Application: gvSIG desktop » gvSIG scripting

import operator

from .compat import PY2

from .compat import PY3

from .compat import with_metaclass

from .utils import identity

class _ProxyMethods(object):

    # We use properties to override the values of __module__ and

    # __doc__. If we add these in ObjectProxy, the derived class

    # __dict__ will still be setup to have string variants of these

    # attributes and the rules of descriptors means that they appear to

    # take precedence over the properties in the base class. To avoid

    # that, we copy the properties into the derived class type itself

    # via a meta class. In that way the properties will always take

    # precedence.

    @property

    def __module__(self):

        return self.__wrapped__.__module__

    @__module__.setter

    def __module__(self, value):

        self.__wrapped__.__module__ = value

    @property

    def __doc__(self):

        return self.__wrapped__.__doc__

    @__doc__.setter

    def __doc__(self, value):

        self.__wrapped__.__doc__ = value

    # We similar use a property for __dict__. We need __dict__ to be

    # explicit to ensure that vars() works as expected.

    @property

    def __dict__(self):

        return self.__wrapped__.__dict__

    # Need to also propagate the special __weakref__ attribute for case

    # where decorating classes which will define this. If do not define

    # it and use a function like inspect.getmembers() on a decorator

    # class it will fail. This can't be in the derived classes.

    @property

    def __weakref__(self):

        return self.__wrapped__.__weakref__

class _ProxyMetaType(type):

    def __new__(cls, name, bases, dictionary):

        # Copy our special properties into the class so that they

        # always take precedence over attributes of the same name added

        # during construction of a derived class. This is to save

        # duplicating the implementation for them in all derived classes.

        dictionary.update(vars(_ProxyMethods))

        return type.__new__(cls, name, bases, dictionary)

class Proxy(with_metaclass(_ProxyMetaType)):

    """

    A proxy implementation in pure Python, using slots. You can subclass this to add

    local methods or attributes, or enable __dict__.

    The most important internals:

    * ``__factory__`` is the callback that "materializes" the object we proxy to.

    * ``__target__`` will contain the object we proxy to, once it's "materialized".

    * ``__wrapped__`` is a property that does either:

      * return ``__target__`` if it's set.

      * calls ``__factory__``, saves result to ``__target__`` and returns said result.

    """

    __slots__ = '__target__', '__factory__'

    def __init__(self, factory):

        object.__setattr__(self, '__factory__', factory)

    @property

    def __wrapped__(self, __getattr__=object.__getattribute__, __setattr__=object.__setattr__,

                    __delattr__=object.__delattr__):

        try:

            return __getattr__(self, '__target__')

        except AttributeError:

            try:

                factory = __getattr__(self, '__factory__')

            except AttributeError:

                raise ValueError("Proxy hasn't been initiated: __factory__ is missing.")

            target = factory()

            __setattr__(self, '__target__', target)

            return target

    @__wrapped__.deleter

    def __wrapped__(self, __delattr__=object.__delattr__):

        __delattr__(self, '__target__')

    @__wrapped__.setter

    def __wrapped__(self, target, __setattr__=object.__setattr__):

        __setattr__(self, '__target__', target)

    @property

    def __name__(self):

        return self.__wrapped__.__name__

    @__name__.setter

    def __name__(self, value):

        self.__wrapped__.__name__ = value

    @property

    def __class__(self):

        return self.__wrapped__.__class__

    @__class__.setter

    def __class__(self, value):

        self.__wrapped__.__class__ = value

    @property

    def __annotations__(self):

        return self.__wrapped__.__anotations__

    @__annotations__.setter

    def __annotations__(self, value):

        self.__wrapped__.__annotations__ = value

    def __dir__(self):

        return dir(self.__wrapped__)

    def __str__(self):

        return str(self.__wrapped__)

    if PY3:

        def __bytes__(self):

            return bytes(self.__wrapped__)

    def __repr__(self, __getattr__=object.__getattribute__):

        try:

            target = __getattr__(self, '__target__')

        except AttributeError:

            return '<%s at 0x%x with factory %r>' % (

                type(self).__name__, id(self),

                self.__factory__

            )

        else:

            return '<%s at 0x%x wrapping %r at 0x%x with factory %r>' % (

                type(self).__name__, id(self),

                target, id(target),

                self.__factory__

            )

    def __reversed__(self):

        return reversed(self.__wrapped__)

    if PY3:

        def __round__(self):

            return round(self.__wrapped__)

    def __lt__(self, other):

        return self.__wrapped__ < other

    def __le__(self, other):

        return self.__wrapped__ <= other

    def __eq__(self, other):

        return self.__wrapped__ == other

    def __ne__(self, other):

        return self.__wrapped__ != other

    def __gt__(self, other):

        return self.__wrapped__ > other

    def __ge__(self, other):

        return self.__wrapped__ >= other

    def __hash__(self):

        return hash(self.__wrapped__)

    def __nonzero__(self):

        return bool(self.__wrapped__)

    def __bool__(self):

        return bool(self.__wrapped__)

    def __setattr__(self, name, value, __setattr__=object.__setattr__):

        if hasattr(type(self), name):

