1 # -*- Mode: Python; py-indent-offset: 4 -*-
2 # vim: tabstop=4 shiftwidth=4 expandtab
4 # Copyright (C) 2005-2009 Johan Dahlin <johan@gnome.org>
6 # types.py: base types for introspected items.
8 # This library is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU Lesser General Public
10 # License as published by the Free Software Foundation; either
11 # version 2.1 of the License, or (at your option) any later version.
13 # This library is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 # Lesser General Public License for more details.
18 # You should have received a copy of the GNU Lesser General Public
19 # License along with this library; if not, write to the Free Software
20 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
23 from __future__ import absolute_import
26 from . import _gobject
33 register_interface_info, \
34 hook_up_vfunc_implementation
39 if sys.version_info > (3, 0):
41 return hasattr(obj, '__call__')
46 def function(*args, **kwargs):
47 return info.invoke(*args, **kwargs)
48 function.__info__ = info
49 function.__name__ = info.get_name()
50 function.__module__ = info.get_namespace()
55 class NativeVFunc(object):
57 def __init__(self, info):
60 def __get__(self, instance, klass):
61 def native_vfunc(*args, **kwargs):
62 return self._info.invoke(klass.__gtype__, *args, **kwargs)
63 native_vfunc.__info__ = self._info
64 native_vfunc.__name__ = self._info.get_name()
65 native_vfunc.__module__ = self._info.get_namespace()
70 def Constructor(info):
72 def constructor(cls, *args, **kwargs):
73 cls_name = info.get_container().get_name()
74 if cls.__name__ != cls_name:
75 raise TypeError('%s constructor cannot be used to create instances of a subclass' % cls_name)
76 return info.invoke(cls, *args, **kwargs)
78 constructor.__info__ = info
79 constructor.__name__ = info.get_name()
80 constructor.__module__ = info.get_namespace()
85 class MetaClassHelper(object):
87 def _setup_constructors(cls):
88 for method_info in cls.__info__.get_methods():
89 if method_info.is_constructor():
90 name = method_info.get_name()
91 constructor = classmethod(Constructor(method_info))
92 setattr(cls, name, constructor)
94 def _setup_methods(cls):
95 for method_info in cls.__info__.get_methods():
96 name = method_info.get_name()
97 function = Function(method_info)
98 if method_info.is_method():
100 elif method_info.is_constructor():
103 method = staticmethod(function)
104 setattr(cls, name, method)
106 def _setup_fields(cls):
107 for field_info in cls.__info__.get_fields():
108 name = field_info.get_name().replace('-', '_')
109 setattr(cls, name, property(field_info.get_value, field_info.set_value))
111 def _setup_constants(cls):
112 for constant_info in cls.__info__.get_constants():
113 name = constant_info.get_name()
114 value = constant_info.get_value()
115 setattr(cls, name, value)
117 def _setup_vfuncs(cls):
118 for vfunc_name, py_vfunc in cls.__dict__.items():
119 if not vfunc_name.startswith("do_") or not callable(py_vfunc):
122 # If a method name starts with "do_" assume it is a vfunc, and search
123 # in the base classes for a method with the same name to override.
124 # Recursion is necessary as overriden methods in most immediate parent
125 # classes may shadow vfuncs from classes higher in the hierarchy.
127 for base in cls.__mro__:
128 method = getattr(base, vfunc_name, None)
129 if method is not None and hasattr(method, '__info__') and \
130 isinstance(method.__info__, VFuncInfo):
131 vfunc_info = method.__info__
134 # If we did not find a matching method name in the bases, we might
135 # be overriding an interface virtual method. Since interfaces do not
136 # provide implementations, there will be no method attribute installed
137 # on the object. Instead we have to search through
138 # InterfaceInfo.get_vfuncs(). Note that the infos returned by
139 # get_vfuncs() use the C vfunc name (ie. there is no "do_" prefix).
140 if vfunc_info is None:
141 vfunc_info = find_vfunc_info_in_interface(cls.__bases__, vfunc_name[len("do_"):])
143 if vfunc_info is not None:
144 assert vfunc_name == ('do_' + vfunc_info.get_name())
145 # Check to see if there are vfuncs with the same name in the bases.
146 # We have no way of specifying which one we are supposed to override.
147 ambiguous_base = find_vfunc_conflict_in_bases(vfunc_info, cls.__bases__)
148 if ambiguous_base is not None:
149 base_info = vfunc_info.get_container()
150 raise TypeError('Method %s() on class %s.%s is ambiguous '
151 'with methods in base classes %s.%s and %s.%s' %
153 cls.__info__.get_namespace(),
154 cls.__info__.get_name(),
155 base_info.get_namespace(),
156 base_info.get_name(),
157 ambiguous_base.__info__.get_namespace(),
158 ambiguous_base.__info__.get_name()
160 hook_up_vfunc_implementation(vfunc_info, cls.__gtype__,
163 def _setup_native_vfuncs(cls):
164 # Only InterfaceInfo and ObjectInfo have the get_vfuncs() method.
