notebook/IPython/html/widgets/widget_string.py
Jonathan Frederic 4f663d896d Made scroll to bottom use msgs
allow multiple msg handlers
added send to view to automatically hookup callbacks
changed send signature to optionally accept a cell to connect callbacks
2014-01-16 10:57:04 +00:00

112 lines
3.9 KiB
Python

"""StringWidget class.
Represents a unicode string using a widget.
"""
#-----------------------------------------------------------------------------
# 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, List, Int
#-----------------------------------------------------------------------------
# Classes
#-----------------------------------------------------------------------------
class StringWidget(Widget):
target_name = Unicode('StringWidgetModel')
default_view_name = Unicode('TextBoxView')
# Keys
_keys = ['value', 'disabled', 'description']
value = Unicode(help="String value")
disabled = Bool(False, help="Enable or disable user changes")
description = Unicode(help="Description of the value this widget represents")
def __init__(self, **kwargs):
super(StringWidget, self).__init__(**kwargs)
self._submission_callbacks = []
self.on_msg(self._handle_string_msg)
def scroll_to_bottom(self):
self._comm.send({"method": "scroll_to_bottom"})
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)
elif not callback in self._click_handlers:
self._click_handlers.append(callback)
def _handle_string_msg(self, content):
"""Handle a msg from the front-end
Parameters
----------
content: dict
Content of the msg."""
if 'event' in content and content['event'] == 'submit':
self._handle_submit()
def on_submit(self, callback, remove=False):
"""Register a callback to handle text submission (triggered when the
user clicks enter).
Parameters
callback: Method handle
Function to be called when the text has been submitted. Function
can have two possible signatures:
callback()
callback(sender)
remove: bool (optional)
Whether or not to unregister the callback"""
if remove and callback in self._submission_callbacks:
self._submission_callbacks.remove(callback)
elif not remove and not callback in self._submission_callbacks:
self._submission_callbacks.append(callback)
def _handle_submit(self):
"""Handles when a string widget view is submitted."""
for handler in self._submission_callbacks:
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('StringWidget submit callback must ' \
'accept 0 or 1 arguments.')