Save users' last used tab, go back to it when page reloads

This also adds general cookie read/write support which I may
use in other parts of the app (e.g. saving data that is entered
in the fields for levels/exp/gems/whatever)

web_app/js/external/jquery.cookie.js

@@ -0,0 +1,117 @@
+/*!
+ * jQuery Cookie Plugin v1.4.1
+ * https://github.com/carhartl/jquery-cookie
+ *
+ * Copyright 2013 Klaus Hartl
+ * Released under the MIT license
+ */
+(function (factory) {
+	if (typeof define === 'function' && define.amd) {
+		// AMD
+		define(['jquery'], factory);
+	} else if (typeof exports === 'object') {
+		// CommonJS
+		factory(require('jquery'));
+	} else {
+		// Browser globals
+		factory(jQuery);
+	}
+}(function ($) {
+
+	var pluses = /\+/g;
+
+	function encode(s) {
+		return config.raw ? s : encodeURIComponent(s);
+	}
+
+	function decode(s) {
+		return config.raw ? s : decodeURIComponent(s);
+	}
+
+	function stringifyCookieValue(value) {
+		return encode(config.json ? JSON.stringify(value) : String(value));
+	}
+
+	function parseCookieValue(s) {
+		if (s.indexOf('"') === 0) {
+			// This is a quoted cookie as according to RFC2068, unescape...
+			s = s.slice(1, -1).replace(/\\"/g, '"').replace(/\\\\/g, '\\');
+		}
+
+		try {
+			// Replace server-side written pluses with spaces.
+			// If we can't decode the cookie, ignore it, it's unusable.
+			// If we can't parse the cookie, ignore it, it's unusable.
+			s = decodeURIComponent(s.replace(pluses, ' '));
+			return config.json ? JSON.parse(s) : s;
+		} catch(e) {}
+	}
+
+	function read(s, converter) {
+		var value = config.raw ? s : parseCookieValue(s);
+		return $.isFunction(converter) ? converter(value) : value;
+	}
+
+	var config = $.cookie = function (key, value, options) {
+
+		// Write
+
+		if (value !== undefined && !$.isFunction(value)) {
+			options = $.extend({}, config.defaults, options);
+
+			if (typeof options.expires === 'number') {
+				var days = options.expires, t = options.expires = new Date();
+				t.setTime(+t + days * 864e+5);
+			}
+
+			return (document.cookie = [
+				encode(key), '=', stringifyCookieValue(value),
+				options.expires ? '; expires=' + options.expires.toUTCString() : '', // use expires attribute, max-age is not supported by IE
+				options.path    ? '; path=' + options.path : '',
+				options.domain  ? '; domain=' + options.domain : '',
+				options.secure  ? '; secure' : ''
+			].join(''));
+		}
+
+		// Read
+
+		var result = key ? undefined : {};
+
+		// To prevent the for loop in the first place assign an empty array
+		// in case there are no cookies at all. Also prevents odd result when
+		// calling $.cookie().
+		var cookies = document.cookie ? document.cookie.split('; ') : [];
+
+		for (var i = 0, l = cookies.length; i < l; i++) {
+			var parts = cookies[i].split('=');
+			var name = decode(parts.shift());
+			var cookie = parts.join('=');
+
+			if (key && key === name) {
+				// If second argument (value) is a function it's a converter...
+				result = read(cookie, value);
+				break;
+			}
+
+			// Prevent storing a cookie that we couldn't decode.
+			if (!key && (cookie = read(cookie)) !== undefined) {
+				result[name] = cookie;
+			}
+		}
+
+		return result;
+	};
+
+	config.defaults = {};
+
+	$.removeCookie = function (key, options) {
+		if ($.cookie(key) === undefined) {
+			return false;
+		}
+
+		// Must not alter options, thus extending a fresh object...
+		$.cookie(key, '', $.extend({}, options, { expires: -1 }));
+		return !$.cookie(key);
+	};
+
+}));

web_app/js/sif_tools.js

@@ -63,9 +63,13 @@ $(document).ready(function(){
 function setup_ui_elements()
 {
 	LOG(1, "setup_ui_elements()");
+    var default_tab = $.cookie("default_tab");
+    if (isNaN(default_tab)) {
+        default_tab = 0;
+    }
 
 	$( "#tabs" ).tabs({
-		active: 0,
+		active: default_tab,
 		create: function(event, ui) {
 			var theTab = ui.tab.index();
 			LOG(3, "INIT tab created " + theTab);
@@ -208,21 +212,25 @@ function set_up_tab(tab)
 function rank_calc_tab_selected()
 {
     LOG(1, "rank_calc_tab_selected");
+    $.cookie("default_tab", 0);
 }
 
 function love_gem_calc_tab_selected()
 {
 	LOG(1, "love_gem_calc_tab_selected");
+    $.cookie("default_tab", 1);
 }
 
 function card_level_calc_tab_selected()
 {
 	LOG(1, "card_level_calc_tab_selected");
+    $.cookie("default_tab", 2);
 }
 
 function event_end_calc_tab_selected()
 {
 	LOG(1, "event_end_calc_tab_selected");
+    $.cookie("default_tab", 3);
 }
 
 function calculate_rank()

web_app/sif_tools.html

@@ -12,6 +12,7 @@
   <link href="css/external/jquery.keypad.css" rel="stylesheet">
   <link href="css/sif_tools.css" rel="stylesheet">
   <script src="js/external/jquery.js"></script>
+  <script src="js/external/jquery.cookie.js"></script>
   <script src="js/external/jquery.plugin.js"></script> 
   <script src="js/external/jquery.keypad.js"></script>
   <script src="js/external/jquery-ui.js"></script>