Show More
@@ -1,455 +1,455 b'' | |||
|
1 | 1 | """Base Widget class. Allows user to create widgets in the back-end that render |
|
2 | 2 | in the IPython notebook front-end. |
|
3 | 3 | """ |
|
4 | 4 | #----------------------------------------------------------------------------- |
|
5 | 5 | # Copyright (c) 2013, the IPython Development Team. |
|
6 | 6 | # |
|
7 | 7 | # Distributed under the terms of the Modified BSD License. |
|
8 | 8 | # |
|
9 | 9 | # The full license is in the file COPYING.txt, distributed with this software. |
|
10 | 10 | #----------------------------------------------------------------------------- |
|
11 | 11 | |
|
12 | 12 | #----------------------------------------------------------------------------- |
|
13 | 13 | # Imports |
|
14 | 14 | #----------------------------------------------------------------------------- |
|
15 | 15 | from contextlib import contextmanager |
|
16 | 16 | |
|
17 | 17 | from IPython.core.getipython import get_ipython |
|
18 | 18 | from IPython.kernel.comm import Comm |
|
19 | 19 | from IPython.config import LoggingConfigurable |
|
20 | 20 | from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, Tuple, Int |
|
21 | 21 | from IPython.utils.py3compat import string_types |
|
22 | 22 | |
|
23 | 23 | #----------------------------------------------------------------------------- |
|
24 | 24 | # Classes |
|
25 | 25 | #----------------------------------------------------------------------------- |
|
26 | 26 | class CallbackDispatcher(LoggingConfigurable): |
|
27 | 27 | """A structure for registering and running callbacks""" |
|
28 | 28 | callbacks = List() |
|
29 | 29 | |
|
30 | 30 | def __call__(self, *args, **kwargs): |
|
31 | 31 | """Call all of the registered callbacks.""" |
|
32 | 32 | value = None |
|
33 | 33 | for callback in self.callbacks: |
|
34 | 34 | try: |
|
35 | 35 | local_value = callback(*args, **kwargs) |
|
36 | 36 | except Exception as e: |
|
37 | 37 | ip = get_ipython() |
|
38 | 38 | if ip is None: |
|
39 | 39 | self.log.warn("Exception in callback %s: %s", callback, e, exc_info=True) |
|
40 | 40 | else: |
|
41 | 41 | ip.showtraceback() |
|
42 | 42 | else: |
|
43 | 43 | value = local_value if local_value is not None else value |
|
44 | 44 | return value |
|
45 | 45 | |
|
46 | 46 | def register_callback(self, callback, remove=False): |
|
47 | 47 | """(Un)Register a callback |
|
48 | 48 | |
|
49 | 49 | Parameters |
|
50 | 50 | ---------- |
|
51 | 51 | callback: method handle |
|
52 | 52 | Method to be registered or unregistered. |
|
53 | 53 | remove=False: bool |
|
54 | 54 | Whether to unregister the callback.""" |
|
55 | 55 | |
|
56 | 56 | # (Un)Register the callback. |
|
57 | 57 | if remove and callback in self.callbacks: |
|
58 | 58 | self.callbacks.remove(callback) |
|
59 | 59 | elif not remove and callback not in self.callbacks: |
|
60 | 60 | self.callbacks.append(callback) |
|
61 | 61 | |
|
62 | 62 | def _show_traceback(method): |
|
63 | 63 | """decorator for showing tracebacks in IPython""" |
|
64 | 64 | def m(self, *args, **kwargs): |
|
65 | 65 | try: |
|
66 | 66 | return(method(self, *args, **kwargs)) |
|
67 | 67 | except Exception as e: |
|
68 | 68 | ip = get_ipython() |
|
69 | 69 | if ip is None: |
|
70 | 70 | self.log.warn("Exception in widget method %s: %s", method, e, exc_info=True) |
|
71 | 71 | else: |
|
72 | 72 | ip.showtraceback() |
|
73 | 73 | return m |
|
74 | 74 | |
|
75 | 75 | class Widget(LoggingConfigurable): |
|
