notebook/IPython/html/widgets/widget.py
Jonathan Frederic 22dcf3aa68 Basic display logic
s/show/_repr_...
Added code to display Javascript in frontend.
2014-01-16 10:55:57 +00:00

156 lines
4.3 KiB
Python

from copy import copy
import uuid
import sys
from IPython.kernel.comm import Comm
from IPython.config import LoggingConfigurable
from IPython.utils.traitlets import Unicode, Dict
from IPython.display import Javascript, display
class Widget(Comm):
### Public declarations
target_name = Unicode('widget')
view_name = Unicode()
### Private/protected declarations
_keys = []
_property_lock = False
_parent = None
_children = []
_css = Dict()
### Public constructor
def __init__(self, parent=None, **kwargs):
super(Widget, self).__init__(**kwargs)
self._children = []
if parent is not None:
parent._children.append(self)
self._parent = parent
# Send frontend type code.
display(Javascript(data=self._get_backbone_js()))
# Create a comm.
self.comm = Comm(target_name=self.target_name)
self.comm.on_msg(self._handle_msg)
# Register after init to allow default values to be specified
self.on_trait_change(self._handle_property_changed, self.keys)
# Set initial properties on client model.
self.send_state()
def __del__(self):
self.close()
def close(self):
self.comm.close()
del self.comm
### Properties
def _get_parent(self):
return self._parent
parent = property(_get_parent)
def _get_children(self):
return copy(self._children)
children = property(_get_children)
def _get_keys(self):
keys = ['_css']
keys.extend(self._keys)
return keys
keys = property(_get_keys)
def _get_css(self, key, selector=""):
if selector in self._css and key in self._css[selector]:
return self._css[selector][key]
else:
return None
def _set_css(self, value, key, selector=""):
if selector not in self._css:
self._css[selector] = {}
# Only update the property if it has changed.
if not (key in self._css[selector] and value in self._css[selector][key]):
self._css[selector][key] = value
self.send_state() # Send new state to client.
css = property(_get_css, _set_css)
### Event handlers
def _handle_msg(self, msg):
# Handle backbone sync methods
sync_method = msg['content']['data']['sync_method']
sync_data = msg['content']['data']['sync_data']
if sync_method.lower() in ['create', 'update']:
self._handle_recieve_state(sync_data)
def _handle_recieve_state(self, sync_data):
self._property_lock = True
try:
# Use _keys instead of keys - Don't get retrieve the css from the client side.
for name in self._keys:
if name in sync_data:
setattr(self, name, sync_data[name])
finally:
self._property_lock = False
def _handle_property_changed(self, name, old, new):
if not self._property_lock:
# TODO: Validate properties.
# Send new state to frontend
self.send_state()
### Public methods
def _repr_widget_(self):
view_name = self.view_name
if not view_name:
view_name = self.target_name
# Make sure model is syncronized
self.send_state()
# Show view.
if self.parent is None:
self.comm.send({"method": "show", "view_name": view_name})
else:
self.comm.send({"method": "show",
"view_name": view_name,
"parent": self.parent.comm.comm_id})
# Now show children if any.
for child in self.children:
child._repr_widget_()
return self._get_backbone_js
def send_state(self):
state = {}
for key in self.keys:
try:
state[key] = getattr(self, key)
except Exception as e:
pass # Eat errors, nom nom nom
self.comm.send({"method": "update",
"state": state})
### Private methods
def _get_backbone_js(self):
return 'alert("woohoo!");'