FIX : first pass at fixing nbagg close issue

Add callback to destroy figure when the user hits the red x
in the notebook.

This is not the correct solution, but it (might) work for now.

Author: tacaswell

lib/matplotlib/backends/backend_nbagg.py

@@ -231,13 +231,22 @@ def new_figure_manager_given_figure(num, figure):
     """
     Create a new figure manager instance for the given figure.
     """
+    from .._pylab_helpers import Gcf
+
+    def closer(event):
+        Gcf.destroy(num)
+
     canvas = FigureCanvasNbAgg(figure)
     if rcParams['nbagg.transparent']:
         figure.patch.set_alpha(0)
     manager = FigureManagerNbAgg(canvas, num)
+
     if is_interactive():
         manager.show()
         figure.canvas.draw_idle()
+
+    canvas.mpl_connect('close_event', closer)
+
     return manager
 
 
@@ -298,6 +307,7 @@ def on_message(self, message):
         message = json.loads(message['content']['data'])
         if message['type'] == 'closing':
             self.on_close()
+            self.manager.canvas.close_event()
         elif message['type'] == 'supports_binary':
             self.supports_binary = message['value']
         else:

lib/matplotlib/backends/backend_webagg_core.py

@@ -329,6 +329,7 @@ def handle_event(self, event):
             self.send_event('figure_label', label=figure_label)
             self._force_full = True
             self.draw_idle()
+
         else:
             handler = getattr(self, 'handle_{0}'.format(e_type), None)
             if handler is None: