tlinnet/objc_util.py

## objc_util.py
# coding: utf-8

__all__ = ['c', 'LP64', 'CGFloat', 'NSInteger', 'NSUInteger', 'NSNotFound', 'NSUTF8StringEncoding', 'NS_UTF8', 'CGPoint', 'CGSize', 'CGVector', 'CGRect', 'CGAffineTransform', 'UIEdgeInsets', 'NSRange', 'sel', 'ObjCClass', 'ObjCInstance', 'ObjCClassMethod', 'ObjCInstanceMethod', 'NSObject', 'NSArray', 'NSMutableArray', 'NSDictionary', 'NSMutableDictionary', 'NSSet', 'NSMutableSet', 'NSString', 'NSMutableString', 'NSData', 'NSMutableData', 'NSNumber', 'NSURL', 'NSEnumerator', 'NSThread', 'NSBundle', 'UIColor', 'UIImage', 'UIBezierPath', 'UIApplication', 'UIView', 'ObjCBlock', 'ns', 'nsurl', 'retain_global', 'release_global', 'on_main_thread', 'create_objc_class',
'Structure', 'sizeof', 'byref', 'c_void_p', 'c_char', 'c_byte', 'c_char_p', 'c_double', 'c_float', 'c_int', 'c_longlong', 'c_short', 'c_bool', 'c_long', 'c_int32', 'c_ubyte', 'c_uint', 'c_ushort', 'c_ulong', 'c_ulonglong', 'POINTER', 'pointer', 'load_framework', 'nsdata_to_bytes', 'uiimage_to_png']

try:
	import ctypes
except ImportError:
	raise NotImplementedError("objc_util requires ctypes, which doesn't seem to be available.")

from ctypes import Structure, sizeof, byref, cdll, pydll, c_void_p, c_char, c_byte, c_char_p, c_double, c_float, c_int, c_longlong, c_short, c_bool, c_long, c_int32, c_ubyte, c_uint, c_ushort, c_ulong, c_ulonglong, POINTER, pointer
import re
import sys
import os
import itertools
import ui
import weakref
import string
import pyparsing as pp
import inspect
import functools

PY3 = sys.version_info[0] >= 3

if PY3:
	basestring = str
	string_lowercase = string.ascii_lowercase
	xrange = range
	long = int
else:
	bytes = str
	string_lowercase = string.lowercase

def filter_list(*args, **kwargs):
	if PY3:
		return list(filter(*args, **kwargs))
	return filter(*args, **kwargs)

LP64 = (sizeof(c_void_p) == 8)

_retained_globals = []
_cached_classes = {}
_cached_instances = weakref.WeakValueDictionary()
_tracefunc = None

c = cdll.LoadLibrary(None)

class_getName = c.class_getName
class_getName.restype = c_char_p
class_getName.argtypes = [c_void_p]

class_getSuperclass = c.class_getSuperclass
class_getSuperclass.restype = c_void_p
class_getSuperclass.argtypes = [c_void_p]

class_addMethod = c.class_addMethod
class_addMethod.restype = c_bool
class_addMethod.argtypes = [c_void_p, c_void_p, c_void_p, c_char_p]

class_getInstanceMethod = c.class_getInstanceMethod
class_getInstanceMethod.restype = c_void_p
class_getInstanceMethod.argtypes = [c_void_p, c_void_p]

class_getClassMethod = c.class_getClassMethod
class_getClassMethod.restype = c_void_p
class_getClassMethod.argtypes = [c_void_p, c_void_p]

objc_allocateClassPair = c.objc_allocateClassPair
objc_allocateClassPair.restype = c_void_p
objc_allocateClassPair.argtypes = [c_void_p, c_char_p, c_int]

objc_registerClassPair = c.objc_registerClassPair
objc_registerClassPair.restype = None
objc_registerClassPair.argtypes = [c_void_p]

objc_getClass = c.objc_getClass
objc_getClass.argtypes = [c_char_p]
objc_getClass.restype = c_void_p

objc_getClassList = c.objc_getClassList
objc_getClassList.restype = c_int
objc_getClassList.argtypes = [c_void_p, c_int]

method_getTypeEncoding = c.method_getTypeEncoding
method_getTypeEncoding.argtypes = [c_void_p]
method_getTypeEncoding.restype = c_char_p

sel_getName = c.sel_getName
sel_getName.restype = c_char_p
sel_getName.argtypes = [c_void_p]

sel_registerName = c.sel_registerName
sel_registerName.restype = c_void_p
sel_registerName.argtypes = [c_char_p]

object_getClass = c.object_getClass
object_getClass.argtypes = [c_void_p]
object_getClass.restype = c_void_p

class_copyMethodList = c.class_copyMethodList
class_copyMethodList.restype = ctypes.POINTER(c_void_p)
class_copyMethodList.argtypes = [c_void_p, ctypes.POINTER(ctypes.c_uint)]

class_getProperty = c.class_getProperty
class_getProperty.restype = c_void_p
class_getProperty.argtypes = [c_void_p, c_char_p]

property_getAttributes = c.property_getAttributes
property_getAttributes.argtypes = [c_void_p]
property_getAttributes.restype = c_char_p

method_getName = c.method_getName
method_getName.restype = c_void_p
method_getName.argtypes = [c_void_p]

class objc_method_description (Structure):
	_fields_ = [('sel', c_void_p), ('types', c_char_p)]

objc_getProtocol = c.objc_getProtocol
objc_getProtocol.restype = c_void_p
objc_getProtocol.argtypes = [c_char_p]

protocol_getMethodDescription = c.protocol_getMethodDescription
protocol_getMethodDescription.restype = objc_method_description
protocol_getMethodDescription.argtypes = [c_void_p, c_void_p, c_bool, c_bool]

objc_msgSend = c.objc_msgSend
if not LP64:
	objc_msgSend_stret = c.objc_msgSend_stret

free = c.free
free.argtypes = [c_void_p]
free.restype = None

CGFloat = c_double if LP64 else c_float
NSInteger = c_long if LP64 else c_int
NSUInteger = c_ulong if LP64 else c_uint

if PY3:
	NSNotFound = sys.maxsize
else:
	NSNotFound = sys.maxint

NSUTF8StringEncoding = 4
NS_UTF8 = NSUTF8StringEncoding

class CGPoint (Structure):
	_fields_ = [('x', CGFloat), ('y', CGFloat)]

class CGSize (Structure):
	_fields_ = [('width', CGFloat), ('height', CGFloat)]

class CGVector (Structure):
	_fields_ = [('dx', CGFloat), ('dy', CGFloat)]

class CGRect (Structure):
	_fields_ = [('origin', CGPoint), ('size', CGSize)]

class CGAffineTransform (Structure):
	_fields_ = [('a', CGFloat), ('b', CGFloat), ('c', CGFloat), ('d', CGFloat), ('tx', CGFloat), ('ty', CGFloat)]

class UIEdgeInsets (Structure):
	_fields_ = [('top', CGFloat), ('left', CGFloat), ('bottom', CGFloat), ('right', CGFloat)]

class NSRange (Structure):
	_fields_ = [('location', NSUInteger), ('length', NSUInteger)]

