|
|
"""SelectionWidget classes.
|
|
|
|
|
|
Represents an enumeration 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
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
from collections import OrderedDict
|
|
|
from threading import Lock
|
|
|
|
|
|
from .widget import DOMWidget
|
|
|
from IPython.utils.traitlets import Unicode, List, Bool, Any, Dict, TraitError
|
|
|
from IPython.utils.py3compat import unicode_type
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# SelectionWidget
|
|
|
#-----------------------------------------------------------------------------
|
|
|
class _SelectionWidget(DOMWidget):
|
|
|
"""Base class for Selection widgets
|
|
|
|
|
|
``values`` can be specified as a list or dict. If given as a list,
|
|
|
it will be transformed to a dict of the form ``{str(value):value}``.
|
|
|
"""
|
|
|
|
|
|
value = Any(help="Selected value")
|
|
|
values = Dict(help="""Dictionary of {name: value} the user can select.
|
|
|
|
|
|
The keys of this dictionary are the strings that will be displayed in the UI,
|
|
|
representing the actual Python choices.
|
|
|
|
|
|
The keys of this dictionary are also available as value_names.
|
|
|
""")
|
|
|
value_name = Unicode(help="The name of the selected value", sync=True)
|
|
|
value_names = List(Unicode, help="""Read-only list of names for each value.
|
|
|
|
|
|
If values is specified as a list, this is the string representation of each element.
|
|
|
Otherwise, it is the keys of the values dictionary.
|
|
|
|
|
|
These strings are used to display the choices in the front-end.""", sync=True)
|
|
|
disabled = Bool(False, help="Enable or disable user changes", sync=True)
|
|
|
description = Unicode(help="Description of the value this widget represents", sync=True)
|
|
|
|
|
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
|
self.value_lock = Lock()
|
|
|
self._in_values_changed = False
|
|
|
if 'values' in kwargs:
|
|
|
values = kwargs['values']
|
|
|
# convert list values to an dict of {str(v):v}
|
|
|
if isinstance(values, list):
|
|
|
# preserve list order with an OrderedDict
|
|
|
kwargs['values'] = OrderedDict((unicode_type(v), v) for v in values)
|
|
|
# python3.3 turned on hash randomization by default - this means that sometimes, randomly
|
|
|
# we try to set value before setting values, due to dictionary ordering. To fix this, force
|
|
|
# the setting of self.values right now, before anything else runs
|
|
|
self.values = kwargs.pop('values')
|
|
|
DOMWidget.__init__(self, *args, **kwargs)
|
|
|
|
|
|
def _values_changed(self, name, old, new):
|
|
|
"""Handles when the values dict has been changed.
|
|
|
|
|
|
Setting values implies setting value names from the keys of the dict.
|
|
|
"""
|
|
|
self._in_values_changed = True
|
|
|
try:
|
|
|
self.value_names = list(new.keys())
|
|
|
finally:
|
|
|
self._in_values_changed = False
|
|
|
|
|
|
# ensure that the chosen value is one of the choices
|
|
|
if self.value not in new.values():
|
|
|
self.value = next(iter(new.values()))
|
|
|
|
|
|
def _value_names_changed(self, name, old, new):
|
|
|
if not self._in_values_changed:
|
|
|
raise TraitError("value_names is a read-only proxy to values.keys(). Use the values dict instead.")
|
|
|
|
|
|
def _value_changed(self, name, old, new):
|
|
|
"""Called when value has been changed"""
|
|
|
if self.value_lock.acquire(False):
|
|
|
try:
|
|
|
# Reverse dictionary lookup for the value name
|
|
|
for k,v in self.values.items():
|
|
|
if new == v:
|
|
|
# set the selected value name
|
|
|
self.value_name = k
|
|
|
return
|
|
|
# undo the change, and raise KeyError
|
|
|
self.value = old
|
|
|
raise KeyError(new)
|
|
|
finally:
|
|
|
self.value_lock.release()
|
|
|
|
|
|
def _value_name_changed(self, name, old, new):
|
|
|
"""Called when the value name has been changed (typically by the frontend)."""
|
|
|
if self.value_lock.acquire(False):
|
|
|
try:
|
|
|
self.value = self.values[new]
|
|
|
finally:
|
|
|
self.value_lock.release()
|
|
|
|
|
|
|
|
|
class ToggleButtonsWidget(_SelectionWidget):
|
|
|
_view_name = Unicode('ToggleButtonsView', sync=True)
|
|
|
|
|
|
|
|
|
class DropdownWidget(_SelectionWidget):
|
|
|
_view_name = Unicode('DropdownView', sync=True)
|
|
|
|
|
|
|
|
|
class RadioButtonsWidget(_SelectionWidget):
|
|
|
_view_name = Unicode('RadioButtonsView', sync=True)
|
|
|
|
|
|
|
|
|
class SelectWidget(_SelectionWidget):
|
|
|
_view_name = Unicode('SelectView', sync=True)
|
|
|
|
