--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pyams_gis/schema.py	Thu May 18 17:23:48 2017 +0200
@@ -0,0 +1,66 @@
+#
+# Copyright (c) 2008-2017 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 interfaces
+from pyams_gis.interfaces import IGeoPoint, IGeoPointZ, IGeoArea
+from zope.schema.interfaces import IObject
+
+# import packages
+from zope.interface import implementer
+from zope.schema import Object
+
+
+class IGeoPointField(IObject):
+    """GeoPoint schema field interface"""
+
+
+@implementer(IGeoPointField)
+class GeoPointField(Object):
+    """GeoPoint field class"""
+
+    def __init__(self, **kwargs):
+        if 'schema' in kwargs:
+            del kwargs['schema']
+        super(GeoPointField, self).__init__(IGeoPoint, **kwargs)
+
+
+class IGeoPointZField(IObject):
+    """GeoPointZ schema field interface"""
+
+
+@implementer(IGeoPointZField)
+class GeoPointZField(Object):
+    """GeoPointZ field class"""
+
+    def __init__(self, **kwargs):
+        if 'schema' in kwargs:
+            del kwargs['schema']
+        super(GeoPointZField, self).__init__(IGeoPointZ, **kwargs)
+
+
+class IGeoAreaField(IObject):
+    """GeoArea schema field interface"""
+
+
+@implementer(IGeoAreaField)
+class GeoAreaField(Object):
+    """GeoArea field class"""
+
+    def __init__(self, **kwargs):
+        if 'schema' in kwargs:
+            del kwargs['schema']
+        super(GeoAreaField, self).__init__(IGeoArea, **kwargs)