LP 439980 : Adding missed actions in previous checkins

1 files changed, 59 insertions, 0 deletions

diff --git a/addons/oncewrapper.py b/addons/oncewrapper.py
new file mode 100644
index 0000000..fb0196f
--- /dev/null
+++ b/addons/oncewrapper.py
@@ -0,0 +1,59 @@
+# Copyright (C) 2009, Tutorius.org
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+from sugar.tutorius.actions import *
+
+class OnceWrapper(Action):
+    """
+    Wraps a class to perform an action once only
+
+    This ConcreteActions's do() method will only be called on the first do()
+    and the undo() will be callable after do() has been called
+    """
+
+    action = TAddonProperty()
+
+    def __init__(self, action):
+        Action.__init__(self)
+        self._called = False
+        self._need_undo = False
+        self.action = action
+
+    def do(self):
+        """
+        Do the action only on the first time
+        """
+        if not self._called:
+            self._called = True
+            self.action.do()
+            self._need_undo = True
+
+    def undo(self):
+        """
+        Undo the action if it's been done
+        """
+        if self._need_undo:
+            self.action.undo()
+            self._need_undo = False
+
+
+__action__ = {
+    'name' : 'OnceWrapper',
+    'display_name' : 'Execute an action only once',
+    'icon' : 'once_wrapper',
+    'class' : OnceWrapper,
+    'mandatoryprops' : ['action'] 
+}