76 | 76 | #------------------------------------------------------------------------- |
|
77 | 77 | # Class attributes |
|
78 | 78 | #------------------------------------------------------------------------- |
|
79 | 79 | _widget_construction_callback = None |
|
80 | 80 | widgets = {} |
|
81 | 81 | |
|
82 | 82 | @staticmethod |
|
83 | 83 | def on_widget_constructed(callback): |
|
84 | 84 | """Registers a callback to be called when a widget is constructed. |
|
85 | 85 | |
|
86 | 86 | The callback must have the following signature: |
|
87 | 87 | callback(widget)""" |
|
88 | 88 | Widget._widget_construction_callback = callback |
|
89 | 89 | |
|
90 | 90 | @staticmethod |
|
91 | 91 | def _call_widget_constructed(widget): |
|
92 | 92 | """Static method, called when a widget is constructed.""" |
|
93 | 93 | if Widget._widget_construction_callback is not None and callable(Widget._widget_construction_callback): |
|
94 | 94 | Widget._widget_construction_callback(widget) |
|
95 | 95 | |
|
96 | 96 | #------------------------------------------------------------------------- |
|
97 | 97 | # Traits |
|
98 | 98 | #------------------------------------------------------------------------- |
|
99 | 99 | _model_name = Unicode('WidgetModel', help="""Name of the backbone model |
|
100 | 100 | registered in the front-end to create and sync this widget with.""") |
|
101 | 101 | _view_name = Unicode(help="""Default view registered in the front-end |
|
102 | 102 | to use to represent the widget.""", sync=True) |
|
103 | 103 | _comm = Instance('IPython.kernel.comm.Comm') |
|
104 | 104 | |
|
105 | 105 | msg_throttle = Int(3, sync=True, help="""Maximum number of msgs the |
|
106 | 106 | front-end can send before receiving an idle msg from the back-end.""") |
|
107 | 107 | |
|
108 | 108 | keys = List() |
|
109 | 109 | def _keys_default(self): |
|
110 | 110 | return [name for name in self.traits(sync=True)] |
|
111 | 111 | |
|
112 | 112 | _property_lock = Tuple((None, None)) |
|
113 | 113 | |
|
114 | 114 | _display_callbacks = Instance(CallbackDispatcher, ()) |
|
115 | 115 | _msg_callbacks = Instance(CallbackDispatcher, ()) |
|
116 | 116 | |
|
117 | 117 | #------------------------------------------------------------------------- |
|
118 | 118 | # (Con/de)structor |
|
119 | 119 | #------------------------------------------------------------------------- |
|
120 | 120 | def __init__(self, **kwargs): |
|
121 | 121 | """Public constructor""" |
|
122 | 122 | super(Widget, self).__init__(**kwargs) |
|
123 | 123 | |
|
124 | 124 | self.on_trait_change(self._handle_property_changed, self.keys) |
|
125 | 125 | Widget._call_widget_constructed(self) |
|
126 | 126 | |
|
127 | 127 | def __del__(self): |
|
128 | 128 | """Object disposal""" |
|
129 | 129 | self.close() |
|
130 | 130 | |
|
131 | 131 | #------------------------------------------------------------------------- |
|
132 | 132 | # Properties |
|
133 | 133 | #------------------------------------------------------------------------- |
|
134 | 134 | |
|
135 | 135 | @property |
|
136 | 136 | def comm(self): |
|
137 | 137 | """Gets the Comm associated with this widget. |
|
138 | 138 | |
|
139 | 139 | If a Comm doesn't exist yet, a Comm will be created automagically.""" |
|
140 | 140 | if self._comm is None: |
|
141 | 141 | # Create a comm. |
|
142 | 142 | self._comm = Comm(target_name=self._model_name) |
|
143 | 143 | self._comm.on_msg(self._handle_msg) |
|
144 | 144 | self._comm.on_close(self._close) |
|
