Extended the nbagg backend to support animation.

Author: pelson

lib/matplotlib/backends/backend_nbagg.py

@@ -5,31 +5,32 @@
 import os
 from uuid import uuid4 as uuid
 
+import tornado.ioloop
+
 from IPython.display import display, Javascript, HTML
 from IPython.kernel.comm import Comm
 
 from matplotlib.figure import Figure
 from matplotlib.backends.backend_webagg_core import (FigureManagerWebAgg,
                                                      FigureCanvasWebAggCore,
                                                      NavigationToolbar2WebAgg)
-from matplotlib.backend_bases import ShowBase, NavigationToolbar2
+from matplotlib.backend_bases import ShowBase, NavigationToolbar2, TimerBase
 
 
 class Show(ShowBase):
     def __call__(self, block=None):
-        import matplotlib._pylab_helpers as pylab_helpers
+        from matplotlib._pylab_helpers import Gcf
         from matplotlib import is_interactive
 
-        managers = pylab_helpers.Gcf.get_all_fig_managers()
+        managers = Gcf.get_all_fig_managers()
         if not managers:
             return
 
-        interactive = is_interactive()
-
         for manager in managers:
             manager.show()
-            if not interactive and manager in pylab_helpers.Gcf._activeQue:
-                pylab_helpers.Gcf._activeQue.remove(manager)
+
+        if not is_interactive() and manager in Gcf._activeQue:
+            Gcf._activeQue.remove(manager)
 
 
 show = Show()
@@ -48,19 +49,18 @@ def draw_if_interactive():
 def connection_info():
     """
     Return a string showing the figure and connection status for
-    the backend.
+    the backend. This is intended as a diagnostic tool, and not for general
+    use.
 
     """
-    # TODO: Make this useful!
-    import matplotlib._pylab_helpers as pylab_helpers
+    from matplotlib._pylab_helpers import Gcf
     result = []
-    for manager in pylab_helpers.Gcf.get_all_fig_managers():
+    for manager in Gcf.get_all_fig_managers():
         fig = manager.canvas.figure
         result.append('{} - {}'.format((fig.get_label() or
                                         "Figure {0}".format(manager.num)),
                                        manager.web_sockets))
-    result.append('Figures pending show: ' +
-                  str(len(pylab_helpers.Gcf._activeQue)))
+    result.append('Figures pending show: {}'.format(len(Gcf._activeQue)))
     return '\n'.join(result)
 
 
@@ -93,7 +93,8 @@ def __init__(self, canvas, num):
 
     def display_js(self):
         # XXX How to do this just once? It has to deal with multiple
-        # browser instances using the same kernel.
+        # browser instances using the same kernel (require.js - but the
+        # file isn't static?).
         display(Javascript(FigureManagerNbAgg.get_javascript()))
 
     def show(self):
@@ -105,6 +106,10 @@ def show(self):
         self._shown = True
 
     def reshow(self):
+        """
+        A special method to re-show the figure in the notebook.
+
+        """
         self._shown = False
         self.show()
 
@@ -137,6 +142,43 @@ def destroy(self):
         for comm in self.web_sockets.copy():
             comm.on_close()
 
+    def clearup_closed(self):
+        """Clear up any closed Comms."""
+        self.web_sockets = set([socket for socket in self.web_sockets
+                                if not socket.is_open()])
+
+
+class TimerTornado(TimerBase):
+    def _timer_start(self):
+        import datetime
+        self._timer_stop()
+        if self._single:
+            ioloop = tornado.ioloop.IOLoop.instance()
+            self._timer = ioloop.add_timeout(
+                datetime.timedelta(milliseconds=self.interval),
+                self._on_timer)
+        else:
+            self._timer = tornado.ioloop.PeriodicCallback(
+                self._on_timer,
+                self.interval)
+        self._timer.start()
+
+    def _timer_stop(self):
+        if self._timer is not None:
+            self._timer.stop()
+            self._timer = None
+
+    def _timer_set_interval(self):
+        # Only stop and restart it if the timer has already been started
+        if self._timer is not None:
+            self._timer_stop()
+            self._timer_start()
+
+
+class FigureCanvasNbAgg(FigureCanvasWebAggCore):
+    def new_timer(self, *args, **kwargs):
+        return TimerTornado(*args, **kwargs)
+
 
 def new_figure_manager(num, *args, **kwargs):
     """
@@ -151,7 +193,7 @@ def new_figure_manager_given_figure(num, figure):
     """
     Create a new figure manager instance for the given figure.
     """
-    canvas = FigureCanvasWebAggCore(figure)
+    canvas = FigureCanvasNbAgg(figure)
     manager = FigureManagerNbAgg(canvas, num)
     return manager
 
