A little black magic... When the C++ object (for a window or

whatever) is deleted there is no way to force the Python shadow object
to also be destroyed and clean up all references to it.  This leads to
crashes if the shadow object tries to call a method with the old C++
pointer...  The black magic I've done is to replace the __class__ in the
Python instanc object with a class that raises an exception whenever a
method call is attempted.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15059 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/src/msw/wx.py

@@ -1554,6 +1554,26 @@ def wxPyTypeCast(obj, typeStr):
     return theObj
 
 
+#----------------------------------------------------------------------------
+
+
+class _wxPyDeadObject:
+    """
+    Instances of wx objects that are OOR capable will have their __class__
+    changed to this class when the C++ object is deleted.  This should help
+    prevent crashes due to referencing a bogus C++ pointer.
+    """
+    def __repr__( self ):
+        if not hasattr(self, "_name"):
+            self._name = "[unknown]"
+        return 'wxPython wrapper for deleted %s object!!! Programming logic error' % self._name
+
+    def __getattr__( self, *args ):
+        if not hasattr(self, "_name"):
+            self._name = "[unknown]"
+        raise ValueError, 'Attempt to access attribute of a deleted %s object' % self._name
+
+
 #----------------------------------------------------------------------
 #----------------------------------------------------------------------
 
@@ -1670,10 +1690,10 @@ class wxPyWidgetTester(wxApp):
         self.frame.Show(true)
 
 #----------------------------------------------------------------------------
-# DO NOT hold any other references to this object.  This is how we know when
-# to cleanup system resources that wxWin is holding.  When this module is
-# unloaded, the refcount on __cleanMeUp goes to zero and it calls the
-# wxApp_CleanUp function.
+# DO NOT hold any other references to this object.  This is how we
+# know when to cleanup system resources that wxWin is holding.  When
+# the sys module is unloaded, the refcount on sys.__wxPythonCleanup
+# goes to zero and it calls the wxApp_CleanUp function.
 
 class __wxPyCleanup:
     def __init__(self):