145 | 145 | Widget.widgets[self.model_id] = self |
|
146 | 146 | |
|
147 | 147 | # first update |
|
148 | 148 | self.send_state() |
|
149 | 149 | return self._comm |
|
150 | 150 | |
|
151 | 151 | @property |
|
152 | 152 | def model_id(self): |
|
153 | 153 | """Gets the model id of this widget. |
|
154 | 154 | |
|
155 | 155 | If a Comm doesn't exist yet, a Comm will be created automagically.""" |
|
156 | 156 | return self.comm.comm_id |
|
157 | 157 | |
|
158 | 158 | #------------------------------------------------------------------------- |
|
159 | 159 | # Methods |
|
160 | 160 | #------------------------------------------------------------------------- |
|
161 | 161 | def _close(self): |
|
162 | 162 | """Private close - cleanup objects, registry entries""" |
|
163 | 163 | del Widget.widgets[self.model_id] |
|
164 | 164 | self._comm = None |
|
165 | 165 | |
|
166 | 166 | def close(self): |
|
167 | 167 | """Close method. |
|
168 | 168 | |
|
169 | 169 | Closes the widget which closes the underlying comm. |
|
170 | 170 | When the comm is closed, all of the widget views are automatically |
|
171 | 171 | removed from the front-end.""" |
|
172 | 172 | if self._comm is not None: |
|
173 | 173 | self._comm.close() |
|
174 | 174 | self._close() |
|
175 | 175 | |
|
176 | 176 | def send_state(self, key=None): |
|
177 | 177 | """Sends the widget state, or a piece of it, to the front-end. |
|
178 | 178 | |
|
179 | 179 | Parameters |
|
180 | 180 | ---------- |
|
181 | 181 | key : unicode (optional) |
|
182 | 182 | A single property's name to sync with the front-end. |
|
183 | 183 | """ |
|
184 | 184 | self._send({ |
|
185 | 185 | "method" : "update", |
|
186 | 186 | "state" : self.get_state() |
|
187 | 187 | }) |
|
188 | 188 | |
|
189 | 189 | def get_state(self, key=None): |
|
190 | 190 | """Gets the widget state, or a piece of it. |
|
191 | 191 | |
|
192 | 192 | Parameters |
|
193 | 193 | ---------- |
|
194 | 194 | key : unicode (optional) |
|
195 | 195 | A single property's name to get. |
|
196 | 196 | """ |
|
197 | 197 | keys = self.keys if key is None else [key] |
|
198 | 198 | state = {} |
|
199 | 199 | for k in keys: |
|
200 |
f = self.trait_metadata(k, ' |
|
|
200 | f = self.trait_metadata(k, 'serialize') | |
|
201 | 201 | value = getattr(self, k) |
|
202 | 202 | if f is not None: |
|
203 | 203 | state[k] = f(value) |
|
204 | 204 | else: |
|
205 | 205 | state[k] = self._serialize_trait(value) |
|
206 | 206 | return state |
|
207 | 207 | |
|
208 | 208 | def send(self, content): |
|
209 | 209 | """Sends a custom msg to the widget model in the front-end. |
|
210 | 210 | |
|
211 | 211 | Parameters |
|
212 | 212 | ---------- |
|
213 | 213 | content : dict |
|
214 | 214 | Content of the message to send. |
|
215 | 215 | """ |
|
216 | 216 | self._send({"method": "custom", "content": content}) |
|
217 | 217 | |
|
218 | 218 | def on_msg(self, callback, remove=False): |
|
219 | 219 | """(Un)Register a custom msg receive callback. |
|
220 | 220 | |
|
221 | 221 | Parameters |
|
222 | 222 | ---------- |
|
223 | 223 | callback: callable |
|
224 | 224 | callback will be passed two arguments when a message arrives:: |
|
225 | 225 | |
|
226 | 226 | callback(widget, content) |
|
227 | 227 | |
|
228 | 228 | remove: bool |
|
229 | 229 | True if the callback should be unregistered.""" |
|
230 | 230 | self._msg_callbacks.register_callback(callback, remove=remove) |
|
231 | 231 | |
|
232 | 232 | def on_displayed(self, callback, remove=False): |