# c.f. https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html
type_encodings = {'c': c_byte, 'i': c_int, 's': c_short, 'l': c_int32, 'q': c_longlong,
	'C': c_ubyte, 'I': c_uint, 'S': c_ushort, 'L': c_ulong, 'Q': c_ulonglong,
	'f': c_float, 'd': c_double, 'B': c_bool, 'v': None, '*': c_char_p,
	'@': c_void_p, '#': c_void_p, ':': c_void_p,
	'{CGPoint}': CGPoint, '{CGSize}': CGSize, '{CGRect}': CGRect, '{CGVector}': CGVector,
	'{CGAffineTransform}': CGAffineTransform, '{UIEdgeInsets}': UIEdgeInsets, '{_NSRange}': NSRange,
	'?': c_void_p, '@?': c_void_p
}

def split_encoding(encoding):
	# This function is mostly copied from pybee's rubicon.objc
	# (https://github.com/pybee/rubicon-objc)
	# License: https://github.com/pybee/rubicon-objc/blob/master/LICENSE
	type_encodings = []
	braces, brackets = 0, 0
	typecode = ''
	if PY3 and isinstance(encoding, bytes):
		encoding = encoding.decode('ascii')
	for c in encoding:
		if c == '{':
			if typecode and typecode[-1:] != '^' and braces == 0 and brackets == 0:
				type_encodings.append(typecode)
				typecode = ''
			typecode += c
			braces += 1
		elif c == '}':
			typecode += c
			braces -= 1
		elif c == '[':
			if typecode and typecode[-1:] != '^' and braces == 0 and brackets == 0:
				type_encodings.append(typecode)
				typecode = ''
			typecode += c
			brackets += 1
		elif c == ']':
			typecode += c
			brackets -= 1
		elif braces or brackets:
			typecode += c
		elif c in string.digits:
			pass
		elif c in 'rnNoORV':
			pass
		elif c in '^cislqCISLQfdBv*@#:b?':
			if c == '?' and typecode[-1:] == '@':
				typecode += c
			elif typecode and typecode[-1:] == '^':
				typecode += c
			else:
				if typecode:
					type_encodings.append(typecode)
				typecode = c
	if typecode:
		type_encodings.append(typecode)
	return type_encodings


def struct_from_tuple(cls, t):
	args = []
	for i, field_value in enumerate(t):
		if isinstance(field_value, tuple):
			args.append(struct_from_tuple(cls._fields_[i][1], field_value))
		else:
			args.append(field_value)
	return cls(*args)

def _struct_class_from_fields(fields):
	class AnonymousStructure (Structure):
		from_tuple = classmethod(struct_from_tuple)
	struct_fields = []
	for i, field in enumerate(fields):
		if isinstance(field, tuple):
			struct_fields.append(field)
		else:
			struct_fields.append((string_lowercase[i], _struct_class_from_fields(field)))
			i += 1
	AnonymousStructure._fields_ = struct_fields
	return AnonymousStructure

def _list_to_fields(result):
	fields = []
	i = 0
	if isinstance(result, basestring):
		for char in split_encoding(result):
			c_type = parse_types(char)[0]
			fields.append((string_lowercase[i], c_type))
			i += 1
	else:
		if len(result) == 1:
			return _list_to_fields(result[0])
		for r in result:
			fields.append(_list_to_fields(r))
	return fields

def _result_to_list(result):
	struct_result = []
	for member in result:
		if isinstance(member, basestring):
			struct_result.append(member)
		else:
			struct_result.append(_result_to_list([member[2]]))
	return struct_result

_enclosed = pp.Forward()
_nested_curlies = pp.nestedExpr('{', '}', content=_enclosed)
_enclosed << (pp.Word(pp.alphas + '?_' + pp.nums) | '=' | _nested_curlies)

def parse_struct(encoding):
	comps = _enclosed.parseString(encoding).asList()[0]
	struct_name = comps[0]
	struct_members = comps[2:]
	fields = _list_to_fields(_result_to_list(struct_members))
	struct_class = _struct_class_from_fields(fields)
	struct_class.__name__ = (struct_name + '_Structure').replace('?', '_')
	return struct_class

_cached_parse_types_results = {}

def parse_types(type_encoding):
	'''Take an Objective-C type encoding string and convert it to a tuple of (restype, argtypes) appropriate for objc_msgSend()'''
	cached_result = _cached_parse_types_results.get(type_encoding)
	if cached_result:
		return cached_result
	def get_type_for_code(enc_str):
		if enc_str.startswith('{'):
			struct_name = enc_str[0:enc_str.find('=')] + '}'
			if struct_name in type_encodings:
				return type_encodings[struct_name]
			else:
				return parse_struct(enc_str)
		if enc_str[0] in 'rnNoORV': #const, in, inout... don't care about these
			enc_str = enc_str[1:]
		if enc_str[0] == '^':
			if re.match(r'\^\{\w+=#?\}', enc_str):
				return c_void_p # pointer to opaque type, e.g. CGPathRef, CGImageRef...
			else:
				return POINTER(get_type_for_code(enc_str[1:]))
		if enc_str[0] == '[': #array
			return c_void_p
		try:
			t = type_encodings[enc_str]
			return t
		except KeyError:
			raise NotImplementedError('Unsupported type encoding (%s)' % (enc_str,))
	encoded_types = filter_list(lambda x: bool(x), split_encoding(type_encoding))
	encoded_argtypes = encoded_types[3:]
	argtypes = [get_type_for_code(x) for x in encoded_argtypes]
	restype = get_type_for_code(encoded_types[0])
	cached_result = (restype, [c_void_p, c_void_p] + argtypes, encoded_argtypes)
	_cached_parse_types_results[type_encoding] = cached_result
	return cached_result

def sel(sel_name):
	'''Convenience function to convert a string to a selector'''
	if PY3 and isinstance(sel_name, str):
		sel_name = sel_name.encode('ascii')
	return sel_registerName(sel_name)

def _first_letter_cap(s):
	if not s:
		return ''
	return s[0].upper() + s[1:]

def get_possible_method_names(name, args, kwargs):
	# Return a list of possible ObjC method names for a given combination of arguments. Basically all permutations of keyword args...
	if '_' in name:
		# Should never actually happen...
		return [(name, [])]
	if name.endswith('With'):
		name = name[:-4]
	possible_names = []
	if len(args) == 0 and len(kwargs) == 0:
		possible_names.append((name, []))
	elif len(kwargs) == 0 and len(args) == 1:
		possible_names.append((name + '_', []))
	else:
		permutations = itertools.permutations(kwargs.keys())
		found_methods = []
		for perm in permutations:
			name1 = name + '_' + '_'.join(perm) + '_'
			possible_names.append((name1, list(perm)))
			if len(args) == 0:
				name2 = name + 'With%s_' % (_first_letter_cap(perm[0]),) + '_'.join(perm[1:])
				if len(perm) > 1:
					name2 += '_'
				possible_names.append((name2, list(perm)))
				name3 = name + _first_letter_cap(perm[0]) + '_' + '_'.join(perm[1:])
				if len(perm) > 1:
					name3 += '_'
				possible_names.append((name3, list(perm)))

	return possible_names

def resolve_cls_method(cls, name, args, kwargs):
	# Return (method_name, ordered_kwargs), or raise an AttributeError if either no method could be found, or if the mapping was ambiguous.
	kwargs_copy = dict(kwargs)
	if 'argtypes' in kwargs_copy:
		del kwargs_copy['argtypes']
	if 'restype' in kwargs_copy:
		del kwargs_copy['restype']
	possible_names = get_possible_method_names(name, args, kwargs_copy)
	valid_names = []
	for method_name, kwarg_order in possible_names:
		try:
			meth = ObjCClassMethod(cls, method_name)
			valid_names.append((method_name, kwarg_order))
		except AttributeError:
			pass
	if len(valid_names) == 1:
		return valid_names[0]
	elif len(valid_names) == 0:
		raise AttributeError('No method found for %s' % (name,))
	else:
		raise AttributeError('Method name is ambiguous')

def resolve_instance_method(obj, name, args, kwargs):
	# Return (method_name, ordered_kwargs), or raise an AttributeError if either no method could be found, or if the mapping was ambiguous.
	kwargs_copy = dict(kwargs)
	if 'argtypes' in kwargs_copy:
		del kwargs_copy['argtypes']
	if 'restype' in kwargs_copy:
		del kwargs_copy['restype']
	possible_names = get_possible_method_names(name, args, kwargs_copy)
	valid_names = []
	for method_name, kwarg_order in possible_names:
		try:
			possibly_property = len(args) == 0 and len(kwargs) == 0
			meth = ObjCInstanceMethod(obj, method_name, allow_property=possibly_property)
			valid_names.append((method_name, kwarg_order))
		except AttributeError:
			pass
	if len(valid_names) == 1:
		return valid_names[0]
	elif len(valid_names) == 0:
		raise AttributeError('No method found for %s' % (name,))
	else:
		raise AttributeError('Method name is ambiguous')

class ObjCClass (object):
	'''Wrapper for a pointer to an Objective-C class; acts as a proxy for calling Objective-C class methods. Method calls are converted to Objective-C messages on-the-fly -- this is done by replacing underscores in the method name with colons in the selector name, and using the selector and arguments for a call to the low-level objc_msgSend function in the Objective-C runtime. For example, calling `NSDictionary.dictionaryWithObject_forKey_(obj, key)` (Python) is translated to `[NSDictionary dictionaryWithObject:obj forKey:key]` (Objective-C). If a method call returns an Objective-C object, it is wrapped in an ObjCInstance, so calls can be chained (ObjCInstance uses an equivalent proxy mechanism).'''
	def __new__(cls, name):
		if PY3 and isinstance(name, str):
			name = name.encode('ascii')

		# Memoize classes by name (get identical object every time):
		cached_class = _cached_classes.get(name)
		if cached_class:
			return cached_class
		cached_class = super(ObjCClass, cls).__new__(cls)
		_cached_classes[name] = cached_class
		return cached_class

	def __init__(self, name):
		if PY3 and isinstance(name, str):
			name = name.encode('ascii')

		self.ptr = objc_getClass(name)
		if self.ptr is None:
			raise ValueError('no Objective-C class named \'%s\' found' % (name,))
		self._as_parameter_ = self.ptr
		self.class_name = name
		self._cached_methods = {}

	def __str__(self):
		return '<ObjCClass: %s>' % (self.class_name,)

	def __eq__(self, other):
		return isinstance(other, ObjCClass) and self.class_name == other.class_name

	def __getattr__(self, attr):
		cached_method = self._cached_methods.get(attr, None)
		if not cached_method:
			if '_' in attr:
				# Old method call syntax
				cached_method = ObjCClassMethod(self, attr)
			else:
				# New syntax, actual method resolution is done at call time
				cached_method = ObjCClassMethodProxy(self, attr)
			self._cached_methods[attr] = cached_method
		return cached_method

	def __dir__(self):
		objc_class_ptr = object_getClass(self.ptr)
		py_methods = []
		while objc_class_ptr is not None:
			num_methods = c_uint(0)
			method_list_ptr = class_copyMethodList(objc_class_ptr, byref(num_methods))
			for i in xrange(num_methods.value):
				selector = method_getName(method_list_ptr[i])
				sel_name = sel_getName(selector)
				if PY3:
					sel_name = sel_name.decode('ascii')
				py_method_name = sel_name.replace(':', '_')
				if '.' not in py_method_name:
					py_methods.append(py_method_name)
			free(method_list_ptr)
			# Walk up the class hierarchy to add methods from superclasses:
			objc_class_ptr = class_getSuperclass(objc_class_ptr)
			if objc_class_ptr == object_getClass(NSObject):
				# Don't list all methods from NSObject (too much cruft from categories)
				py_methods += NSObject_class_methods
				break
		py_methods = sorted(set(py_methods))
		return py_methods