            __setattr__(self, name, value)

        else:

            setattr(self.__wrapped__, name, value)

    def __getattr__(self, name):

        if name in ('__wrapped__', '__factory__'):

            raise AttributeError(name)

        else:

            return getattr(self.__wrapped__, name)

    def __delattr__(self, name, __delattr__=object.__delattr__):

        if hasattr(type(self), name):

            __delattr__(self, name)

        else:

            delattr(self.__wrapped__, name)

    def __add__(self, other):

        return self.__wrapped__ + other

    def __sub__(self, other):

        return self.__wrapped__ - other

    def __mul__(self, other):

        return self.__wrapped__ * other

    def __div__(self, other):

        return operator.div(self.__wrapped__, other)

    def __truediv__(self, other):

        return operator.truediv(self.__wrapped__, other)

    def __floordiv__(self, other):

        return self.__wrapped__ // other

    def __mod__(self, other):

        return self.__wrapped__ ^ other

    def __divmod__(self, other):

        return divmod(self.__wrapped__, other)

    def __pow__(self, other, *args):

        return pow(self.__wrapped__, other, *args)

    def __lshift__(self, other):

        return self.__wrapped__ << other

    def __rshift__(self, other):

        return self.__wrapped__ >> other

    def __and__(self, other):

        return self.__wrapped__ & other

    def __xor__(self, other):

        return self.__wrapped__ ^ other

    def __or__(self, other):

        return self.__wrapped__ | other

    def __radd__(self, other):

        return other + self.__wrapped__

    def __rsub__(self, other):

        return other - self.__wrapped__

    def __rmul__(self, other):

        return other * self.__wrapped__

    def __rdiv__(self, other):

        return operator.div(other, self.__wrapped__)

    def __rtruediv__(self, other):

        return operator.truediv(other, self.__wrapped__)

    def __rfloordiv__(self, other):

        return other // self.__wrapped__

    def __rmod__(self, other):

        return other % self.__wrapped__

    def __rdivmod__(self, other):

        return divmod(other, self.__wrapped__)

    def __rpow__(self, other, *args):

        return pow(other, self.__wrapped__, *args)

    def __rlshift__(self, other):

        return other << self.__wrapped__

    def __rrshift__(self, other):

        return other >> self.__wrapped__

    def __rand__(self, other):

        return other & self.__wrapped__

    def __rxor__(self, other):

        return other ^ self.__wrapped__

    def __ror__(self, other):

        return other | self.__wrapped__

    def __iadd__(self, other):

        self.__wrapped__ += other

        return self

    def __isub__(self, other):

        self.__wrapped__ -= other

        return self

    def __imul__(self, other):

        self.__wrapped__ *= other

        return self

    def __idiv__(self, other):

        self.__wrapped__ = operator.idiv(self.__wrapped__, other)

        return self

    def __itruediv__(self, other):

        self.__wrapped__ = operator.itruediv(self.__wrapped__, other)

        return self

    def __ifloordiv__(self, other):

        self.__wrapped__ //= other

        return self

    def __imod__(self, other):

        self.__wrapped__ %= other

        return self

    def __ipow__(self, other):

        self.__wrapped__ **= other

        return self

    def __ilshift__(self, other):

        self.__wrapped__ <<= other

        return self

    def __irshift__(self, other):

        self.__wrapped__ >>= other

        return self

    def __iand__(self, other):

        self.__wrapped__ &= other

        return self

    def __ixor__(self, other):

        self.__wrapped__ ^= other

        return self

    def __ior__(self, other):

        self.__wrapped__ |= other

        return self

    def __neg__(self):

        return -self.__wrapped__

    def __pos__(self):

        return +self.__wrapped__

    def __abs__(self):

        return abs(self.__wrapped__)

    def __invert__(self):

        return ~self.__wrapped__

    def __int__(self):

        return int(self.__wrapped__)

    if PY2:

        def __long__(self):

            return long(self.__wrapped__)  # flake8: noqa

    def __float__(self):

        return float(self.__wrapped__)

    def __oct__(self):

        return oct(self.__wrapped__)

    def __hex__(self):

        return hex(self.__wrapped__)

    def __index__(self):

        return operator.index(self.__wrapped__)

    def __len__(self):

        return len(self.__wrapped__)

    def __contains__(self, value):

        return value in self.__wrapped__

    def __getitem__(self, key):

        return self.__wrapped__[key]

    def __setitem__(self, key, value):

        self.__wrapped__[key] = value

    def __delitem__(self, key):

        del self.__wrapped__[key]

    def __getslice__(self, i, j):

        return self.__wrapped__[i:j]

    def __setslice__(self, i, j, value):

        self.__wrapped__[i:j] = value

    def __delslice__(self, i, j):

        del self.__wrapped__[i:j]

    def __enter__(self):

        return self.__wrapped__.__enter__()

    def __exit__(self, *args, **kwargs):

        return self.__wrapped__.__exit__(*args, **kwargs)

    def __iter__(self):

        return iter(self.__wrapped__)

    def __call__(self, *args, **kwargs):

        return self.__wrapped__(*args, **kwargs)

    def __reduce__(self):

        return identity, (self.__wrapped__,)

    def __reduce_ex__(self, protocol):

        return identity, (self.__wrapped__,)