|
233 | 233 | """(Un)Register a widget displayed callback. |
|
234 | 234 | |
|
235 | 235 | Parameters |
|
236 | 236 | ---------- |
|
237 | 237 | callback: method handler |
|
238 | 238 | Must have a signature of:: |
|
239 | 239 | |
|
240 | 240 | callback(widget, **kwargs) |
|
241 | 241 | |
|
242 | 242 | kwargs from display are passed through without modification. |
|
243 | 243 | remove: bool |
|
244 | 244 | True if the callback should be unregistered.""" |
|
245 | 245 | self._display_callbacks.register_callback(callback, remove=remove) |
|
246 | 246 | |
|
247 | 247 | #------------------------------------------------------------------------- |
|
248 | 248 | # Support methods |
|
249 | 249 | #------------------------------------------------------------------------- |
|
250 | 250 | @contextmanager |
|
251 | 251 | def _lock_property(self, key, value): |
|
252 | 252 | """Lock a property-value pair. |
|
253 | 253 | |
|
254 | 254 | NOTE: This, in addition to the single lock for all state changes, is |
|
255 | 255 | flawed. In the future we may want to look into buffering state changes |
|
256 | 256 | back to the front-end.""" |
|
257 | 257 | self._property_lock = (key, value) |
|
258 | 258 | try: |
|
259 | 259 | yield |
|
260 | 260 | finally: |
|
261 | 261 | self._property_lock = (None, None) |
|
262 | 262 | |
|
263 | 263 | def _should_send_property(self, key, value): |
|
264 | 264 | """Check the property lock (property_lock)""" |
|
265 | 265 | return key != self._property_lock[0] or \ |
|
266 | 266 | value != self._property_lock[1] |
|
267 | 267 | |
|
268 | 268 | # Event handlers |
|
269 | 269 | @_show_traceback |
|
270 | 270 | def _handle_msg(self, msg): |
|
271 | 271 | """Called when a msg is received from the front-end""" |
|
272 | 272 | data = msg['content']['data'] |
|
273 | 273 | method = data['method'] |
|
274 | 274 | if not method in ['backbone', 'custom']: |
|
275 | 275 | self.log.error('Unknown front-end to back-end widget msg with method "%s"' % method) |
|
276 | 276 | |
|
277 | 277 | # Handle backbone sync methods CREATE, PATCH, and UPDATE all in one. |
|
278 | 278 | if method == 'backbone' and 'sync_data' in data: |
|
279 | 279 | sync_data = data['sync_data'] |
|
280 | 280 | self._handle_receive_state(sync_data) # handles all methods |
|
281 | 281 | |
|
282 | 282 | # Handle a custom msg from the front-end |
|
283 | 283 | elif method == 'custom': |
|
284 | 284 | if 'content' in data: |
|
285 | 285 | self._handle_custom_msg(data['content']) |
|
286 | 286 | |
|
287 | 287 | def _handle_receive_state(self, sync_data): |
|
288 | 288 | """Called when a state is received from the front-end.""" |
|
289 | 289 | for name in self.keys: |
|
290 | 290 | if name in sync_data: |
|
291 |
f = self.trait_metadata(name, ' |
|
|
291 | f = self.trait_metadata(name, 'deserialize') | |
|
292 | 292 | if f is not None: |
|
293 | 293 | value = f(sync_data[name]) |
|
294 | 294 | else: |
|
295 |
value = self._ |
|
|
295 | value = self._deserialize_trait(sync_data[name]) | |
|
296 | 296 | with self._lock_property(name, value): |
|
297 | 297 | setattr(self, name, value) |
|
298 | 298 | |
|
299 | 299 | def _handle_custom_msg(self, content): |
|
300 | 300 | """Called when a custom msg is received.""" |
|
301 | 301 | self._msg_callbacks(self, content) |
|
302 | 302 | |
|
303 | 303 | def _handle_property_changed(self, name, old, new): |
|
304 | 304 | """Called when a property has been changed.""" |
|
