Fix command mode & popup view bug

Added elements property to PopupView

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

@@ -93,8 +93,14 b''
         WidgetManager.prototype._handle_display_view = function (view) {
             // Have the IPython keyboard manager disable its event
             // handling so the widget can capture keyboard input.
-            // Note, this is only done on the outer most widget.
-            IPython.keyboard_manager.register_events(view.$el);
+            // Note, this is only done on the outer most widgets.
+            if (view.elements) {
+                for (var i = 0; i < view.elements.length; i++) {
+                    IPython.keyboard_manager.register_events(view.elements[i]);
+                }
+            } else {
+                IPython.keyboard_manager.register_events(view.$el);
+            }
         };
 
         WidgetManager.prototype.create_view = function(model, options, view) {

IPython/html/static/notebook/js/widgets/widget_container.js

@@ -75,6 +75,14 b' define(["notebook/js/widgets/widget"], function(WidgetManager) {'
                 .mousedown(function(){
                     that.bring_to_front();
                 });
+
+            // Set the elements array since the this.$window element is not child
+            // of this.$el and the parent widget manager or other widgets may
+            // need to know about all of the top-level widgets.  The IPython
+            // widget manager uses this to register the elements with the
+            // keyboard manager.
+            this.elements = [this.$el, this.$window]
+
             this.$title_bar = $('<div />')
                 .addClass('popover-title')
                 .appendTo(this.$window)