	@classmethod
	def get_names(cls, prefix=None):
		num_classes = objc_getClassList(None, 0)
		buffer = (c_void_p * num_classes)()
		objc_getClassList(buffer, num_classes)
		class_names = []
		for i in xrange(num_classes):
			n = class_getName(buffer[i])
			if PY3:
				n = n.decode('ascii')
			class_names.append(n)
		filtered_list = class_names if prefix is None else filter_list(lambda x: x.startswith(prefix), class_names)
		return sorted(filtered_list)

	@classmethod
	def create(cls, *args, **kwargs):
		return create_objc_class(*args, **kwargs)


class ObjCIterator (object):
	'''Wrapper for an NSEnumerator object -- this is used for supporting `for ... in` iteration for Objective-C collection types (NSArray, NSDictionary, NSSet).'''
	def __init__(self, obj):
		self.enumerator = obj.objectEnumerator()

	def __iter__(self):
		return self

	def next(self):
		next_obj = self.enumerator.nextObject()
		if next_obj is None:
			raise StopIteration()
		return next_obj

	def __next__(self):
		return self.next()

class ObjCInstance (object):
	'''Wrapper for a pointer to an Objective-C instance; acts as a proxy for sending messages to the object. Method calls are converted to Objective-C messages on-the-fly -- this is done by replacing underscores in the method name with colons in the selector name, and using the selector and arguments for a call to the low-level objc_msgSend function in the Objective-C runtime. For example, calling `obj.setFoo_withBar_(foo, bar)` (Python) is translated to `[obj setFoo:foo withBar:bar]` (Objective-C). If a method call returns an Objective-C object, it is also wrapped in an ObjCInstance, so calls can be chained.'''

	def __new__(cls, ptr):
		# If there is already an instance that wraps this pointer, return the same object...
		# This makes it a little easier to put auxiliary data into the instance (e.g. to use in an ObjC callback)
		# Note however that a new instance may be created for the same underlying ObjC object if the last instance gets garbage-collected.
		if isinstance(ptr, ObjCInstance):
			return ptr
		if hasattr(ptr, '_objc_ptr'):
			ptr = ptr._objc_ptr
		if isinstance(ptr, c_void_p):
			ptr = ptr.value
		cached_instance = _cached_instances.get(ptr)
		if cached_instance is not None:
			return cached_instance
		objc_instance = super(ObjCInstance, cls).__new__(cls)
		_cached_instances[ptr] = objc_instance
		objc_instance.ptr = ptr
		objc_instance._as_parameter_ = ptr
		objc_instance._cached_methods = {}
		objc_instance.weakrefs = weakref.WeakValueDictionary()
		if ptr:
			# Retain the ObjC object, so it doesn't get freed while a pointer to it exists:
			objc_instance.retain(restype=c_void_p, argtypes=[])
		return objc_instance

	def __str__(self):
		objc_msgSend = c['objc_msgSend']
		objc_msgSend.argtypes = [c_void_p, c_void_p]
		objc_msgSend.restype = c_void_p
		desc = objc_msgSend(self.ptr, sel('description'))
		objc_msgSend.argtypes = [c_void_p, c_void_p]
		objc_msgSend.restype = c_char_p
		desc_str = objc_msgSend(desc, sel('UTF8String'))
		if PY3:
			return desc_str.decode('utf-8')
		return desc_str

	def _get_objc_classname(self):
		return class_getName(object_getClass(self.ptr))

	def __repr__(self):
		return '<%s: %s>' % (self._get_objc_classname(), str(self))

	def __eq__(self, other):
		return isinstance(other, ObjCInstance) and self.ptr == other.ptr

	def __hash__(self):
		return hash(self.ptr)

	def __iter__(self):
		if any(self.isKindOfClass_(c) for c in (NSArray, NSDictionary, NSSet)):
			return ObjCIterator(self)
		raise TypeError('%s is not iterable' % (self._get_objc_classname(),))

	def __nonzero__(self):
		try:
			return len(self) != 0
		except TypeError:
			return self.ptr != None

	def __bool__(self):
		return self.__nonzero__()

	def __len__(self):
		if any(self.isKindOfClass_(c) for c in (NSArray, NSDictionary, NSSet)):
			return self.count()
		raise TypeError('object of type \'%s\' has no len()' % (self._get_objc_classname(),))

	def __getitem__(self, key):
		if self.isKindOfClass_(NSArray):
			if not isinstance(key, (int, long)):
				raise TypeError('array indices must be integers not %s' % (type(key),))
			array_length = self.count()
			if key < 0:
				# a[-1] is equivalent to a[len(a) - 1]
				key = array_length + key
			if key < 0 or key >= array_length:
				raise IndexError('array index out of range')
			return self.objectAtIndex_(key)
		elif self.isKindOfClass_(NSDictionary):
			# allow to use Python strings as keys, convert to NSString implicitly:
			ns_key = ns(key)
			# NOTE: Unlike Python dicts, NSDictionary returns nil (None) for keys that don't exist.
			return self.objectForKey_(ns_key)
		raise TypeError('%s does not support __getitem__' % (self._get_objc_classname(),))

	def __delitem__(self, key):
		if self.isKindOfClass_(NSMutableArray):
			if not isinstance(key, (int, long)):
				raise TypeError('array indices must be integers not %s' % (type(key),))
			array_length = self.count()
			if key < 0:
				# a[-1] is equivalent to a[len(a) - 1]
				key = array_length + key
			if key < 0 or key >= array_length:
				raise IndexError('array index out of range')
			self.removeObjectAtIndex_(key)
		elif self.isKindOfClass_(NSMutableDictionary):
			ns_key = ns(key)
			return self.removeObjectForKey_(ns_key)
		else:
			raise TypeError('%s does not support __delitem__' % (self._get_objc_classname(),))

	def __setitem__(self, key, value):
		if self.isKindOfClass_(NSMutableArray):
			if not isinstance(key, (int, long)):
				raise TypeError('array indices must be integers not %s' % (type(key),))
			array_length = self.count()
			if key < 0:
				# a[-1] is equivalent to a[len(a) - 1]
				key = array_length + key
			if key < 0 or key >= array_length:
				raise IndexError('array index out of range')
			self.replaceObjectAtIndex_withObject_(key, ns(value))
		elif self.isKindOfClass_(NSMutableDictionary):
			self.setObject_forKey_(ns(value), ns(key))
		else:
			raise TypeError('%s does not support __setitem__' % (self._get_objc_classname(),))

