"""

Dict that has a callback on all updates

"""

class UpdateDict(dict):

    updated = None

    updated_args = None

    def _updated(self):

        """

        Assign to new_dict.updated to track updates

        """

        updated = self.updated

        if updated is not None:

            args = self.updated_args

            if args is None:

                args = (self,)

            updated(*args)

    def __setitem__(self, key, item):

        dict.__setitem__(self, key, item)

        self._updated()

    def __delitem__(self, key):

        dict.__delitem__(self, key)

        self._updated()

    def clear(self):

        dict.clear(self)

        self._updated()

    def update(self, *args, **kw):

        dict.update(self, *args, **kw)

        self._updated()

    def setdefault(self, key, failobj=None):

        dict.setdefault(self, key, failobj)

        self._updated()

    def pop(self):

        v = dict.pop(self)

        self._updated()

        return v

    def popitem(self):

        v = dict.popitem(self)

        self._updated()

        return v