305 | 305 | # Make sure this isn't information that the front-end just sent us. |
|
306 | 306 | if self._should_send_property(name, new): |
|
307 | 307 | # Send new state to front-end |
|
308 | 308 | self.send_state(key=name) |
|
309 | 309 | |
|
310 | 310 | def _handle_displayed(self, **kwargs): |
|
311 | 311 | """Called when a view has been displayed for this widget instance""" |
|
312 | 312 | self._display_callbacks(self, **kwargs) |
|
313 | 313 | |
|
314 | 314 | def _serialize_trait(self, x): |
|
315 | 315 | """Serialize a trait value to json |
|
316 | 316 | |
|
317 | 317 | Traverse lists/tuples and dicts and serialize their values as well. |
|
318 | 318 | Replace any widgets with their model_id |
|
319 | 319 | """ |
|
320 | 320 | if isinstance(x, dict): |
|
321 | 321 | return {k: self._serialize_trait(v) for k, v in x.items()} |
|
322 | 322 | elif isinstance(x, (list, tuple)): |
|
323 | 323 | return [self._serialize_trait(v) for v in x] |
|
324 | 324 | elif isinstance(x, Widget): |
|
325 | 325 | return "IPY_MODEL_" + x.model_id |
|
326 | 326 | else: |
|
327 | 327 | return x # Value must be JSON-able |
|
328 | 328 | |
|
329 |
def _ |
|
|
329 | def _deserialize_trait(self, x): | |
|
330 | 330 | """Convert json values to objects |
|
331 | 331 | |
|
332 | 332 | We explicitly support converting valid string widget UUIDs to Widget references. |
|
333 | 333 | """ |
|
334 | 334 | if isinstance(x, dict): |
|
335 |
return {k: self._ |
|
|
335 | return {k: self._deserialize_trait(v) for k, v in x.items()} | |
|
336 | 336 | elif isinstance(x, (list, tuple)): |
|
337 |
return [self._ |
|
|
337 | return [self._deserialize_trait(v) for v in x] | |
|
338 | 338 | elif isinstance(x, string_types) and x.startswith('IPY_MODEL_') and x[10:] in Widget.widgets: |
|
339 | 339 | # we want to support having child widgets at any level in a hierarchy |
|
340 | 340 | # trusting that a widget UUID will not appear out in the wild |
|
341 | 341 | return Widget.widgets[x] |
|
342 | 342 | else: |
|
343 | 343 | return x |
|
344 | 344 | |
|
345 | 345 | def _ipython_display_(self, **kwargs): |
|
346 | 346 | """Called when `IPython.display.display` is called on the widget.""" |
|
347 | 347 | # Show view. By sending a display message, the comm is opened and the |
|
348 | 348 | # initial state is sent. |
|
349 | 349 | self._send({"method": "display"}) |
|
350 | 350 | self._handle_displayed(**kwargs) |
|
351 | 351 | |
|
352 | 352 | def _send(self, msg): |
|
353 | 353 | """Sends a message to the model in the front-end.""" |
|
354 | 354 | self.comm.send(msg) |
|
355 | 355 | |
|
356 | 356 | |
|
357 | 357 | class DOMWidget(Widget): |
|
358 | 358 | visible = Bool(True, help="Whether the widget is visible.", sync=True) |
|
359 | 359 | _css = List(sync=True) # Internal CSS property list: (selector, key, value) |
|
360 | 360 | |
|
361 | 361 | def get_css(self, key, selector=""): |
|
362 | 362 | """Get a CSS property of the widget. |
|
363 | 363 | |
|
364 | 364 | Note: This function does not actually request the CSS from the |
|
365 | 365 | front-end; Only properties that have been set with set_css can be read. |
|
366 | 366 | |
|
367 | 367 | Parameters |
|
368 | 368 | ---------- |
|
369 | 369 | key: unicode |
|
370 | 370 | CSS key |
|
371 | 371 | selector: unicode (optional) |
|
372 | 372 | JQuery selector used when the CSS key/value was set. |
|
373 | 373 | """ |
|
374 | 374 | if selector in self._css and key in self._css[selector]: |
|
375 | 375 | return self._css[selector][key] |
|