	def __getattr__(self, attr):
		cached_method = self._cached_methods.get(attr, None)
		if not cached_method:
			if '_' in attr:
				# Old method call syntax
				cached_method = ObjCInstanceMethod(self, attr)
			else:
				# New syntax, actual method resolution is done at call time
				cached_method = ObjCInstanceMethodProxy(self, attr)
			self._cached_methods[attr] = cached_method
		return cached_method

	def __setattr__(self, name, value):
		if name in ('ptr', 'weakrefs', '_cached_methods', '_as_parameter_'):
			self.__dict__[name] = value
			return
		try:
			setter_method = getattr(self, 'set%s%s_' % (name[0].upper(), name[1:]))
			setter_method(value)
		except AttributeError:
			self.__dict__[name] = value

	def __dir__(self):
		objc_class_ptr = object_getClass(self.ptr)
		py_methods = []
		while objc_class_ptr is not None:
			num_methods = c_uint(0)
			method_list_ptr = class_copyMethodList(objc_class_ptr, byref(num_methods))
			for i in xrange(num_methods.value):
				selector = method_getName(method_list_ptr[i])
				sel_name = sel_getName(selector)
				if PY3:
					sel_name = sel_name.decode('ascii')
				py_method_name = sel_name.replace(':', '_')
				if '.' not in py_method_name:
					py_methods.append(py_method_name)
			free(method_list_ptr)
			# Walk up the class hierarchy to add methods from superclasses:
			objc_class_ptr = class_getSuperclass(objc_class_ptr)
			if objc_class_ptr == NSObject.ptr:
				# Don't list all NSObject methods (too much cruft from categories...)
				py_methods += NSObject_instance_methods
				break
		return sorted(set(py_methods))

	def __del__(self):
		# Release the ObjC object's memory:
		objc_msgSend = c['objc_msgSend']
		objc_msgSend.argtypes = [c_void_p, c_void_p]
		objc_msgSend.restype = None
		objc_msgSend(self.ptr, sel('release'))
		#self.release(restype=None, argtypes=[])

def _get_possible_selector_names(method_name):
	# Generate all possible selector names from a Python method name. For most methods, this isn't necessary,
	# and the selector is generated simply by replacing underscores with colons, but in case the selector also
	# contains underscores, the mapping is ambiguous, so all permutations of colons and underscores need to be checked.
	izip_longest = itertools.zip_longest if PY3 else itertools.izip_longest
	return [''.join([x+y for x, y in izip_longest(method_name.split('_'), s, fillvalue='')]) for s in [''.join(x) for x in itertools.product(':_', repeat=len(method_name.split('_'))-1)]]

def _auto_wrap(arg, typecode, argtype):
	'''Helper function for `ObjCInstance/ClassMethod.__call__`'''
	if typecode == '@' or typecode.startswith('^{'):
		return ns(arg)
	elif typecode == ':' and isinstance(arg, basestring):
		# if a selector is expected, also allow a string:
		return sel(arg)
	elif issubclass(argtype, Structure) and isinstance(arg, tuple):
		# Automatically convert tuples to structs
		return struct_from_tuple(argtype, arg)
	return arg


class ObjCClassMethodProxy (object):
	'''A proxy for an ObjCClassMethod that is resolved to an actual method when calling it. A proxy may represent different methods, depending on the keyword arguments that are passed (and used to construct an ObjC selector from the call).'''
	def __init__(self, cls, name):
		self.cls = weakref.ref(cls)
		self.name = name
		# Determining the method for a given combination of args/kwargs can be expensive, so it's cached by 'num_args/sorted_kwarg_keys'. The cache contains a pair of (ObjCClassMethod, ordered_kwarg_keys).
		self.method_cache = {}

	def __call__(self, *args, **kwargs):
		cls = self.cls()
		if cls is None:
			# If the class doesn't exist anymore, don't do anything
			# (this is unlikely to happen in practice)
			return
		cache_key = '%i/' % (len(args),) + ','.join(sorted(kwargs.keys()))
		cached = self.method_cache.get(cache_key)
		if cached:
			method, kwarg_order = cached
		else:
			method_name, kwarg_order = resolve_cls_method(cls, self.name, args, kwargs)
			method = ObjCClassMethod(cls, method_name)
			self.method_cache[cache_key] = (method, kwarg_order)
		ordered_args = list(args) + [kwargs[key] for key in kwarg_order]
		# Pass through restype and argtypes keyword args:
		kw = {k: kwargs[k] for k in ('restype', 'kwargs') if k in kwargs}
		return method(*ordered_args, **kw)


class ObjCClassMethod (object):
	'''Wrapper for an Objective-C class method. ObjCClass generates these objects automatically when accessing an attribute, you typically don't need use this class directly.'''
	def __init__(self, cls, method_name):
		self.cls = cls
		self.sel_name = method_name.replace('_', ':')
		method = class_getClassMethod(cls.ptr, sel(self.sel_name))
		if not method:
			# Couldn't find a method, try all combinations of underscores and colons...
			# For selectors that contain underscores, the mapping from Python method name to selector name is ambiguous.
			possible_selector_names = _get_possible_selector_names(method_name)
			for possible_sel_name in possible_selector_names:
				method = class_getClassMethod(cls.ptr, sel(possible_sel_name))
				if method:
					self.sel_name = possible_sel_name
					break
		if method:
			self.method = method
			self.encoding = method_getTypeEncoding(method)
		else:
			raise AttributeError('No class method found for selector "%s"' % (self.sel_name))

	def __call__(self, *args, **kwargs):
		cls = self.cls
		if cls is None:
			return
		type_encoding = self.encoding
		try:
			argtypes = kwargs['argtypes']
			restype = kwargs['restype']
			argtypes = [c_void_p, c_void_p] + argtypes
		except KeyError:
			restype, argtypes, argtype_encodings = parse_types(type_encoding)
			if len(args) != len(argtypes) - 2:
				raise TypeError('expected %i arguments, got %i' % (len(argtypes) - 2, len(args)))
			# Automatically convert Python strings to NSString etc. for object arguments
			# (this is a no-op for arguments that are already `ObjCInstance` objects):
			args = tuple(_auto_wrap(a, argtype_encodings[i], argtypes[i+2]) for i, a in enumerate(args))
		objc_msgSend = c['objc_msgSend']
		objc_msgSend.argtypes = argtypes
		objc_msgSend.restype = restype
		res = objc_msgSend(cls, sel(self.sel_name), *args)
		return_type_enc = chr(type_encoding[0]) if PY3 else type_encoding[0]
		if res and return_type_enc == '@':
			return ObjCInstance(res)
		return res

