Adding event hooks for the GUI

CHANGES.rst

@@ -22,6 +22,7 @@ Release History
 0.4.4 (unreleased)
 ==================
 
+- Improvement (Experimental): Added simulator hooks
 - Improvement: Added audible spike sounds
 - Improvement (Experimental): Nodes have access to the GUI keyboard state
 - Improvement: support for nengo-bio Connections

nengo_gui/components/sim_control.py

@@ -190,11 +190,16 @@ def javascript(self):
     def message(self, msg):
         if msg == 'pause':
             self.paused = True
+            if 'on_pause' in self.page.locals:
+                self.page.locals['on_pause'](self.page.sim)
         elif msg == 'config':
             self.send_config_options = True
         elif msg == 'continue':
             if self.page.sim is None:
                 self.page.rebuild = True
+            else:
+                if 'on_continue' in self.page.locals:
+                    self.page.locals['on_continue'](self.page.sim)
             self.paused = False
         elif msg == 'reset':
             self.paused = True

nengo_gui/guibackend.py

@@ -460,6 +460,7 @@ def create_page(self, filename, reset_cfg=False):
 
     def remove_page(self, page):
         self._last_access = time.time()
+        page.close()
         self.pages.remove(page)
         if (not self._shutting_down and self.settings.auto_shutdown > 0 and
                 len(self.pages) <= 0):

nengo_gui/page.py

@@ -498,6 +498,8 @@ def build(self):
             if self.sim is not None:
                 if self.settings.backend in Page.singleton_sims:
                     Page.singleton_sims[self.settings.backend] = self
+                if 'on_start' in self.locals:
+                    self.locals['on_start'](self.sim)
 
             # remove the temporary components added for visualization
             for c in self.components:
@@ -520,15 +522,25 @@ def runner(self):
                         self.sim.run_steps(self.sim.max_steps)
                     else:
                         self.sim.step()
+                        if 'on_step' in self.locals:
+                            self.locals['on_step'](self.sim)
                 except Exception as err:
                     if self.finished:
                         return
                     line = nengo_gui.exec_env.determine_line_number()
                     self.error = dict(trace=traceback.format_exc(), line=line)
                     self.sim = None
             while self.sims_to_close:
-                self.sims_to_close.pop().close()
+                s = self.sims_to_close.pop()
+                if 'on_close' in self.locals:
+                    self.locals['on_close'](s)
+                s.close()
 
             if self.rebuild:
                 self.build()
         self.sim = None
+
+    def close(self):
+        if self.sim is not None:
+            if 'on_close' in self.locals:
+                self.locals['on_close'](self.sim)