This addresses issue #159

While working on #160, I realized that the way that sponsors were chosen was
sub-optimal.  The issues is discussed in issue #159 and this commit addresses
those issues.

This closes #159.

Author: mtiller

text/source/_themes/xogeny-semantic/static/logo-animation.js

@@ -1,37 +1,45 @@
 $(document).ready(function() {
+    // These are the sponsors
     var groups = ["CyDesign", "Wolfram", "Modelon", "Maplesoft", "DS",
 		  "Ricardo", "ITI", "GlobalCrown", "Siemens",
 		  "ST", "OSMC", "dofware", "BauschGall", "TUHH", "Schlegel"];
+
+    // This is the order we will show them in (for this page load)
+    var order = _.shuffle(groups);
+
+    // This is the current one being shown
+    var current = 0;
+
+    // This terminates animation if someone clicks on a thumbnail
     var stopAnimation = false;
 
+    // This "shows" the sponsor identified by the given id
     var showSponsor = function(id) {
 	$(".sentry").hide();
 	$(".thumbnail").removeClass("thumbshadow");
 	$("#sentry-"+id).show();
 	$("#thumbnail-"+id).addClass("thumbshadow");
     };
 
-    var pickRandom = function() {
-	console.log("pickRandom called");
+    // This shows the current sponsor (and then sets the next sponsor to be current)
+    var showCurrent = function() {
 	if (stopAnimation) return;
-	console.log("Picking a random sponsor");
-	var id = groups[Math.floor(Math.random()*groups.length)];
-	console.log("Sponsor: "+id);
-	showSponsor(id);
-	setTimeout(pickRandom, 5000);
+	showSponsor(order[current]);
+	current = (current + 1) % order.length;
+	setTimeout(showCurrent, 5000);
     }
 
+    // This sets an on-click callback on various thumbnails
     for(var i=0;i<groups.length;i++) {
 	(function() {
 	    var j = i;
 	    $("#thumbnail-"+groups[j]).click(function () {
 		stopAnimation = true;
-		console.log("Show "+groups[j]);
 		showSponsor(groups[j]);
 	    });
 	})();
     }
 
     $(".sentry").hide();
-    pickRandom();
+    showCurrent();
 });