Use actions instead of messages in the tutorials

1 files changed, 135 insertions, 0 deletions

diff --git a/src/sugar/tutorius/actions.py b/src/sugar/tutorius/actions.py
new file mode 100644
index 0000000..b48cb8b
--- /dev/null
+++ b/src/sugar/tutorius/actions.py
@@ -0,0 +1,135 @@
+# 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
+"""
+This module defines Actions that can be done and undone on a state
+"""
+
+from dialog import TutoriusDialog
+
+
+class Action(object):
+    """Base class for Actions"""
+    def __init__(self):
+        object.__init__(self)
+
+    def do(self):
+        """
+        Perform the action
+        """
+        raise NotImplementedError("Not implemented")
+
+    def undo(self):
+        """
+        Revert anything the action has changed
+        """
+        pass #Should raise NotImplemented?
+
+
+class DoOnceMixin(object):
+    """Mixin class used to have an action be called only on the first do().
+    
+    To use this mixin, create a new class that derives from this and from
+    the action you want executed only once.
+
+    class ConcreteOnceAction(DoOnceMixin, ConcreteAction):
+        pass
+
+    This ConcreteActions's do() method will only be called on the first do()
+    and the undo() will be callable after do() has been called
+
+    Maybe it would be better off just using a wrapper class instead of this.
+
+    But it was fun to play with.
+
+    Did I mention the wrapper is 25 lines "south" of here? Besides, this mixin
+    class fails at __init__ ..... mixins... right....narwhals!
+    """
+    def __init__(self ):
+        super(DoOnceMixin, self).__init
+        self._called = False
+        self._need_undo = False
+
+    def do(self):
+        """
+        Do the action only on the first time
+        """
+        if not self._called:
+            self._called = True
+            super(DoOnceMixin, self).do()
+            self._need_undo = True
+            
+    def undo(self):
+        """
+        Undo the action if it's been done
+        """
+        if self._need_undo:
+            super(DoOnceMixin, self).undo()
+            self._need_undo = False
+
+class OnceWrapper(object):
+    """Wraps a class to perform an action once only
+    """
+    def __init__(self, action):
+        self._action = action
+        self._called = False
+        self._need_undo = False
+
+    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
+
+class DialogMessage(Action):
+    """Show a dialog!"""
+    def __init__(self, message):
+        super(DialogMessage, self).__init__(self)
+        self._message = message
+        self._dialog = None
+
+    def do(self):
+        """
+            Show the dialog
+        """
+        self._dialog = TutoriusDialog(self._message)
+        self._dialog.set_button_clicked_cb(self._dialog.close_self)
+        self._dialog.set_modal(False)
+        self._dialog.show()
+
+    def undo(self):
+        """
+            Destroy the dialog
+        """
+        if self._dialog:
+            self._dialog.destroy()
+            self._dialog = None
+        
+
+
+class OnceDialogMessage(DoOnceMixin, DialogMessage):
+    """Broken!"""
+    pass