adding a tooltip in IPython buttons

IPython/html/static/widgets/js/widget_button.js

@@ -1,70 +1,71 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     "widgets/js/widget",
     "jquery",
     "bootstrap",
 ], function(widget, $){
 
     var ButtonView = widget.DOMWidgetView.extend({
         render : function(){
             // Called when view is rendered.
             this.setElement($("<button />")
                 .addClass('btn btn-default'));
-
+            this.$el.attr("data-toggle", "tooltip");
             this.model.on('change:button_style', function(model, value) {
                 this.update_button_style();
             }, this);
             this.update_button_style('');
 
             this.update(); // Set defaults.
         },
         
         update : function(){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             var description = this.model.get('description');
+            this.$el.attr("title", this.model.get("tooltip"));
             if (description.length === 0) {
                 this.$el.html("&nbsp;"); // Preserve button height
             } else {
                 this.$el.text(description);
             }
             
             if (this.model.get('disabled')) {
                 this.$el.attr('disabled','disabled');
             } else {
                 this.$el.removeAttr('disabled');
             }
 
             return ButtonView.__super__.update.apply(this);
         },
 
         update_button_style: function(previous_trait_value) {
             var class_map = {
                 primary: ['btn-primary'],
                 success: ['btn-success'],
                 info: ['btn-info'],
                 warning: ['btn-warning'],
                 danger: ['btn-danger']
             };
             this.update_mapped_classes(class_map, 'button_style', previous_trait_value);
         },
 
         events: {
             // Dictionary of events and their handlers.
             'click': '_handle_click',
         },
         
         _handle_click: function(){
             // Handles when the button is clicked.
             this.send({event: 'click'});
         },
     });
 
     return {
         'ButtonView': ButtonView,
     };
 });

IPython/html/widgets/widget_button.py

@@ -1,70 +1,71 b''
 """Button class.  
 
 Represents a button in the frontend using a widget.  Allows user to listen for
 click events on the button and trigger backend code when the clicks are fired.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import DOMWidget, CallbackDispatcher
 from IPython.utils.traitlets import Unicode, Bool, CaselessStrEnum
 from IPython.utils.warn import DeprecatedClass
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class Button(DOMWidget):
     """Button widget.
 
     This widget has an `on_click` method that allows you to listen for the 
     user clicking on the button.  The click event itself is stateless."""
     _view_name = Unicode('ButtonView', sync=True)
 
     # Keys
-    description = Unicode('', help="Description of the button (label).", sync=True)
+    description = Unicode('', help="Button label.", sync=True)
+    tooltip = Unicode(help="Tooltip caption of the button.", sync=True)
     disabled = Bool(False, help="Enable or disable user changes.", sync=True)
 
     button_style = CaselessStrEnum(
         values=['primary', 'success', 'info', 'warning', 'danger', ''], 
         default_value='', allow_none=True, sync=True, help="""Use a
         predefined styling for the button.""")
     
     def __init__(self, **kwargs):
         """Constructor"""
         super(Button, self).__init__(**kwargs)
         self._click_handlers = CallbackDispatcher()
         self.on_msg(self._handle_button_msg)
 
     def on_click(self, callback, remove=False):
         """Register a callback to execute when the button is clicked.
 
         The callback will be called with one argument,
         the clicked button widget instance.
 
         Parameters
         ----------
         remove : bool (optional)
             Set to true to remove the callback from the list of callbacks."""
         self._click_handlers.register_callback(callback, remove=remove)
 
     def _handle_button_msg(self, _, content):
         """Handle a msg from the front-end.
 
         Parameters
         ----------
         content: dict
             Content of the msg."""
         if content.get('event', '') == 'click':
             self._click_handlers(self)
 
 
 # Remove in IPython 4.0
 ButtonWidget = DeprecatedClass(Button, 'ButtonWidget')