165 # We skip InterfaceInfo because interfaces have no implementations for vfuncs.
166 # Also check if __info__ in __dict__, not hasattr('__info__', ...)
167 # because we do not want to accidentally retrieve __info__ from a base class.
168 class_info = cls.__dict__.get('__info__')
169 if class_info is None or not isinstance(class_info, ObjectInfo):
172 for vfunc_info in class_info.get_vfuncs():
173 name = 'do_%s' % vfunc_info.get_name()
174 value = NativeVFunc(vfunc_info)
175 setattr(cls, name, value)
178 def find_vfunc_info_in_interface(bases, vfunc_name):
180 # All wrapped interfaces inherit from GInterface.
181 # This can be seen in IntrospectionModule.__getattr__() in module.py.
182 # We do not need to search regular classes here, only wrapped interfaces.
183 # We also skip GInterface, because it is not wrapped and has no __info__ attr.
184 if base is _gobject.GInterface or\
185 not issubclass(base, _gobject.GInterface) or\
186 not isinstance(base.__info__, InterfaceInfo):
189 for vfunc in base.__info__.get_vfuncs():
190 if vfunc.get_name() == vfunc_name:
193 vfunc = find_vfunc_info_in_interface(base.__bases__, vfunc_name)
194 if vfunc is not None:
200 def find_vfunc_conflict_in_bases(vfunc, bases):
202 if not hasattr(klass, '__info__') or \
203 not hasattr(klass.__info__, 'get_vfuncs'):
205 vfuncs = klass.__info__.get_vfuncs()
206 vfunc_name = vfunc.get_name()
208 if v.get_name() == vfunc_name and v != vfunc:
211 aklass = find_vfunc_conflict_in_bases(vfunc, klass.__bases__)
212 if aklass is not None:
217 class GObjectMeta(_gobject.GObjectMeta, MetaClassHelper):
219 def __init__(cls, name, bases, dict_):
220 super(GObjectMeta, cls).__init__(name, bases, dict_)
221 is_gi_defined = False
222 if cls.__module__ == 'gi.repository.' + cls.__info__.get_namespace():
225 is_python_defined = False
226 if not is_gi_defined and cls.__module__ != GObjectMeta.__module__:
227 is_python_defined = True
229 if is_python_defined:
233 cls._setup_constants()
234 cls._setup_native_vfuncs()
236 if isinstance(cls.__info__, ObjectInfo):
238 cls._setup_constructors()
239 elif isinstance(cls.__info__, InterfaceInfo):
240 register_interface_info(cls.__info__.get_g_type())
247 """Compute the class precedence list (mro) according to C3
249 Based on http://www.python.org/download/releases/2.3/mro/
250 Modified to consider that interfaces don't create the diamond problem
252 # TODO: If this turns out being too slow, consider using generators
254 bases_of_subclasses = [[C]]
257 bases_of_subclasses += list(map(mro, C.__bases__)) + [list(C.__bases__)]
259 while bases_of_subclasses:
260 for subclass_bases in bases_of_subclasses:
261 candidate = subclass_bases[0]
262 not_head = [s for s in bases_of_subclasses if candidate in s[1:]]
263 if not_head and _gobject.GInterface not in candidate.__bases__:
264 candidate = None # conflict, reject candidate
268 if candidate is None:
269 raise TypeError('Cannot create a consistent method resolution '
272 bases.append(candidate)
274 for subclass_bases in bases_of_subclasses[:]: # remove candidate
275 if subclass_bases and subclass_bases[0] == candidate:
276 del subclass_bases[0]
277 if not subclass_bases:
278 bases_of_subclasses.remove(subclass_bases)
283 class StructMeta(type, MetaClassHelper):
285 def __init__(cls, name, bases, dict_):
286 super(StructMeta, cls).__init__(name, bases, dict_)
288 # Avoid touching anything else than the base class.
289 g_type = cls.__info__.get_g_type()
290 if g_type != _gobject.TYPE_INVALID and g_type.pytype is not None:
295 cls._setup_constructors()
297 for method_info in cls.__info__.get_methods():
298 if method_info.is_constructor() and \
299 method_info.get_name() == 'new' and \
300 not method_info.get_arguments():
301 cls.__new__ = staticmethod(Constructor(method_info))