/usr/lib/python3/dist-packages/IPython/html/widgets/widget.py is in ipython3-notebook 2.3.0-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 | """Base Widget class. Allows user to create widgets in the back-end that render
in the IPython notebook front-end.
"""
#-----------------------------------------------------------------------------
# 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 contextlib import contextmanager
from IPython.core.getipython import get_ipython
from IPython.kernel.comm import Comm
from IPython.config import LoggingConfigurable
from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, Tuple, Int
from IPython.utils.py3compat import string_types
#-----------------------------------------------------------------------------
# Classes
#-----------------------------------------------------------------------------
class CallbackDispatcher(LoggingConfigurable):
"""A structure for registering and running callbacks"""
callbacks = List()
def __call__(self, *args, **kwargs):
"""Call all of the registered callbacks."""
value = None
for callback in self.callbacks:
try:
local_value = callback(*args, **kwargs)
except Exception as e:
ip = get_ipython()
if ip is None:
self.log.warn("Exception in callback %s: %s", callback, e, exc_info=True)
else:
ip.showtraceback()
else:
value = local_value if local_value is not None else value
return value
def register_callback(self, callback, remove=False):
"""(Un)Register a callback
Parameters
----------
callback: method handle
Method to be registered or unregistered.
remove=False: bool
Whether to unregister the callback."""
# (Un)Register the callback.
if remove and callback in self.callbacks:
self.callbacks.remove(callback)
elif not remove and callback not in self.callbacks:
self.callbacks.append(callback)
def _show_traceback(method):
"""decorator for showing tracebacks in IPython"""
def m(self, *args, **kwargs):
try:
return(method(self, *args, **kwargs))
except Exception as e:
ip = get_ipython()
if ip is None:
self.log.warn("Exception in widget method %s: %s", method, e, exc_info=True)
else:
ip.showtraceback()
return m
class Widget(LoggingConfigurable):
#-------------------------------------------------------------------------
# Class attributes
#-------------------------------------------------------------------------
_widget_construction_callback = None
widgets = {}
@staticmethod
def on_widget_constructed(callback):
"""Registers a callback to be called when a widget is constructed.
The callback must have the following signature:
callback(widget)"""
Widget._widget_construction_callback = callback
@staticmethod
def _call_widget_constructed(widget):
"""Static method, called when a widget is constructed."""
if Widget._widget_construction_callback is not None and callable(Widget._widget_construction_callback):
Widget._widget_construction_callback(widget)
#-------------------------------------------------------------------------
# Traits
#-------------------------------------------------------------------------
_model_name = Unicode('WidgetModel', help="""Name of the backbone model
registered in the front-end to create and sync this widget with.""")
_view_name = Unicode(help="""Default view registered in the front-end
to use to represent the widget.""", sync=True)
_comm = Instance('IPython.kernel.comm.Comm')
msg_throttle = Int(3, sync=True, help="""Maximum number of msgs the
front-end can send before receiving an idle msg from the back-end.""")
keys = List()
def _keys_default(self):
return [name for name in self.traits(sync=True)]
_property_lock = Tuple((None, None))
_display_callbacks = Instance(CallbackDispatcher, ())
_msg_callbacks = Instance(CallbackDispatcher, ())
#-------------------------------------------------------------------------
# (Con/de)structor
#-------------------------------------------------------------------------
def __init__(self, **kwargs):
"""Public constructor"""
super(Widget, self).__init__(**kwargs)
self.on_trait_change(self._handle_property_changed, self.keys)
Widget._call_widget_constructed(self)
def __del__(self):
"""Object disposal"""
self.close()
#-------------------------------------------------------------------------
# Properties
#-------------------------------------------------------------------------
@property
def comm(self):
"""Gets the Comm associated with this widget.
