API: pass a handler to all of the CallbackRegistry instances

tacaswell · tacaswell · commit a3e382caadd4 · 2017-08-21T00:37:10.000-04:00
This handler prints the traceback, rather than letting an exception
raised by the callback propagate.

This is required because not all GUI frameworks gracefully handle
exception raised in mouse/keyboard event callbacks (Qt5 exits the
process on un-handled exceptions).
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -971,7 +971,8 @@ def cla(self):
             spine.cla()
 
         self.ignore_existing_data_limits = True
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         if self._sharex is not None:
             # major and minor are class instances with
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -638,7 +638,8 @@ def __init__(self, axes, pickradius=15):
         self.axes = axes
         self.major = Ticker()
         self.minor = Ticker()
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         self._autolabelpos = True
         self._smart_bounds = False
@@ -739,7 +740,8 @@ def cla(self):
         self.isDefault_label = True
 
         # Clear the callback registry for this axis, or it may "leak"
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         # whether the grids are on
         self._gridOnMajor = (rcParams['axes.grid'] and
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1784,7 +1784,8 @@ def __init__(self, figure):
         figure.set_canvas(self)
         self.figure = figure
         # a dictionary from event name to a dictionary that maps cid->func
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
         self.widgetlock = widgets.LockDraw()
         self._button = None  # the button pressed
         self._key = None  # the key pressed
diff --git a/lib/matplotlib/backend_managers.py b/lib/matplotlib/backend_managers.py
@@ -66,7 +66,8 @@ def __init__(self, figure=None):
         self._tools = {}
         self._keys = {}
         self._toggled = {}
-        self._callbacks = cbook.CallbackRegistry()
+        self._callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         # to process keypress event
         self.keypresslock = widgets.LockDraw()
diff --git a/lib/matplotlib/cm.py b/lib/matplotlib/cm.py
@@ -190,7 +190,8 @@ def __init__(self, norm=None, cmap=None):
             The colormap used to map normalized data values to RGBA colors.
         """
 
-        self.callbacksSM = cbook.CallbackRegistry()
+        self.callbacksSM = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         if cmap is None:
             cmap = get_cmap()
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -319,7 +319,8 @@ def __init__(self,
         # this is used by the property methods in the artist base class
         # which are over-ridden in this class
         del self._axes
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         if figsize is None:
             figsize = rcParams['figure.figsize']
@@ -1231,7 +1232,8 @@ def clf(self, keep_observers=False):
         a gui widget is tracking the axes in the figure.
         """
         self.suppressComposite = None
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         for ax in tuple(self.axes):  # Iterate over the copy.
             ax.cla()
diff --git a/lib/mpl_toolkits/gtktools.py b/lib/mpl_toolkits/gtktools.py
@@ -382,7 +382,8 @@ def __init__(self, r, formatd=None, stringd=None):
             formatd = mlab.get_formatd(r)
 
         self.stringd = stringd
-        self.callbacks = cbook.CallbackRegistry()
+        self.callbacks = cbook.CallbackRegistry(
+            exception_handler=cbook.exception_printer)
 
         self.r = r
 