class ObjCInstanceMethodProxy (object):
	'''A proxy for an ObjCInstanceMethod that is resolved to an actual method when calling it. A proxy may represent different methods, depending on the keyword arguments that are passed (and used to construct an ObjC selector from the call).'''
	def __init__(self, obj, name):
		self.obj = weakref.ref(obj)
		self.name = name
		# Determining the method for a given combination of args/kwargs can be expensive, so it's cached by 'num_args/sorted_kwarg_keys'. The cache contains a pair of (ObjCClassMethod, ordered_kwarg_keys).
		self.method_cache = {}

	def __call__(self, *args, **kwargs):
		obj = self.obj()
		if obj is None:
			# If the instance doesn't exist anymore, don't do anything
			# (this is unlikely to happen in practice)
			return
		cache_key = '%i/' % (len(args),) + ','.join(sorted(kwargs.keys()))
		cached = self.method_cache.get(cache_key)
		if cached:
			method, kwarg_order = cached
		else:
			method_name, kwarg_order = resolve_instance_method(obj, self.name, args, kwargs)
			method = ObjCInstanceMethod(obj, method_name)
			self.method_cache[cache_key] = (method, kwarg_order)
		ordered_args = list(args) + [kwargs[key] for key in kwarg_order]
		# Pass through restype and argtypes keyword args:
		kw = {k: kwargs[k] for k in ('restype', 'kwargs') if k in kwargs}
		return method(*ordered_args, **kw)


class ObjCInstanceMethod (object):
	'''Wrapper for an Objective-C instance method. ObjCInstance generates these objects automatically when accessing an attribute, you typically don't need to use this class directly.'''
	def __init__(self, obj, method_name, allow_property=True):
		self.obj = obj
		objc_class = object_getClass(obj.ptr)
		self.encoding = None
		method = None
		self.sel_name = method_name.replace('_', ':')
		method = class_getInstanceMethod(objc_class, sel(self.sel_name))
		self._objc_msgSend = None
		if not method and '_' in method_name:
			# Couldn't find a method, try all combinations of underscores and colons...
			# For selectors that contain underscores, the mapping from Python method name to selector name is ambiguous.
			possible_selector_names = _get_possible_selector_names(method_name)
			for possible_sel_name in possible_selector_names:
				method = class_getInstanceMethod(objc_class, sel(possible_sel_name))
				if method:
					self.sel_name = possible_sel_name
					break
		if allow_property and not method and ((method_name.startswith('set') and self.sel_name.endswith(':')) or self.sel_name.find(':') == -1):
			#Looks like it could be a property
			prop_name = method_name
			if method_name.startswith('set'):
				prop_name = method_name[3].lower() + method_name[4:-1]
			else:
				prop_name = method_name
			if PY3 and isinstance(prop_name, str):
				prop_name = prop_name.encode('ascii')
			prop = class_getProperty(objc_class, prop_name)
			if prop:
				#TODO: Check if the property is read-only when a setter is used...
				prop_attrs = property_getAttributes(prop)
				if PY3:
					prop_attrs = prop_attrs.decode('ascii')
				prop_type_encoding = re.search('T(.+?),', prop_attrs).group(1)
				if method_name.startswith('set'):
					#NOTE: The offsets/sizes are obviously incorrect... (should still work though)
					self.encoding = 'v0@0:0' + prop_type_encoding + '0'
					if PY3:
						self.encoding = self.encoding.encode('ascii')
					sel_name_match = re.search(r'S(.*?)(:?,.*?|$)', prop_attrs)
					if sel_name_match:
						self.sel_name = sel_name_match.group(1)
				else:
					self.encoding = prop_type_encoding + '0@0:0'
					if PY3:
						self.encoding = self.encoding.encode('ascii')
					sel_name_match = re.search(r'G(.*?)(:?,.*?|$)', prop_attrs)
					if sel_name_match:
						self.sel_name = sel_name_match.group(1)
		if not self.encoding and method:
			self.method = method
			self.encoding = method_getTypeEncoding(method)
		elif not self.encoding:
			raise AttributeError('No method found for selector "%s"' % (self.sel_name))

	def __call__(self, *args, **kwargs):
		obj = self.obj
		if obj is None:
			return
		type_encoding = self.encoding
		try:
			argtypes = kwargs['argtypes']
			restype = kwargs['restype']
			argtypes = [c_void_p, c_void_p] + argtypes
		except KeyError:
			restype, argtypes, argtype_encodings = parse_types(type_encoding)
			if len(args) != len(argtypes) - 2:
				raise TypeError('expected %i arguments, got %i' % (len(argtypes) - 2, len(args)))
			# Automatically convert Python strings to NSString etc. for object arguments
			# (this is a no-op for arguments that are already `ObjCInstance` objects):
			args = tuple(_auto_wrap(a, argtype_encodings[i], argtypes[i+2]) for i, a in enumerate(args))

		if not LP64 and restype and issubclass(restype, Structure):
			retval = restype()
			objc_msgSend_stret = c['objc_msgSend_stret']
			objc_msgSend_stret.argtypes = [c_void_p] + argtypes
			objc_msgSend_stret.restype = None
			objc_msgSend_stret(byref(retval), obj.ptr, sel(self.sel_name), *args)
			return retval
		else:
			# NOTE: In order to be a little more thread-safe, we need a "private" handle for objc_msgSend(...).
			# Otherwise, a different thread could modify argtypes/restype before the call is made...
			objc_msgSend = self._objc_msgSend
			if not objc_msgSend:
				objc_msgSend = c['objc_msgSend']
				objc_msgSend.argtypes = argtypes
				objc_msgSend.restype = restype
				# Cache the prepared function:
				self._objc_msgSend = objc_msgSend

			res = objc_msgSend(obj.ptr, sel(self.sel_name), *args)
			return_type_enc = chr(type_encoding[0]) if PY3 else type_encoding[0]
			if res and return_type_enc == '@':
				# If an object is returned, wrap the pointer in an ObjCInstance:
				if res == obj.ptr:
					return obj
				return ObjCInstance(res)
			if restype == c_void_p and isinstance(res, int):
				res = c_void_p(res)
			return res

