Improve error when trying to edit empty figure.

anntzer · anntzer · commit 1a66b6a02cd3 · 2015-07-31T11:08:16.000-07:00
Compare bringing up the axes editor (the green tick button) on a figure with no
axes before and after the patch.
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
@@ -610,6 +610,10 @@ def _init_toolbar(self):
     if figureoptions is not None:
         def edit_parameters(self):
             allaxes = self.canvas.figure.get_axes()
+            if not allaxes:
+                QtWidgets.QMessageBox.warning(
+                    self.parent, "Error", "There are no axes to edit.")
+                return
             if len(allaxes) == 1:
                 axes = allaxes[0]
             else:
