--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pyams_zodbbrowser/interfaces/__init__.py	Wed Mar 11 12:27:00 2015 +0100
@@ -0,0 +1,145 @@
+#
+# 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 interfaces
+
+# import packages
+from zope.interface import Interface
+
+
+class IObjectHistory(Interface):
+    """History of persistent object state.
+
+    Adapt a persistent object to IObjectHistory.
+    """
+
+    def __len__():
+        """Return the number of history records."""
+
+    def __getitem__(n):
+        """Return n-th history record.
+
+        Records are ordered by age, from latest (index 0) to oldest.
+
+        Each record is a dictonary with at least the following items:
+
+            tid -- transaction ID (a byte string, usually 8 bytes)
+            time -- transaction timestamp (Unix time_t value)
+            user_name -- name of the user responsible for the change
+            description -- short description (often a URL)
+
+        """
+
+    def lastChange(tid=None):
+        """Return the last transaction at or before tid.
+
+        If tid is not specified, returns the very last transaction that
+        modified this object.
+
+        Will raise KeyError if object did not exist before the given
+        transaction.
+        """
+
+    def loadState(tid=None):
+        """Load and return the object's historical state at or before tid.
+
+        Returns the unpicked state, not an actual persistent object.
+        """
+
+    def loadStatePickle(tid=None):
+        """Load and return the object's historical state at or before tid.
+
+        Returns the picked state as a string.
+        """
+
+    def rollback(tid):
+        """Roll back object state to what it was at or before tid."""
+
+
+class IDatabaseHistory(Interface):
+    """History of the entire database.
+
+    Adapt a connection object to IObjectHistory.
+    """
+
+    def __iter__(n):
+        """Return an iterator over the history record.
+
+        Records are ordered by age, from oldest (index 0) to newest.
+
+        Each record provides ZODB.interfaces.an IStorageTransactionInformation.
+        """
+
+
+class IValueRenderer(Interface):
+    """Renderer of attribute values."""
+
+    def render(tid=None, can_link=True):
+        """Render object value to HTML.
+
+        Hyperlinks to other persistent objects will be limited to versions
+        at or older than the specified transaction id (``tid``).
+        """
+
+
+class IStateInterpreter(Interface):
+    """Interprets persistent object state.
+
+    Usually you adapt a tuple (object, state, tid) to IStateInterpreter to
+    figure out how a certain object type represents its state for pickling.
+    The tid may be None or may be a transaction id, and is supplied in case
+    you need to look at states of other objects to make a full sense of this
+    one.
+    """
+
+    def getError():
+        """Return an error message, if there was an error loading this state."""
+
+    def listAttributes():
+        """Return the attributes of this object as tuples (name, value).
+
+        The order of the attributes returned is irrelevant.
+
+        May return None to indicate that this kind of object cannot
+        store attributes.
+        """
+
+    def listItems():
+        """Return the items of this object as tuples (name, value).
+
+        The order of the attributes returned matters.
+
+        Often these are not stored directly, but extracted from an attribute
+        and presented as items for convenience.
+
+        May return None to indicate that this kind of object is not a
+        container and cannot store items.
+        """
+
+    def getParent():
+        """Return the parent of this object."""
+
+    def getName():
+        """Return the name of this object."""
+
+    def asDict():
+        """Return the state expressed as an attribute dictionary.
+
+        The state should combine the attributes and items somehow, to present
+        a complete picture for the purpose of comparing these dictionaries
+        while looking for changes.
+        """