@@ -170,6 +212,8 @@ def __init__(self, manager):
         self.supports_binary = None
         self.manager = manager
         self.uuid = str(uuid())
+        # Publish an output area with a unique ID. The javascript can then
+        # hook into this area.
         display(HTML("<div id=%r></div>" % self.uuid))
         try:
             self.comm = Comm('matplotlib', data={'id': self.uuid})
@@ -178,12 +222,17 @@ def __init__(self, manager):
                                'instance. Are you in the IPython notebook?')
         self.comm.on_msg(self.on_message)
 
+        manager = self.manager
+        self.comm.on_close(lambda close_message: manager.clearup_closed())
+
+    def is_open(self):
+        return not self.comm._closed
+
     def on_close(self):
         # When the socket is closed, deregister the websocket with
         # the FigureManager.
-        if self.comm in self.manager.web_sockets:
-            self.manager.remove_web_socket(self)
         self.comm.close()
+        self.manager.clearup_closed()
 
     def send_json(self, content):
         self.comm.send({'data': json.dumps(content)})

lib/matplotlib/backends/backend_webagg.py

@@ -39,6 +39,7 @@
 from matplotlib.figure import Figure
 from matplotlib._pylab_helpers import Gcf
 from . import backend_webagg_core as core
+from . import backend_nbagg
 
 
 def new_figure_manager(num, *args, **kwargs):
@@ -96,39 +97,13 @@ def run(self):
 webagg_server_thread = ServerThread()
 
 
-class TimerTornado(backend_bases.TimerBase):
-    def _timer_start(self):
-        self._timer_stop()
-        if self._single:
-            ioloop = tornado.ioloop.IOLoop.instance()
-            self._timer = ioloop.add_timeout(
-                datetime.timedelta(milliseconds=self.interval),
-                self._on_timer)
-        else:
-            self._timer = tornado.ioloop.PeriodicCallback(
-                self._on_timer,
-                self.interval)
-        self._timer.start()
-
-    def _timer_stop(self):
-        if self._timer is not None:
-            self._timer.stop()
-            self._timer = None
-
-    def _timer_set_interval(self):
-        # Only stop and restart it if the timer has already been started
-        if self._timer is not None:
-            self._timer_stop()
-            self._timer_start()
-
-
 class FigureCanvasWebAgg(core.FigureCanvasWebAggCore):
     def show(self):
         # show the figure window
         show()
 
     def new_timer(self, *args, **kwargs):
-        return TimerTornado(*args, **kwargs)
+        return backend_nbagg.TimerTornado(*args, **kwargs)
 
     def start_event_loop(self, timeout):
         backend_bases.FigureCanvasBase.start_event_loop_default(

lib/matplotlib/backends/web_backend/nbagg_mpl.js

@@ -25,6 +25,8 @@ mpl.mpl_figure_comm = function(comm, msg) {
     // starts-up an IPython Comm through the "matplotlib" channel.
 
     var id = msg.content.data.id;
+    // Get hold of the div created by the display call when the Comm
+    // socket was opened in Python.
     var element = $("#" + id);
     var ws_proxy = comm_websocket_adapter(comm)
 
@@ -44,7 +46,7 @@ mpl.mpl_figure_comm = function(comm, msg) {
 
     // Disable right mouse context menu.
     $(fig.rubberband_canvas).bind("contextmenu",function(e){
-              return false;
+        return false;
     });
 
 };
@@ -59,6 +61,7 @@ mpl.figure.prototype.handle_close = function(fig, msg) {
 }
 
 mpl.figure.prototype.push_to_output = function(remove_interactive) {
+    // Turn the data on the canvas into data in the output cell.
     var dataURL = this.canvas.toDataURL();
     this.cell_info[1]['text/html'] = '<img src="' + dataURL + '">';
 }