Added widget.py

IPython/html/widgets/__init__.py

@@ -0,0 +1,1 b''
+from widget import Widget
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IPython/html/widgets/widget.py

@@ -0,0 +1,148 b''
+from IPython.kernel.comm import Comm
+from IPython.config import LoggingConfigurable
+from IPython.utils.traitlets import Unicode, Float, Bool, Dict
+from IPython.display import clear_output
+
+from copy import copy
+import uuid
+import sys
+
+
+class Widget(Comm):
+    
+    ### Public declarations
+    target_name = Unicode('widget')
+    default_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
+        
+        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 show(self, view_name=None):
+        if not view_name:
+            view_name = self.default_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.show()
+            
+    
+    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})
+    
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