def __undo(self, update_history=True):
"""
Access the last committed transaction, and revert the data to the
state before the transaction was committed.
"""
txn = self.undoq.pop()
self.redoq.append(txn)
transaction = txn
db = self.db
subitems = transaction.get_recnos(reverse=True)
# Process all records in the transaction
for record_id in subitems:
(key, trans_type, handle, old_data, new_data) = \
pickle.loads(self.undodb[record_id])
if key == REFERENCE_KEY:
self.undo_reference(old_data, handle, self.mapbase[key])
else:
self.undo_data(old_data, handle, self.mapbase[key], db.emit,
_SIGBASE[key])
# Notify listeners
if db.undo_callback:
if self.undo_count > 0:
db.undo_callback(
_("_Undo %s") % self.undoq[-1].get_description())
else:
db.undo_callback(None)
if db.redo_callback:
db.redo_callback(_("_Redo %s") % transaction.get_description())
if update_history and db.undo_history_callback:
db.undo_history_callback()
return True
def __redo(self, db=None, update_history=True):
"""
Access the last undone transaction, and revert the data to the state
before the transaction was undone.
"""
txn = self.redoq.pop()
self.undoq.append(txn)
transaction = txn
db = self.db
subitems = transaction.get_recnos()
# Process all records in the transaction
for record_id in subitems:
(key, trans_type, handle, old_data, new_data) = \
pickle.loads(self.undodb[record_id])
if key == REFERENCE_KEY:
self.undo_reference(new_data, handle, self.mapbase[key])
else:
self.undo_data(new_data, handle, self.mapbase[key],
db.emit, _SIGBASE[key])
# Notify listeners
if db.undo_callback:
db.undo_callback(_("_Undo %s")
% transaction.get_description())
if db.redo_callback:
if self.redo_count > 1:
new_transaction = self.redoq[-2]
db.redo_callback(_("_Redo %s")
% new_transaction.get_description())
else:
db.redo_callback(None)
if update_history and db.undo_history_callback:
db.undo_history_callback()
return True