|
|
"""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
|
|
|
#-----------------------------------------------------------------------------
|
|
|
import inspect
|
|
|
import types
|
|
|
|
|
|
from .widget import Widget
|
|
|
from IPython.utils.traitlets import Unicode, Bool, Int
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Classes
|
|
|
#-----------------------------------------------------------------------------
|
|
|
class ButtonWidget(Widget):
|
|
|
target_name = Unicode('ButtonWidgetModel')
|
|
|
default_view_name = Unicode('ButtonView')
|
|
|
|
|
|
# Keys
|
|
|
_keys = ['clicks', 'description', 'disabled']
|
|
|
clicks = Int(0, help="Number of times the button has been clicked.")
|
|
|
description = Unicode('', help="Description of the button (label).")
|
|
|
disabled = Bool(False, help="Enable or disable user changes.")
|
|
|
|
|
|
|
|
|
def __init__(self, **kwargs):
|
|
|
self._click_handlers = []
|
|
|
super(ButtonWidget, self).__init__(**kwargs)
|
|
|
|
|
|
|
|
|
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."""
|
|
|
if remove:
|
|
|
self._click_handlers.remove(callback)
|
|
|
else:
|
|
|
self._click_handlers.append(callback)
|
|
|
|
|
|
|
|
|
def _clicks_changed(self, name, old, new):
|
|
|
"""Handles when the clicks property has been changed. Fires on_click
|
|
|
callbacks when appropriate."""
|
|
|
if new > old:
|
|
|
for handler in self._click_handlers:
|
|
|
if callable(handler):
|
|
|
argspec = inspect.getargspec(handler)
|
|
|
nargs = len(argspec[0])
|
|
|
|
|
|
# Bound methods have an additional 'self' argument
|
|
|
if isinstance(handler, types.MethodType):
|
|
|
nargs -= 1
|
|
|
|
|
|
# Call the callback
|
|
|
if nargs == 0:
|
|
|
handler()
|
|
|
elif nargs == 1:
|
|
|
handler(self)
|
|
|
else:
|
|
|
raise TypeError('ButtonWidget click callback must ' \
|
|
|
'accept 0 or 1 arguments.')
|
|
|
|
