Changes to how overridable C++ methods are virtualized for Python.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@37369 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/docs/CHANGES.txt

@@ -25,6 +25,59 @@ wx.EventLoop is now implemented for wxMac.
 Added wxPython wrappers for the new wx.Treebook and wx.Toolbook
 classes. 
 
+Solved a problem that has been around for a very long time in how C++
+methods are virtualized for overriding in derived Python classes.
+Previously we couldn't do it for methods that needed to exist in the
+base class wrappers such that they could be called normally.  (The
+reasons are long and complex, but suffice it to say that it was due to
+mixing C++'s dynamic dispatch, and Python's runtime lookup of the
+method attributes resulting in endless recursion of function calls.)
+Because of this problem I used a hack that I have always hated, and
+that is renaming the base class methods with a "base_" prefix, for
+example wx.Printout.base_OnBeginDocument.  Now that the problem has
+finally been solved I have replaced all the base_Whatever() methods
+with the real Whatever() method as well as a simple wrapper named
+base_Whatever that is marked as deprecated.  So now instead of writing
+your overridden methods like this:
+
+    def OnBeginDocument(self, start, end):
+	# do something here
+	return self.base_OnBeginDocument(start, end)
+
+You can do it the *right way* like this:
+
+    def OnBeginDocument(self, start, end):
+	# do something here
+	return super(MyPrintout, self).OnBeginDocument(start, end)
+
+Note that the old way still works, but you will get a
+DeprecationWarning from calling base_OnBeginDocument.  The classes
+affected by this are:
+
+    * wx.DropSource
+    * wx.DropTarget
+    * wx.TextDropTarget
+    * wx.FileDropTarget
+    * wx.PyLog   (also added the ability to override Flush)
+    * wx.PyApp   (also added the ability to override ExitMainLoop)
+    * wx.Printout
+    * wx.PyPrintPreview
+    * wx.PyPreviewFrame
+    * wx.PreviewControlBar
+    * wx.Process
+    * wx.PyControl
+    * wx.PyPanel
+    * wx.PyScrolledWindow
+    * wx.PyWindow
+    * wx.Timer
+    * wx.grid.PyGridCellRenderer
+    * wx.grid.PyGridCellEditor
+    * wx.grid.PyGridCellAttrProvider
+    * wx.grid.PyGridTableBase
+    * wx.html.HtmlWindow
+    * wx.wizard.PyWizardPage
+
+