bug when navigation was not defined

Author: fariza

examples/user_interfaces/navigation.py

@@ -52,8 +52,8 @@ def trigger(self, event):
 fig.canvas.manager.navigation.add_tool('List', ListTools)
 if matplotlib.rcParams['backend'] == 'GTK3Cairo':
     fig.canvas.manager.navigation.add_tool('copy', CopyToolGTK3)
-
+ 
 # Just for fun, lets remove the back button
-# fig.canvas.manager.navigation.remove_tool('Back')
+fig.canvas.manager.navigation.remove_tool('Back')
 
 plt.show()

lib/matplotlib/backend_tools.py

@@ -319,9 +319,7 @@ def init_vp(self):
     @classmethod
     def clear(cls, figure):
         """Reset the axes stack"""
-        print('clear')
         if figure in cls.views:
-            print('done clear')
             cls.views[figure].clear()
             cls.positions[figure].clear()
 

lib/matplotlib/backends/backend_gtk3.py

@@ -488,6 +488,8 @@ def _get_navigation(self):
         # must be initialised after toolbar has been setted
         if rcParams['toolbar'] != 'toolbar2':
             navigation = NavigationGTK3(self)
+        else:
+            navigation = None
         return navigation
 
     def get_window_title(self):

lib/matplotlib/backends/backend_tkagg.py

@@ -561,6 +561,8 @@ def _get_navigation(self):
         # must be inited after toolbar is setted
         if rcParams['toolbar'] != 'toolbar2':
             navigation = NavigationTk(self)
+        else:
+            navigation = None
         return navigation
 
     def resize(self, width, height=None):