add Kernel-side widgets

IPython/kernel/widgets/__init__.py

@@ -0,0 +1,2 b''
+from .manager import *
+from .widget import *

IPython/kernel/widgets/manager.py

@@ -0,0 +1,115 b''
+"""Base class to manage widgets"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2013  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from weakref import ref
+
+from IPython.config import LoggingConfigurable
+from IPython.core.prompts import LazyEvaluate
+from IPython.core.getipython import get_ipython
+from IPython.utils.traitlets import Instance, Unicode, Dict, Any
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+
+def lazy_keys(dikt):
+    """Return lazy-evaluated string representation of a dictionary's keys
+    
+    Key list is only constructed if it will actually be used.
+    Used for debug-logging.
+    """
+    return LazyEvaluate(lambda d: list(d.keys()))
+
+class WidgetManager(LoggingConfigurable):
+    """Manager for Widgets in the Kernel"""
+    
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    def _shell_default(self):
+        return get_ipython()
+    iopub_socket = Any()
+    def _iopub_socket_default(self):
+        return self.shell.parent.iopub_socket
+    session = Instance('IPython.kernel.zmq.session.Session')
+    def _session_default(self):
+        if self.shell is None:
+            return
+        return self.shell.parent.session
+    
+    widgets = Dict()
+    
+    # Public APIs
+    
+    def register_widget(self, widget):
+        """Register a new widget"""
+        self.widgets[widget.widget_id] = ref(widget)
+        widget.shell = self.shell
+        widget.iopub_socket = self.iopub_socket
+        widget.create()
+        return widget.widget_id
+    
+    def unregister_widget(self, widget_id):
+        """Unregister a widget, and destroy its counterpart"""
+        # unlike get_widget, this should raise a KeyError
+        widget_ref = self.widgets.pop(widget_id)
+        widget = widget_ref()
+        if widget is None:
+            # already destroyed, nothing to do
+            return
+        widget.destroy()
+    
+    def get_widget(self, widget_id):
+        """Get a widget with a particular id
+        
+        Returns the widget if found, otherwise None.
+        
+        This will not raise an error,
+        it will log messages if the widget cannot be found.
+        """
+        if widget_id not in self.widgets:
+            self.log.error("No such widget: %s", widget_id)
+            self.log.debug("Current widgets: %s", lazy_keys(self.widgets))
+            return
+        # call, because we store weakrefs
+        widget = self.widgets[widget_id]()
+        if widget is None:
+            self.log.error("Widget %s has been removed", widget_id)
+            del self.widgets[widget_id]
+            self.log.debug("Current widgets: %s", lazy_keys(self.widgets))
+            return
+        return widget
+    
+    # Message handlers
+    
+    def widget_update(self, stream, ident, msg):
+        """Handler for widget_update messages"""
+        content = msg['content']
+        widget_id = content['widget_id']
+        widget = self.get_widget(widget_id)
+        if widget is None:
+            # no such widget
+            return
+        widget.handle_update(content['data'])
+    
+    def widget_destroy(self, stream, ident, msg):
+        """Handler for widget_destroy messages"""
+        content = msg['content']
+        widget_id = content['widget_id']
+        widget = self.get_widget(widget_id)
+        if widget is None:
+            # no such widget
+            return
+        widget.handle_destroy(content['data'])
+        del self.widgets[widget_id]
+    
+
+__all__ = ['WidgetManager']

