diff -r 000000000000 -r 7bb070e90138 src/pyams_skin/skin.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pyams_skin/skin.py	Wed Dec 05 13:13:47 2018 +0100
@@ -0,0 +1,158 @@
+#
+# Copyright (c) 2008-2015 Thierry Florac <tflorac AT ulthar.net>
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+
+__docformat__ = 'restructuredtext'
+
+# import standard library
+import logging
+logger = logging.getLogger('PyAMS (skin)')
+
+# import interfaces
+from pyams_skin.interfaces import ISkin, ISkinnable, IUserSkinnable, SkinChangedEvent
+from pyams_skin.layer import IBaseLayer, IPyAMSLayer
+from pyams_utils.interfaces.site import ISiteRoot
+from zope.traversing.interfaces import IBeforeTraverseEvent
+
+# import packages
+from pyams_utils.registry import utility_config
+from pyams_utils.traversing import get_parent
+from pyams_utils.zodb import volatile_property
+from pyramid.events import subscriber
+from pyramid.threadlocal import get_current_request
+from pyramid_zope_request import PyramidPublisherRequest
+from zope.interface import implementer, directlyProvidedBy, directlyProvides
+from zope.schema.fieldproperty import FieldProperty
+
+from pyams_skin import _
+
+
+@implementer(ISkinnable)
+class SkinnableContent(object):
+    """Skinnable content base class"""
+
+    _inherit_skin = FieldProperty(ISkinnable['inherit_skin'])
+    _skin = FieldProperty(IUserSkinnable['skin'])
+
+    @property
+    def can_inherit_skin(self):
+        return get_parent(self, ISkinnable, allow_context=False) is not None
+
+    @property
+    def inherit_skin(self):
+        return self._inherit_skin if self.can_inherit_skin else False
+
+    @inherit_skin.setter
+    def inherit_skin(self, value):
+        if self.can_inherit_skin:
+            self._inherit_skin = value
+        del self.skin_parent
+
+    @property
+    def no_inherit_skin(self):
+        return not bool(self.inherit_skin)
+
+    @no_inherit_skin.setter
+    def no_inherit_skin(self, value):
+        self.inherit_skin = not bool(value)
+
+    @property
+    def skin(self):
+        if not self.inherit_skin:
+            return self._skin
+        else:
+            return self.skin_parent.skin
+
+    @skin.setter
+    def skin(self, value):
+        if not self.inherit_skin:
+            self._skin = value
+        del self.skin_parent
+
+    @volatile_property
+    def skin_parent(self):
+        if (not self._inherit_skin) and self.skin:
+            return self
+        parent = get_parent(self, ISkinnable, allow_context=False)
+        if parent is not None:
+            return parent.skin_parent
+
+    def get_skin(self, request=None):
+        parent = self.skin_parent
+        if parent is self:
+            return self.skin
+        elif parent is not None:
+            skin = parent.skin
+            if skin is not None:
+                if request is None:
+                    request = get_current_request()
+                return request.registry.queryUtility(ISkin, skin)
+
+
+@implementer(IUserSkinnable)
+class UserSkinnableContent(SkinnableContent):
+    """User skinnable content base class"""
+
+
+def apply_skin(request, skin):
+    """Apply given skin to request"""
+
+    def _apply(request, skin):
+        ifaces = [iface for iface in directlyProvidedBy(request)
+                  if not issubclass(iface, IBaseLayer)]
+        # Add the new skin.
+        if isinstance(skin, str):
+            skin = request.registry.queryUtility(ISkin, skin)
+        if skin is not None:
+            ifaces.append(skin.layer)
+            directlyProvides(request, *ifaces)
+            logger.debug("Applied skin {0!r} to request {1!r}".format(skin.label, request))
+
+    _apply(request, skin)
+    if isinstance(request, PyramidPublisherRequest):
+        request = request._request
+        _apply(request, skin)
+    else:
+        request.registry.notify(SkinChangedEvent(request))
+        request.annotations['__skin__'] = skin
+
+
+@subscriber(IBeforeTraverseEvent, context_selector=ISkinnable)
+def handle_content_skin(event):
+    """Apply skin when traversing skinnable object"""
+    request = event.request
+    skinnable = event.object
+    if not skinnable.inherit_skin:
+        skin = skinnable.get_skin(request)
+        if skin is not None:
+            apply_skin(request, skin)
+
+
+@subscriber(IBeforeTraverseEvent, context_selector=ISiteRoot)
+def handle_root_skin(event):
+    """Apply skin when traversing site root"""
+    context = event.object
+    if not ISkinnable.providedBy(context):
+        apply_skin(event.request, PyAMSSkin)
+    elif context.skin is None:
+        apply_skin(event.request, PyAMSSkin)
+
+
+#
+# Base and default skins
+#
+
+@utility_config(name='PyAMS base skin', provides=ISkin)
+class PyAMSSkin(object):
+    """PyAMS base skin"""
+
+    label = _("PyAMS base skin")
+    layer = IPyAMSLayer