Subversion Repositories freemyipod

from ctypes import *

from _ctypes import _SimpleCData

class c_enum(_SimpleCData):

    """

        Resembles the enum datatype from C with an 8 bit size.

        Returns the associated string of a value with c_enum[i]

        Returns the current value of the associated value as c_enum.__repr__()

        Comparison operators work with strings and values at the same time.

        ATTENTION: You can not really see if this is initialized or not.

        If it is uninitialized it will return the first entry of the enum.

        While this may be circumvented by changing the default value to

        something else this will not work if the enum is placed inside a

        ctypes structure as the __init__() method will not be called then.

    """    

    _type_ = c_uint8._type_

    def __init__(self, value = 0):

        if type(value) == str:

            value = getattr(self, value)

        _SimpleCData.__init__(self, value)

        self[value]

    def __getattr__(self, name):

        if name == "value":

            return self.value

        for key, value in enumerate(self._fields_):

            if value == name:

                return key

    def __getitem__(self, lookupkey):

        for key, value in enumerate(self._fields_):

            if key == lookupkey:

                return value

        raise IndexError("Value %d not in range of possible enum values for %s!" % (lookupkey, self.__class__.__name__))

    def __str__(self):

        return self[self.value]

    def __repr__(self):

        return self.__str__()

    def __eq__(self, other):

        if type(other) == str:

            try: return getattr(self, other) == self.value

            except AttributeError: return False

        else:

            return self.value == other

    def __lt__(self, other):

        if type(other) == str:

            try: return self.value < getattr(self, other)

            except AttributeError: return False

        else:

            return self.value < other

    def __gt__(self, other):

        if type(other) == str:

            try: return  self.value > getattr(self, other)

            except AttributeError: return False

        else:

            return self.value > other

    def __le__(self, other):

        if self.value == other or self.value < other:

            return True

        return False

    def __ge__(self, other):

        if self.value == other or self.value > other:

            return True

        return False

    def __ne__(self, other):

        if self.value == other:

            return False

        return True

class ExtendedCStruct(LittleEndianStructure):

    """

        This is a subclass of the LittleEndianStructure.

        It implements functions to easily convert

        structures to/from strings and Bunches.

    """

    def _from_bunch(self, bunch):

        for field, _ in self._fields_:

            if field in bunch:

                setattr(self, field, getattr(bunch, field))

    def _to_bunch(self):

        return Bunch(**{field: getattr(self, field) for field, _ in self._fields_})

    def _from_string(self, string):

        memmove(addressof(self), string, sizeof(self))

    def _to_string(self):

        return string_at(addressof(self), sizeof(self))