IPython/kernel/widgets/widget.py

@@ -0,0 +1,92 b''
+"""Base class for a Widget"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2013  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import uuid
+
+from IPython.config import LoggingConfigurable
+from IPython.utils.traitlets import Instance, Unicode, Bytes, Bool, Dict, Any
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+
+class Widget(LoggingConfigurable):
+    
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    def _shell_default(self):
+        return get_ipython()
+    iopub_socket = Any()
+    def _iopub_socket_default(self):
+        return self.shell.parent.iopub_socket
+    session = Instance('IPython.kernel.zmq.session.Session')
+    def _session_default(self):
+        if self.shell is None:
+            return
+        return self.shell.parent.session
+    
+    topic = Bytes()
+    def _topic_default(self):
+        return ('widget-%s' % self.widget_id).encode('ascii')
+    
+    _destroy_data = Dict(help="data dict, if any, to be included in widget_destroy")
+    _create_data = Dict(help="data dict, if any, to be included in widget_create")
+    
+    _destroyed = Bool(False)
+    widget_type = Unicode('widget')
+    widget_id = Unicode()
+    def _widget_id_default(self):
+        return uuid.uuid4().hex
+    
+    def _publish_msg(self, msg_type, data=None, **keys):
+        """Helper for sending a widget message on IOPub"""
+        data = {} if data is None else data
+        self.session.send(self.iopub_socket, msg_type,
+            dict(data=data, widget_id=self.widget_id, **keys),
+            ident=self.topic,
+        )
+    
+    def __del__(self):
+        """trigger destroy on gc"""
+        self.destroy()
+    
+    # publishing messages
+    
+    def create(self):
+        """Create the frontend-side version of this widget"""
+        self._publish_msg('widget_create', self._create_data, widget_type = self.widget_type)
+    
+    def destroy(self):
+        """Destroy the frontend-side version of this widget"""
+        if self._destroyed:
+            # only destroy once
+            return
+        self._publish_msg('widget_destroy', self._destroy_data)
+        self._destroyed = True
+    
+    def update(self, data=None):
+        """Update the frontend-side version of this widget"""
+        self._publish_msg('widget_update', data)
+    
+    # handling of incoming messages
+    
+    def handle_destroy(self, data):
+        """Handle a widget_destroy message"""
+        self.log.debug("handle_destroy %s", data)
+    
+    def handle_update(self, data):
+        """Handle a widget_update message"""
+        self.log.debug("handle_update %s", data)
+        self.update_data = data
+
+
+__all__ = ['Widget']

IPython/core/interactiveshell.py

@@ -507,6 +507,7 b' class InteractiveShell(SingletonConfigurable):'
         self.init_pdb()
         self.init_extension_manager()
         self.init_payload()
+        self.init_widgets()
         self.hooks.late_startup_hook()
         atexit.register(self.atexit_operations)
 
@@ -2319,6 +2320,14 b' class InteractiveShell(SingletonConfigurable):'
         self.configurables.append(self.payload_manager)
 
     #-------------------------------------------------------------------------
+    # Things related to widgets
+    #-------------------------------------------------------------------------
+    
+    def init_widgets(self):
+        # not implemented in the base class
+        pass
+    
+    #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 

IPython/kernel/zmq/ipkernel.py

@@ -168,11 +168,17 b' class Kernel(Configurable):'
         for msg_type in msg_types:
             self.shell_handlers[msg_type] = getattr(self, msg_type)
         
+        widget_msg_types = [ 'widget_update', 'widget_destroy' ]
+        widget_manager = self.shell.widget_manager
+        for msg_type in widget_msg_types:
+            self.shell_handlers[msg_type] = getattr(widget_manager, msg_type)
+        
         control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
         self.control_handlers = {}
         for msg_type in control_msg_types:
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
+
     def dispatch_control(self, msg):
         """dispatch control requests"""
         idents,msg = self.session.feed_identities(msg, copy=False)

IPython/kernel/zmq/zmqshell.py

@@ -49,6 +49,7 b' from IPython.utils.warn import error'
 from IPython.kernel.zmq.displayhook import ZMQShellDisplayHook
 from IPython.kernel.zmq.datapub import ZMQDataPublisher
 from IPython.kernel.zmq.session import extract_header
+from IPython.kernel.widgets import WidgetManager
 from session import Session
 
 #-----------------------------------------------------------------------------
@@ -594,6 +595,9 b' class ZMQInteractiveShell(InteractiveShell):'
         self.register_magics(KernelMagics)
         self.magics_manager.register_alias('ed', 'edit')
 
+    def init_widgets(self):
+        self.widget_manager = WidgetManager(shell=self, parent=self)
+        self.configurables.append(self.widget_manager)
 
 
 InteractiveShellABC.register(ZMQInteractiveShell)