Set default element to be styled in built-in views

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

@@ -25,6 +25,7 @@ require(["notebook/js/widget"], function(){
                 })
                 .appendTo(this.$el);
 
+            this.$el_to_style = this.$checkbox; // Set default element to style
             this.update(); // Set defaults.
         },
         
@@ -64,6 +65,7 @@ require(["notebook/js/widget"], function(){
                 .attr('type', 'button')
                 .attr('data-toggle', 'button')
                 .appendTo(this.$el);
+            this.$el_to_style = this.$button; // Set default element to style
 
             this.update(); // Set defaults.
         },

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

@@ -18,6 +18,7 @@ require(["notebook/js/widget"], function(){
                                 .addClass('widget_item')
                                 .addClass('btn-group')
                                 .appendTo(this.$el);
+            this.$el_to_style = this.$buttongroup; // Set default element to style
             this.$droplabel = $('<button />')
                                 .addClass('btn')
                                 .addClass('widget-combo-btn')
@@ -96,6 +97,7 @@ require(["notebook/js/widget"], function(){
                 .appendTo(this.$el)
                 .addClass('widget-container')
                 .addClass('vbox');
+            this.$el_to_style = this.$container; // Set default element to style
             this.update();
         },
         
@@ -181,6 +183,7 @@ require(["notebook/js/widget"], function(){
                 .addClass('btn-group')
                 .attr('data-toggle', 'buttons-radio')
                 .appendTo(this.$el);
+            this.$el_to_style = this.$buttongroup; // Set default element to style
             this.update();
         },
         

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

@@ -36,6 +36,7 @@ require(["notebook/js/widget"], function(){
                 .attr('rows', 5)
                 .addClass('widget-text')
                 .appendTo(this.$el);
+            this.$el_to_style = this.$textbox; // Set default element to style
             this.update(); // Set defaults.
         },
         
@@ -89,6 +90,7 @@ require(["notebook/js/widget"], function(){
                 .addClass('input')
                 .addClass('widget-text')
                 .appendTo(this.$el);
+            this.$el_to_style = this.$textbox; // Set default element to style
             this.update(); // Set defaults.
         },