restore checkpoints in a sub-list

minor styling update to the restore dialog as well

IPython/frontend/html/notebook/static/css/style.min.css

@@ -943,6 +943,7 b' a.heading-anchor:link,a.heading-anchor:visited{text-decoration:none;color:inheri'
 div.raw_input{padding-top:0px;padding-bottom:0px;height:1em;line-height:1em;font-family:monospace;}
 span.input_prompt{font-family:inherit;}
 input.raw_input{font-family:inherit;font-size:inherit;color:inherit;width:auto;margin:-2px 0px 0px 1px;padding-left:1px;padding-top:2px;height:1em;}
+p.p-space{margin-bottom:10px;}
 .rendered_html{color:black;}.rendered_html em{font-style:italic;}
 .rendered_html strong{font-weight:bold;}
 .rendered_html u{text-decoration:underline;}

IPython/frontend/html/notebook/static/js/menubar.js

@@ -60,6 +60,7 b' var IPython = (function (IPython) {'
                 IPython.notebook.select(i);
             }
         });
+        this.element.find("#restore_checkpoint").find("ul").find("li").hide();
     };
 
 
@@ -228,26 +229,33 b' var IPython = (function (IPython) {'
         });
         
         $([IPython.events]).on('checkpoint_created.Notebook', function (event, data) {
-            that.update_restore_checkpoint(data);
+            that.update_restore_checkpoint([data]);
         });
     };
 
-    MenuBar.prototype.update_restore_checkpoint = function(checkpoint) {
-        if (!checkpoint) {
-            this.element.find("#restore_checkpoint")
-                .addClass('ui-state-disabled')
-                .off('click')
-                .find('a').text("Revert");
-            return;
+    MenuBar.prototype.update_restore_checkpoint = function(checkpoints) {
+        if (! checkpoints) {
+            checkpoints = [];
         };
-        var d = new Date(checkpoint.last_modified);
-        this.element.find("#restore_checkpoint")
-            .removeClass('ui-state-disabled')
-            .off('click')
-            .click(function () {
-                IPython.notebook.restore_checkpoint_dialog();
-            }).find('a').html("Revert to: <br/>" + d.format("mmm dd HH:MM:ss"));
-    }
+        this.element.find("#restore_checkpoint").find("ul").find("li").each(function(i) {
+            var li = $(this);
+            var a = li.find("a");
+            a.off("click");
+            if (checkpoints.length <= i) {
+                li.hide();
+                return;
+            } else {
+                li.show();
+            };
+            var checkpoint = checkpoints[i];
+            var d = new Date(checkpoint.last_modified);
+            li.find('a').text(
+                d.format("mmm dd HH:MM:ss")
+            ).click(function () {
+                IPython.notebook.restore_checkpoint_dialog(checkpoint);
+            });
+        });
+    };
 
     IPython.MenuBar = MenuBar;
 

IPython/frontend/html/notebook/static/js/notebook.js

@@ -1839,7 +1839,7 b' var IPython = (function (IPython) {'
         } else {
             this.last_checkpoint = null;
         }
-        $([IPython.events]).trigger('checkpoints_listed.Notebook', data);
+        $([IPython.events]).trigger('checkpoints_listed.Notebook', [data]);
     };
 
     /**
@@ -1894,15 +1894,16 b' var IPython = (function (IPython) {'
         $([IPython.events]).trigger('checkpoint_failed.Notebook');
     };
     
-    Notebook.prototype.restore_checkpoint_dialog = function () {
+    Notebook.prototype.restore_checkpoint_dialog = function (checkpoint) {
         var that = this;
-        var checkpoint = this.last_checkpoint;
+        var checkpoint = checkpoint || this.last_checkpoint;
         if ( ! checkpoint ) {
             console.log("restore dialog, but no checkpoint to restore to!");
             return;
         }
         var dialog = $('<div/>').append(
-            $('<p/>').text("Are you sure you want to revert the notebook to " +
+            $('<p/>').addClass("p-space").text(
+                "Are you sure you want to revert the notebook to " +
                 "the latest checkpoint?"
             ).append(
                 $("<strong/>").text(
@@ -1910,9 +1911,11 b' var IPython = (function (IPython) {'
                 )
             )
         ).append(
-            $('<p/>').text("The checkpoint was last updated at")
+            $('<p/>').addClass("p-space").text("The checkpoint was last updated at:")
         ).append(
-            $('<p/>').text(Date(checkpoint.last_modified))
+            $('<p/>').addClass("p-space").text(
+                Date(checkpoint.last_modified)
+            ).css("text-align", "center")
         );
         
         $(document).append(dialog);

IPython/frontend/html/notebook/static/js/savewidget.js

@@ -57,7 +57,7 b' var IPython = (function (IPython) {'
             that.set_save_status('Last Save Failed!');
         });
         $([IPython.events]).on('checkpoints_listed.Notebook', function (event, data) {
-            that.set_last_checkpoint(data);
+            that.set_last_checkpoint(data[0]);
         });
         
         $([IPython.events]).on('checkpoint_created.Notebook', function (event, data) {

IPython/frontend/html/notebook/static/less/notebook.less

@@ -507,3 +507,7 b' input.raw_input {'
   height: 1em;
 }
 
+p.p-space {
+  margin-bottom: 10px;
+}
+

IPython/frontend/html/notebook/templates/notebook.html

@@ -59,7 +59,15 b' class="notebook_app"'
                 <li id="rename_notebook"><a href="#">Rename...</a></li>
                 <li id="save_checkpoint"><a href="#">Save and Checkpoint</a></li>
                 <hr/>
-                <li id="restore_checkpoint"><a href="#">Revert to Checkpoint</a></li>
+                <li id="restore_checkpoint"><a href="#">Revert to Checkpoint</a>
+                  <ul>
+                    <li><a href="#"></a></li>
+                    <li><a href="#"></a></li>
+                    <li><a href="#"></a></li>
+                    <li><a href="#"></a></li>
+                    <li><a href="#"></a></li>
+                  </ul>
+                </li>
                 <hr/>
                 <li><a href="#">Download as</a>
                     <ul>