If a Comm doesn't exist yet, a Comm will be created automagically."""
if self._comm is None:
# Create a comm.
self._comm = Comm(target_name=self._model_name)
self._comm.on_msg(self._handle_msg)
self._comm.on_close(self._close)
Widget.widgets[self.model_id] = self
# first update
self.send_state()
return self._comm
@property
def model_id(self):
"""Gets the model id of this widget.
If a Comm doesn't exist yet, a Comm will be created automagically."""
return self.comm.comm_id
#-------------------------------------------------------------------------
# Methods
#-------------------------------------------------------------------------
def _close(self):
"""Private close - cleanup objects, registry entries"""
del Widget.widgets[self.model_id]
self._comm = None
def close(self):
"""Close method.
Closes the widget which closes the underlying comm.
When the comm is closed, all of the widget views are automatically
removed from the front-end."""
if self._comm is not None:
self._comm.close()
self._close()
def send_state(self, key=None):
"""Sends the widget state, or a piece of it, to the front-end.
Parameters
----------
key : unicode (optional)
A single property's name to sync with the front-end.
"""
self._send({
"method" : "update",
"state" : self.get_state()
})
def get_state(self, key=None):
"""Gets the widget state, or a piece of it.
Parameters
----------
key : unicode (optional)
A single property's name to get.
"""
keys = self.keys if key is None else [key]
return {k: self._pack_widgets(getattr(self, k)) for k in keys}
def send(self, content):
"""Sends a custom msg to the widget model in the front-end.
Parameters
----------
content : dict
Content of the message to send.
"""
self._send({"method": "custom", "content": content})
def on_msg(self, callback, remove=False):
"""(Un)Register a custom msg receive callback.
Parameters
----------
callback: callable
callback will be passed two arguments when a message arrives::
callback(widget, content)
remove: bool
True if the callback should be unregistered."""
self._msg_callbacks.register_callback(callback, remove=remove)
def on_displayed(self, callback, remove=False):
"""(Un)Register a widget displayed callback.
Parameters
----------
callback: method handler
Must have a signature of::
callback(widget, **kwargs)
kwargs from display are passed through without modification.
remove: bool
True if the callback should be unregistered."""
self._display_callbacks.register_callback(callback, remove=remove)
#-------------------------------------------------------------------------
# Support methods
#-------------------------------------------------------------------------
@contextmanager
def _lock_property(self, key, value):
"""Lock a property-value pair.
NOTE: This, in addition to the single lock for all state changes, is
flawed. In the future we may want to look into buffering state changes
back to the front-end."""
self._property_lock = (key, value)
try:
yield
finally:
self._property_lock = (None, None)
def _should_send_property(self, key, value):
"""Check the property lock (property_lock)"""
return key != self._property_lock[0] or \
value != self._property_lock[1]
# Event handlers
@_show_traceback
def _handle_msg(self, msg):
"""Called when a msg is received from the front-end"""
data = msg['content']['data']
method = data['method']
if not method in ['backbone', 'custom']:
self.log.error('Unknown front-end to back-end widget msg with method "%s"' % method)
# Handle backbone sync methods CREATE, PATCH, and UPDATE all in one.
if method == 'backbone' and 'sync_data' in data:
sync_data = data['sync_data']
self._handle_receive_state(sync_data) # handles all methods
# Handle a custom msg from the front-end
elif method == 'custom':
if 'content' in data:
self._handle_custom_msg(data['content'])
def _handle_receive_state(self, sync_data):
"""Called when a state is received from the front-end."""
for name in self.keys:
if name in sync_data:
value = self._unpack_widgets(sync_data[name])
with self._lock_property(name, value):
setattr(self, name, value)
def _handle_custom_msg(self, content):
"""Called when a custom msg is received."""
self._msg_callbacks(self, content)
def _handle_property_changed(self, name, old, new):
"""Called when a property has been changed."""
