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pythonwxpythonpublish-subscribe

Defining a wx.Panel destructor in wxpython

How do you define a destructor for a wx.Panel in wxpython?

META: After inheriting a code base which uses wxpython and PyPubSub I've discovered a huge number of pubsub subscriptions in the __init__ functions of wx.Panel's that are never unsubscribed and cause errors later on in the program.

Solution

  • You should be able to bind to EVT_WINDOW_DESTROY and do the unsub in the handler.

    For example:

    class MyPanel(wx.Panel):

def __init__(self, parent):
    wx.Panel.__init__(self, parent, wx.NewId())

    pub.subscribe(self.__handler, 'event')

    def __destroy(_):
        pub.unsubscribe(self.__handler, 'event')

    self.Bind(wx.EVT_WINDOW_DESTROY, __destroy)

    If above is not working you can protect against the PyDeadObjectError exception, by adding the following in the code where you try to access ExtendedWxPanel:

    if instanceOfExctendedWxPanel: then access it or methods of it.