 'function' && Photonic_JS.deep_linking === 'no-history') {
			window.history.replaceState({}, document.title, '#' + hash);
		}
		else {
			document.location.hash = hash;
		}
	};

	Photonic_Lightbox.prototype.unsetHash = function() {
		lastDeep = (lastDeep === undefined || deep !== '') ? location.hash : lastDeep;
		if (window.history && 'replaceState' in window.history) {
			history.replaceState({}, document.title, location.href.substr(0, location.href.length-location.hash.length));
		}
		else {
			window.location.hash = '';
		}
	};

	Photonic_Lightbox.prototype.changeHash = function() {
		var node = deep;

		if (node != null) {
			if (node.length > 1 && photonicLightbox !== null && photonicLightbox !== undefined) {
				if (window.location.hash && node.indexOf('#access_token=') !== -1) {
					photonicLightbox.unsetHash();
				}
				else {
					node = node.substr(1);
					var allMatches = document.querySelectorAll('[data-photonic-deep="' + node + '"]'); //$('[data-photonic-deep="' + node + '"]');
					if (allMatches.length > 0) {
						var thumbToClick = allMatches[0];
						$(thumbToClick).click();
						photonicLightbox.setHash(node);
					}
				}
			}
		}
	};

	Photonic_Lightbox.prototype.catchYouTubeURL = function(url) {
		var regExp = /^.*(youtu\.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]*).*/;
		var match = url.match(regExp);
		if (match && match[2].length === 11) {
			return match[2];
		}
	};

	Photonic_Lightbox.prototype.catchVimeoURL = function(url) {
		var regExp = /(?:www\.|player\.)?vimeo.com\/(?:channels\/(?:\w+\/)?|groups\/(?:[^\/]*)\/videos\/|album\/(?:\d+)\/video\/|video\/|)(\d+)(?:[a-zA-Z0-9_\-]+)?/;
		var match = url.match(regExp);
		if (match) {
			return match[1];
		}
	};

	Photonic_Lightbox.prototype.soloImages = function() {
		$('a[href]').filter(function() {
			return /(\.jpg|\.jpeg|\.bmp|\.gif|\.png)/i.test( this.getAttribute('href'));
		}).addClass("launch-gallery-" + Photonic_JS.slideshow_library).addClass(Photonic_JS.slideshow_library);
	};

	Photonic_Lightbox.prototype.changeVideoURL = function(element, regular, embed) {
		// Implemented in individual lightboxes. Empty for unsupported lightboxes
	};

	Photonic_Lightbox.prototype.hostedVideo = function(a) {
		// Implemented in individual lightboxes. Empty for unsupported lightboxes
	};

	Photonic_Lightbox.prototype.soloVideos = function() {
		var self = this;
		if (Photonic_JS.lightbox_for_videos) {
			$('a[href]').each(function() {
				var regular, embed;
				var href = this.getAttribute('href');
				var youTube = self.catchYouTubeURL(href);
				var vimeo = self.catchVimeoURL(href);
				if ((youTube) !== undefined) {
					regular = 'https://youtube.com/watch?v=' + youTube;
					embed = 'https://youtube.com/embed/' + youTube;
				}
				else if (vimeo !== undefined) {
					regular = 'https://vimeo.com/' + vimeo;
					embed = 'https://player.vimeo.com/video/' + vimeo;
				}

				if (regular !== undefined) {
					$(this).addClass(Photonic_JS.slideshow_library + "-video");
					self.changeVideoURL(this, regular, embed);
				}
				self.hostedVideo(this);
			});
		}
	};

	Photonic_Lightbox.prototype.handleSolos = function() {
		if (Photonic_JS.lightbox_for_all) {
			this.soloImages();
		}
		this.soloVideos();

		$(window).on('load', this.changeHash);
		$(window).on('hashchange', this.changeHash);
	};

	Photonic_Lightbox.prototype.initialize = function() {
		this.handleSolos();
		// Implemented by child classes
	};

	Photonic_Lightbox.prototype.initializeForNewContainer = function(containerId) {
		// Implemented by individual lightboxes. Empty for cases where not required
	};

	Photonic_Lightbox.prototype.initializeForExisting = function() {
		// Implemented by child classes
	};

	Photonic_Lightbox.prototype.initializeForSlideshow = function(selector, slider) {
		// Implemented by child classes
	};