376 | 376 | else: |
|
377 | 377 | return None |
|
378 | 378 | |
|
379 | 379 | def set_css(self, dict_or_key, value=None, selector=''): |
|
380 | 380 | """Set one or more CSS properties of the widget. |
|
381 | 381 | |
|
382 | 382 | This function has two signatures: |
|
383 | 383 | - set_css(css_dict, selector='') |
|
384 | 384 | - set_css(key, value, selector='') |
|
385 | 385 | |
|
386 | 386 | Parameters |
|
387 | 387 | ---------- |
|
388 | 388 | css_dict : dict |
|
389 | 389 | CSS key/value pairs to apply |
|
390 | 390 | key: unicode |
|
391 | 391 | CSS key |
|
392 | 392 | value: |
|
393 | 393 | CSS value |
|
394 | 394 | selector: unicode (optional, kwarg only) |
|
395 | 395 | JQuery selector to use to apply the CSS key/value. If no selector |
|
396 | 396 | is provided, an empty selector is used. An empty selector makes the |
|
397 | 397 | front-end try to apply the css to a default element. The default |
|
398 | 398 | element is an attribute unique to each view, which is a DOM element |
|
399 | 399 | of the view that should be styled with common CSS (see |
|
400 | 400 | `$el_to_style` in the Javascript code). |
|
401 | 401 | """ |
|
402 | 402 | if value is None: |
|
403 | 403 | css_dict = dict_or_key |
|
404 | 404 | else: |
|
405 | 405 | css_dict = {dict_or_key: value} |
|
406 | 406 | |
|
407 | 407 | for (key, value) in css_dict.items(): |
|
408 | 408 | # First remove the selector/key pair from the css list if it exists. |
|
409 | 409 | # Then add the selector/key pair and new value to the bottom of the |
|
410 | 410 | # list. |
|
411 | 411 | self._css = [x for x in self._css if not (x[0]==selector and x[1]==key)] |
|
412 | 412 | self._css += [(selector, key, value)] |
|
413 | 413 | self.send_state('_css') |
|
414 | 414 | |
|
415 | 415 | def add_class(self, class_names, selector=""): |
|
416 | 416 | """Add class[es] to a DOM element. |
|
417 | 417 | |
|
418 | 418 | Parameters |
|
419 | 419 | ---------- |
|
420 | 420 | class_names: unicode or list |
|
421 | 421 | Class name(s) to add to the DOM element(s). |
|
422 | 422 | selector: unicode (optional) |
|
423 | 423 | JQuery selector to select the DOM element(s) that the class(es) will |
|
424 | 424 | be added to. |
|
425 | 425 | """ |
|
426 | 426 | class_list = class_names |
|
427 | 427 | if isinstance(class_list, (list, tuple)): |
|
428 | 428 | class_list = ' '.join(class_list) |
|
429 | 429 | |
|
430 | 430 | self.send({ |
|
431 | 431 | "msg_type" : "add_class", |
|
432 | 432 | "class_list" : class_list, |
|
433 | 433 | "selector" : selector |
|
434 | 434 | }) |
|
435 | 435 | |
|
436 | 436 | def remove_class(self, class_names, selector=""): |
|
437 | 437 | """Remove class[es] from a DOM element. |
|
438 | 438 | |
|
439 | 439 | Parameters |
|
440 | 440 | ---------- |
|
441 | 441 | class_names: unicode or list |
|
442 | 442 | Class name(s) to remove from the DOM element(s). |
|
443 | 443 | selector: unicode (optional) |
|
444 | 444 | JQuery selector to select the DOM element(s) that the class(es) will |
|
445 | 445 | be removed from. |
|
446 | 446 | """ |
|
447 | 447 | class_list = class_names |
|
448 | 448 | if isinstance(class_list, (list, tuple)): |
|
449 | 449 | class_list = ' '.join(class_list) |
|
450 | 450 | |
|
451 | 451 | self.send({ |
|
452 | 452 | "msg_type" : "remove_class", |
|
453 | 453 | "class_list" : class_list, |
|
454 | 454 | "selector" : selector, |
|
455 | 455 | }) |
General Comments 0
You need to be logged in to leave comments.
Login now