Moves terminal websocket handling back to Jupyter Server

jupyter#31 moved a bit too much from jupyter server to nbclassic. This moves some back. See also jupyter-server/jupyter_server#314

nbclassic/notebookapp.py

@@ -49,7 +49,7 @@
 )
 from jupyter_server.utils import url_path_join as ujoin
 
-from .terminal.handlers import TerminalHandler, TermSocket
+from .terminal.handlers import TerminalHandler
 
 
 #-----------------------------------------------------------------------------
@@ -217,18 +217,9 @@ def initialize_handlers(self):
         handlers.extend(load_handlers('nbclassic.edit.handlers'))
 
         # Add terminal handlers
-        try:
-            term_mgr = self.serverapp.web_app.settings['terminal_manager']
-        except KeyError:
-            pass  # Terminals not enabled
-        else:
-            handlers.append(
-                (r"/terminals/(\w+)", TerminalHandler)
-            )
-            handlers.append(
-                (r"/terminals/websocket/(\w+)", TermSocket,
-                {'term_manager': term_mgr})
-            )
+        handlers.append(
+            (r"/terminals/(\w+)", TerminalHandler)
+        )
 
         handlers.append(
             (r"/nbextensions/(.*)", FileFindHandler, {

nbclassic/terminal/handlers.py

@@ -5,10 +5,7 @@
 # Distributed under the terms of the Modified BSD License.
 
 from tornado import web
-import terminado
-from jupyter_server._tz import utcnow
 from jupyter_server.base.handlers import JupyterHandler
-from jupyter_server.base.zmqhandlers import WebSocketMixin
 from jupyter_server.extension.handler import (
     ExtensionHandlerMixin,
     ExtensionHandlerJinjaMixin
@@ -20,26 +17,3 @@ class TerminalHandler(ExtensionHandlerJinjaMixin, ExtensionHandlerMixin, Jupyter
     def get(self, term_name):
         self.write(self.render_template('terminal.html',
                    ws_path="terminals/websocket/%s" % term_name))
-
-
-class TermSocket(WebSocketMixin, JupyterHandler, terminado.TermSocket):
-
-    def origin_check(self):
-        """Terminado adds redundant origin_check
-
-        Tornado already calls check_origin, so don't do anything here.
-        """
-        return True
-
-    def get(self, *args, **kwargs):
-        if not self.get_current_user():
-            raise web.HTTPError(403)
-        return super(TermSocket, self).get(*args, **kwargs)
-
-    def on_message(self, message):
-        super(TermSocket, self).on_message(message)
-        self.application.settings['terminal_last_activity'] = utcnow()
-
-    def write_message(self, message, binary=False):
-        super(TermSocket, self).write_message(message, binary=binary)
-        self.application.settings['terminal_last_activity'] = utcnow()