Separated recenter and top actions.

IPython/html/static/notebook/js/actions.js

@@ -368,14 +368,24 define(function(require){
                 return env.notebook.scroll_manager.scroll(-1);
             },
         },
-        'recenter-top-bottom': {
-            help: "Move the current cell to the center, top or bottom",
+        'recenter': {
+            help: "Move the current cell to the center",
             handler: function (env, event) {
                 if(event){
                     event.preventDefault();
                 }
                 var cell = env.notebook.get_selected_index();
-                return env.notebook.scroll_to_cell(cell);
+                return env.notebook.scroll_middle_to_cell(cell, 0);
+            }
+        },
+        'top': {
+            help: "Move the current cell to the top",
+            handler: function (env, event) {
+                if(event){
+                    event.preventDefault();
+                }
+                var cell = env.notebook.get_selected_index();
+                return env.notebook.scroll_to_cell(cell, 0);
             }
         },
         'save-notebook':{

IPython/html/static/notebook/js/keyboardmanager.js

@@ -80,7 +80,8 define([
             'down'                : 'ipython.move-cursor-down-or-next-cell',
             'ctrl-shift--'        : 'ipython.split-cell-at-cursor',
             'ctrl-shift-subtract' : 'ipython.split-cell-at-cursor',
-            'ctrl-l'              : 'ipython.recenter-top-bottom'
+            'ctrl-l'              : 'ipython.recenter',
+            'ctrl-shift-l'        : 'ipython.top'
         };
     };
 

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

@@ -361,6 +361,29 define(function (require) {
     };
 
     /**
+     * Scroll the middle of the page to a given cell.
+     *
+     * @param {integer}  index - An index of the cell to view
+     * @param {integer}  time - Animation time in milliseconds
+     * @return {integer} Pixel offset from the top of the container
+     */
+    Notebook.prototype.scroll_middle_to_cell = function (index, time) {
+        var cells = this.get_cells();
+        time = time || 0;
+        index = Math.min(cells.length-1,index);
+        index = Math.max(0             ,index);
+        // var scroll_value = cells[index].element.position().top-cells[0].element.position().top ;
+        var sme = this.scroll_manager.element;
+        var h = sme.height();
+        var st = sme.scrollTop();
+        var t = sme.offset().top;
+        var ct = cells[index].element.offset().top;
+        var scroll_value =  st + ct - (t + h/2);
+        this.scroll_manager.element.animate({scrollTop:scroll_value}, time);
+        return scroll_value;
+    };
+
+    /**
      * Scroll to the bottom of the page.
      */
     Notebook.prototype.scroll_to_bottom = function () {