notebook/IPython/html/widgets/widget_button.py
2014-01-22 16:21:00 -08:00

61 lines
2.4 KiB
Python

"""ButtonWidget 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
#-----------------------------------------------------------------------------
# Classes
#-----------------------------------------------------------------------------
class ButtonWidget(DOMWidget):
_view_name = Unicode('ButtonView', sync=True)
# Keys
description = Unicode('', help="Description of the button (label).", sync=True)
disabled = Bool(False, help="Enable or disable user changes.", sync=True)
def __init__(self, **kwargs):
"""Constructor"""
super(ButtonWidget, self).__init__(**kwargs)
self._click_handlers = CallbackDispatcher(acceptable_nargs=[0, 1])
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 can either accept no parameters or one sender parameter:
- callback()
- callback(sender)
If the callback has a sender parameter, the ButtonWidget instance that
called the callback will be passed into the method as the sender.
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 'event' in content and content['event'] == 'click':
self._click_handlers()
self._click_handlers(self)