#Some commonly-used Foundation/UIKit classes:
NSObject = ObjCClass('NSObject')
NSDictionary = ObjCClass('NSDictionary')
NSMutableDictionary = ObjCClass('NSMutableDictionary')
NSArray = ObjCClass('NSArray')
NSMutableArray = ObjCClass('NSMutableArray')
NSSet = ObjCClass('NSSet')
NSMutableSet = ObjCClass('NSMutableSet')
NSString = ObjCClass('NSString')
NSMutableString = ObjCClass('NSMutableString')
NSData = ObjCClass('NSData')
NSMutableData = ObjCClass('NSMutableData')
NSNumber = ObjCClass('NSNumber')
NSURL = ObjCClass('NSURL')
NSEnumerator = ObjCClass('NSEnumerator')
NSThread = ObjCClass('NSThread')
NSBundle = ObjCClass('NSBundle')

UIColor = ObjCClass('UIColor')
UIImage = ObjCClass('UIImage')
UIBezierPath = ObjCClass('UIBezierPath')
UIApplication = ObjCClass('UIApplication')
UIView = ObjCClass('UIView')

def load_framework(name):
	return NSBundle.bundleWithPath_('/System/Library/Frameworks/%s.framework' % (name,)).load()

# These are hard-coded for __dir__ (listing all NSObject methods dynamically would add tons of cruft from categories)
# NOTE: This only includes *commonly-used* methods (a lot of this is pretty low-level runtime stuff that isn't needed
#       very often. It can still be listed when calling dir() on an actual instance of NSObject)
NSObject_class_methods = ['alloc', 'new', 'superclass', 'isSubclassOfClass_', 'instancesRespondToSelector_', 'description', 'cancelPreviousPerformRequestsWithTarget_', 'cancelPreviousPerformRequestsWithTarget_selector_object_']
NSObject_instance_methods = ['init', 'copy', 'mutableCopy', 'dealloc', 'performSelector_withObject_afterDelay_', 'performSelectorOnMainThread_withObject_waitUntilDone_', 'performSelectorInBackground_withObject_']

class _block_descriptor (Structure):
	_fields_ = [('reserved', c_ulong), ('size', c_ulong), ('copy_helper', c_void_p), ('dispose_helper', c_void_p), ('signature', c_char_p)]

class ObjCBlock (object):
	def __init__(self, func, restype=None, argtypes=None):
		if not callable(func):
			raise TypeError('%s is not callable' % func)
		if argtypes is None:
			argtypes = []
		InvokeFuncType = ctypes.CFUNCTYPE(restype, *argtypes)
		class block_literal(Structure):
			_fields_ = [('isa', c_void_p), ('flags', c_int), ('reserved', c_int), ('invoke', InvokeFuncType), ('descriptor', _block_descriptor)]
		block = block_literal()
		block.flags = (1<<28)
		block.invoke = InvokeFuncType(func)
		block.isa = ObjCClass('__NSGlobalBlock__').ptr
		self.func = func
		self._as_parameter_ = block if LP64 else byref(block)

	@classmethod
	def from_param(cls, param):
		if isinstance(param, ObjCBlock) or param is None:
			return param
		elif callable(param):
			block = ObjCBlock(param)
			# Put a reference to the block into the function, so it doesn't get deallocated prematurely...
			param._block = block
			return block
		raise TypeError('cannot convert parameter to block')

	def __call__(self, *args):
		return self.func(*args)

type_encodings['@?'] = ObjCBlock


def ns(py_obj):
	'''Convert common Python objects to their ObjC equivalents, i.e. str => NSString, int/float => NSNumber, list => NSMutableArray, dict => NSMutableDictionary, bytearray => NSData, set => NSMutableSet. Nested structures (list/dict/set) are supported. If an object is already an instance of ObjCInstance, it is left untouched.
		'''
	if isinstance(py_obj, ObjCInstance):
		return py_obj
	if isinstance(py_obj, c_void_p):
		return ObjCInstance(py_obj)
	if hasattr(py_obj, '_objc_ptr'):
		return ObjCInstance(py_obj)

	if PY3:
		if isinstance(py_obj, str):
			return NSString.stringWithUTF8String_(py_obj.encode('utf-8'))
		if isinstance(py_obj, bytes):
			return NSData.dataWithBytes_length_(py_obj, len(py_obj))
	else:
		if isinstance(py_obj, str):
			return NSString.stringWithUTF8String_(py_obj)
		if isinstance(py_obj, unicode):
			return NSString.stringWithUTF8String_(py_obj.encode('utf-8'))
		if isinstance(py_obj, bytearray):
			return NSData.dataWithBytes_length_(str(py_obj), len(py_obj))
	if isinstance(py_obj, int):
		return NSNumber.numberWithInt_(py_obj)
	if isinstance(py_obj, float):
		return NSNumber.numberWithDouble_(py_obj)
	if isinstance(py_obj, bool):
		return NSNumber.numberWithBool_(py_obj)
	if isinstance(py_obj, list):
		arr = NSMutableArray.array()
		for obj in py_obj:
			arr.addObject_(ns(obj))
		return arr
	if isinstance(py_obj, set):
		s = NSMutableSet.set()
		for obj in py_obj:
			s.addObject_(ns(obj))
		return s
	if isinstance(py_obj, dict):
		dct = NSMutableDictionary.dictionary()
		for key, value in (py_obj.items() if PY3 else py_obj.iteritems()):
			dct.setObject_forKey_(ns(value), ns(key))
		return dct

def nsurl(url_or_path):
	if not isinstance(url_or_path, basestring):
		raise TypeError('expected a string')
	if ':' in url_or_path:
		return NSURL.URLWithString_(ns(url_or_path))
	return NSURL.fileURLWithPath_(ns(url_or_path))

def nsdata_to_bytes(data):
	if not isinstance(data, ObjCInstance) or not data.isKindOfClass_(NSData):
		raise TypeError('expected an NSData object')
	_len = data.length()
	if _len == 0:
		return b''
	ArrayType = ctypes.c_char * _len
	buffer = ArrayType()
	data.getBytes_length_(byref(buffer), _len)
	return buffer[:_len]

def uiimage_to_png(img):
	if not isinstance(img, ObjCInstance) or not img.isKindOfClass_(UIImage):
		raise TypeError('expected a UIImage object')
	UIImagePNGRepresentation = c.UIImagePNGRepresentation
	UIImagePNGRepresentation.restype = c_void_p
	UIImagePNGRepresentation.argtypes = [c_void_p]
	data = ObjCInstance(UIImagePNGRepresentation(img))
	return nsdata_to_bytes(data)

def retain_global(obj):
	'''Keep an object alive'''
	_retained_globals.append(obj)

def release_global(obj):
	try:
		_retained_globals.remove(obj)
	except ValueError:
		pass

def OMMainThreadDispatcher_invoke_imp(self, cmd):
	if _tracefunc:
		sys.settrace(_tracefunc)
	self_instance = ObjCInstance(self)
	func = self_instance.func
	args = self_instance.args
	kwargs = self_instance.kwargs
	retval = func(*args, **kwargs)
	self_instance.retval = retval


