class MyModalDialogHook(wx.ModalDialogHook):
    
        def __init__(self, parent):
        
            wx.ModalDialogHook.__init__(self, parent)
    
    
        def Enter(self, dialog):
        
            # Just for demonstration purposes, intercept all uses of
            # wx.FileDialog. Notice that self doesn't provide any real
            # sandboxing, of course, the program can still read and write
            # files by not using wx.FileDialog to ask the user for their
            # names.
            if isinstance(dialog, wx.FileDialog):
            
                wx.LogError("Access to file system disallowed.")
    
                # Skip showing the file dialog entirely.
                return wx.ID_CANCEL
            
    
            self.lastEnter = wx.DateTime.Now()
    
            # Allow the dialog to be shown as usual.
            return wx.ID_NONE
        
    
        def Exit(self, dialog):
        
            # Again, just for demonstration purposes, show how long did
            # the user take to dismiss the dialog. Notice that we
            # shouldn't use wx.LogMessage() here as self would result in
            # another modal dialog call and hence infinite recursion. In
            # general, the hooks should be as unintrusive as possible.
            wx.LogDebug("%s dialog took %s to be dismissed",
                       dialog.GetClassInfo().GetClassName(),
                       (wx.DateTime.Now() - self.lastEnter).Format())
        
    
    
    if __name__ == '__main__':
    
        app = wx.App(0)
        self.myHook = MyModalDialogHook(None)
        self.myHook.Register()
        app.MainLoop()