# Make sure this isn't information that the front-end just sent us.
if self._should_send_property(name, new):
# Send new state to front-end
self.send_state(key=name)
def _handle_displayed(self, **kwargs):
"""Called when a view has been displayed for this widget instance"""
self._display_callbacks(self, **kwargs)
def _pack_widgets(self, x):
"""Recursively converts all widget instances to model id strings.
Children widgets will be stored and transmitted to the front-end by
their model ids. Return value must be JSON-able."""
if isinstance(x, dict):
return {k: self._pack_widgets(v) for k, v in x.items()}
elif isinstance(x, (list, tuple)):
return [self._pack_widgets(v) for v in x]
elif isinstance(x, Widget):
return x.model_id
else:
return x # Value must be JSON-able
def _unpack_widgets(self, x):
"""Recursively converts all model id strings to widget instances.
Children widgets will be stored and transmitted to the front-end by
their model ids."""
if isinstance(x, dict):
return {k: self._unpack_widgets(v) for k, v in x.items()}
elif isinstance(x, (list, tuple)):
return [self._unpack_widgets(v) for v in x]
elif isinstance(x, string_types):
return x if x not in Widget.widgets else Widget.widgets[x]
else:
return x
def _ipython_display_(self, **kwargs):
"""Called when `IPython.display.display` is called on the widget."""
# Show view. By sending a display message, the comm is opened and the
# initial state is sent.
self._send({"method": "display"})
self._handle_displayed(**kwargs)
def _send(self, msg):
"""Sends a message to the model in the front-end."""
self.comm.send(msg)
class DOMWidget(Widget):
visible = Bool(True, help="Whether the widget is visible.", sync=True)
_css = Dict(sync=True) # Internal CSS property dict
def get_css(self, key, selector=""):
"""Get a CSS property of the widget.
Note: This function does not actually request the CSS from the
front-end; Only properties that have been set with set_css can be read.
Parameters
----------
key: unicode
CSS key
selector: unicode (optional)
JQuery selector used when the CSS key/value was set.
"""
if selector in self._css and key in self._css[selector]:
return self._css[selector][key]
else:
return None
def set_css(self, dict_or_key, value=None, selector=''):
"""Set one or more CSS properties of the widget.
This function has two signatures:
- set_css(css_dict, selector='')
- set_css(key, value, selector='')
Parameters
----------
css_dict : dict
CSS key/value pairs to apply
key: unicode
CSS key
value:
CSS value
selector: unicode (optional, kwarg only)
JQuery selector to use to apply the CSS key/value. If no selector
is provided, an empty selector is used. An empty selector makes the
front-end try to apply the css to a default element. The default
element is an attribute unique to each view, which is a DOM element
of the view that should be styled with common CSS (see
`$el_to_style` in the Javascript code).
"""
if not selector in self._css:
self._css[selector] = {}
my_css = self._css[selector]
if value is None:
css_dict = dict_or_key
else:
css_dict = {dict_or_key: value}
for (key, value) in css_dict.items():
if not (key in my_css and value == my_css[key]):
my_css[key] = value
self.send_state('_css')
def add_class(self, class_names, selector=""):
"""Add class[es] to a DOM element.
Parameters
----------
class_names: unicode or list
Class name(s) to add to the DOM element(s).
selector: unicode (optional)
JQuery selector to select the DOM element(s) that the class(es) will
be added to.
"""
class_list = class_names
if isinstance(class_list, (list, tuple)):
class_list = ' '.join(class_list)
self.send({
"msg_type" : "add_class",
"class_list" : class_list,
"selector" : selector
})
def remove_class(self, class_names, selector=""):
"""Remove class[es] from a DOM element.
Parameters
----------
class_names: unicode or list
Class name(s) to remove from the DOM element(s).
selector: unicode (optional)
JQuery selector to select the DOM element(s) that the class(es) will
be removed from.
"""
class_list = class_names
if isinstance(class_list, (list, tuple)):
class_list = ' '.join(class_list)
self.send({
"msg_type" : "remove_class",
"class_list" : class_list,
"selector" : selector,
})
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