OMMainThreadDispatcher_name = b'OMMainThreadDispatcher_3' if PY3 else 'OMMainThreadDispatcher'
try:
	OMMainThreadDispatcher = ObjCClass(OMMainThreadDispatcher_name)
except ValueError:
	IMPTYPE = ctypes.CFUNCTYPE(None, c_void_p, c_void_p)
	imp = IMPTYPE(OMMainThreadDispatcher_invoke_imp)
	retain_global(imp)
	NSObject = ObjCClass('NSObject')
	class_ptr = objc_allocateClassPair(NSObject.ptr, OMMainThreadDispatcher_name, 0)
	class_addMethod(class_ptr, sel('invoke'), imp, b'v16@0:0')
	objc_registerClassPair(class_ptr)
	OMMainThreadDispatcher = ObjCClass(OMMainThreadDispatcher_name)

def on_main_thread(func):
	if not callable(func):
		raise TypeError('expected a callable')
	@functools.wraps(func)
	def new_func(*args, **kwargs):
		if NSThread.isMainThread(restype=c_bool, argtypes=[]):
			return func(*args, **kwargs)
		dispatcher = OMMainThreadDispatcher.new()
		dispatcher.func = func
		dispatcher.args = args
		dispatcher.kwargs = kwargs
		dispatcher.retval = None
		dispatcher.performSelectorOnMainThread_withObject_waitUntilDone_(sel('invoke'), None, True)
		retval = dispatcher.retval
		dispatcher.release()
		return retval
	return new_func

def _add_method(method, class_ptr, superclass, basename, protocols, is_classmethod=False):
	'''Helper function for create_objc_class, don't use directly (will usually crash)!'''
	if hasattr(method, 'selector'):
		sel_name = method.selector
	else:
		method_name = method.__name__
		if method_name.startswith(basename + '_'):
			method_name = method_name[len(basename)+1:]
		sel_name = method_name.replace('_', ':')
	type_encoding = None
	if hasattr(method, 'encoding'):
		# Explicit encoding was provided, trust that unconditionally...
		type_encoding = method.encoding
	else:
		# No explicit encoding given, we have to guess...
		# First, try to derive it from overridden methods in the superclass(es)...
		if is_classmethod:
			superclass_method = class_getClassMethod(superclass, sel(sel_name))
		else:
			superclass_method = class_getInstanceMethod(superclass, sel(sel_name))
		if superclass_method:
			type_encoding = method_getTypeEncoding(superclass_method)
		else:
			# Try to find a matching method in one of the protocols
			for protocol_name in protocols:
				if PY3 and isinstance(protocol_name, str):
					protocol_name = protocol_name.encode('ascii')
				protocol = objc_getProtocol(protocol_name)
				if protocol:
					# Try optional method first...
					method_desc = protocol_getMethodDescription(protocol, sel(sel_name), False, True)
					if not method_desc or not method_desc.types:
						#... then required method
						method_desc = protocol_getMethodDescription(protocol, sel(sel_name), True, True)
					if method_desc and method_desc.types:
						type_encoding = method_desc.types
						break
		if not type_encoding:
			# Fall back to "action" type encoding as the default, i.e. void return type, all arguments are objects...
			num_args = len(re.findall(':', sel_name))
			type_encoding = 'v%i@0:8%s' % (sizeof(c_void_p) * (num_args + 2), ''.join('@%i' % ((i+2) * sizeof(c_void_p),) for i in xrange(num_args)))

	if hasattr(method, 'restype') and hasattr(method, 'argtypes'):
		restype = method.restype
		argtypes = [c_void_p, c_void_p] + method.argtypes
	else:
		parsed_types = parse_types(type_encoding)
		restype = parsed_types[0]
		argtypes = parsed_types[1]
	# Check if the number of arguments derived from the selector matches the actual function:
	argspec = inspect.getargspec(method)
	if len(argspec.args) != len(argtypes):
		raise ValueError('%s has %i arguments (expected %i)' % (method, len(argspec.args), len(argtypes)))
	IMPTYPE = ctypes.CFUNCTYPE(restype, *argtypes)
	imp = IMPTYPE(method)
	retain_global(imp)
	if PY3 and isinstance(type_encoding, str):
		type_encoding = type_encoding.encode('ascii')
	class_addMethod(class_ptr, sel(sel_name), imp, type_encoding)

def create_objc_class(name, superclass=NSObject, methods=[], classmethods=[], protocols=[], debug=True):
	'''Create and return a new Objective-C class'''
	basename = name
	if debug:
		# When debug is True (the default) and a class with the given name already exists in the runtime,
		# append an incrementing numeric suffix, until a class name is found that doesn't exist yet.
		# While this does leak some memory, it makes development much easier. Note however that the returned
		# class may not have the name you passed in (use the return value directly instead of relying on the name)
		suffix = 1
		while True:
			try:
				existing_class = ObjCClass(name)
				suffix += 1
				name = '%s_%i' % (basename, suffix)
			except ValueError:
				break
	else:
		# When debug is False, assume that any class is created only once, and return an existing class
		# with the given name. Note that this ignores all other parameters. This is intended to avoid
		# unnecessary memory leaks when the class definition doesn't change anymore.
		try:
			existing_class = ObjCClass(basename)
			return existing_class
		except ValueError:
			pass
	if PY3 and isinstance(name, str):
		name = name.encode('ascii')
	class_ptr = objc_allocateClassPair(superclass, name, 0)

	for method in methods:
		_add_method(method, class_ptr, superclass, basename, protocols)

	objc_registerClassPair(class_ptr)

	for method in classmethods:
		metaclass = object_getClass(class_ptr)
		super_metaclass = object_getClass(class_getSuperclass(class_ptr))
		_add_method(method, metaclass, super_metaclass, basename, [], True)
	return ObjCClass(name)

def settrace(func):
	# used for on_main_thread()
	global _tracefunc
	_tracefunc = func