Add base from clarity theme from @Nijikokun

theme/javascript/core/progress.js

@@ -10,15 +10,16 @@ define([
     };
 
     // Return all levels
-    var getLevels = function() {
+    var getLevels = function () {
         var levels = $(".book-summary li[data-level]");
+
         return _.map(levels, function(level) {
             return $(level).data("level").toString();
         });
     };
 
     // Return a map chapter -> number (timestamp)
-    var getProgress = function() {
+    var getProgress = function () {
         // Current level
         var progress = storage.get("progress", {});
 
@@ -33,27 +34,33 @@ define([
     };
 
     // Change value of progress for a level
-    var markProgress = function(level, state) {
-        if (state == null) state = true;
-
+    var markProgress = function (level, state) {
         var progress = getProgress();
-        progress[level] = state? Date.now() : 0;
+
+        if (state == null) {
+            state = true;
+        }
+
+        progress[level] = state
+            ? Date.now()
+            : 0;
 
         storage.set("progress", progress);
     };
 
     // Show progress
-    var showProgress = function() {        
-        // Update progress
+    var showProgress = function () {
         var progress = getProgress();
         var $summary = $(".book-summary");
 
-        _.each(progress, function(value, level) {
+        _.each(progress, function (value, level) {
             $summary.find("li[data-level='"+level+"']").toggleClass("done", value > 0);
         });
 
-        // Mark current progress
-        markProgress(getCurrentLevel(), true);
+        // Mark current progress if we have not already
+        if (!progress[getCurrentLevel()]) {
+            markProgress(getCurrentLevel(), true);
+        }
     };
 
     return {