State Machine Builder and eip connection machine

This implements an abstract definition of a LEAP state machine,
and refactors eip connections to use it.

1 files changed, 125 insertions, 0 deletions

diff --git a/src/leap/bitmask/services/connections.py b/src/leap/bitmask/services/connections.py
new file mode 100644
index 00000000..f3ab9e8e
--- /dev/null
+++ b/src/leap/bitmask/services/connections.py
@@ -0,0 +1,125 @@
+# -*- coding: utf-8 -*-
+# connections.py
+# Copyright (C) 2013 LEAP
+#
+# 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 3 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, see <http://www.gnu.org/licenses/>.
+"""
+Abstract LEAP connections.
+"""
+# TODO use zope.interface instead
+from abc import ABCMeta
+
+from PySide import QtCore
+
+from leap.common.check import leap_assert
+
+_tr = QtCore.QObject().tr
+
+
+class State(object):
+    """
+    Abstract state class
+    """
+    __metaclass__ = ABCMeta
+
+    label = None
+    short_label = None
+
+"""
+The different services should declare a ServiceConnection class that
+inherits from AbstractLEAPConnection, so an instance of such class
+can be used to inform the StateMachineBuilder of the particularities
+of the state transitions for each particular connection.
+
+In the future, we will extend this class to allow composites in connections,
+so we can apply conditional logic to the transitions.
+"""
+
+
+class AbstractLEAPConnection(object):
+    """
+    Abstract LEAP Connection class.
+
+    This class is likely to undergo heavy transformations
+    in the coming releases, to better accomodate the use cases
+    of the different connections that we use in the Bitmask
+    client.
+    """
+    __metaclass__ = ABCMeta
+
+    _connection_name = None
+
+    @property
+    def name(self):
+        """
+        Name of the connection
+        """
+        con_name = self._connection_name
+        leap_assert(con_name is not None)
+        return con_name
+
+    _qtsigs = None
+
+    @property
+    def qtsigs(self):
+        """
+        Object that encapsulates the Qt Signals emitted
+        by this connection.
+        """
+        return self._qtsigs
+
+    # XXX for conditional transitions with composites,
+    #     we might want to add
+    #     a field with dependencies: what this connection
+    #     needs for (ON) state.
+    # XXX Look also at child states in the state machine.
+    #depends = ()
+
+    # Signals that derived classes
+    # have to implement.
+
+    # Commands
+    do_connect_signal = None
+    do_disconnect_signal = None
+
+    # Intermediate stages
+    connecting_signal = None
+    disconnecting_signal = None
+
+    # Complete stages
+    connected_signal = None
+    disconnected_signal = None
+
+    # Bypass stages
+    connection_died_signal = None
+
+    class Disconnected(State):
+        """Disconnected state"""
+        label = _tr("Disconnected")
+        short_label = _tr("OFF")
+
+    class Connected(State):
+        """Connected state"""
+        label = _tr("Connected")
+        short_label = _tr("ON")
+
+    class Connecting(State):
+        """Connecting state"""
+        label = _tr("Connecting")
+        short_label = _tr("...")
+
+    class Disconnecting(State):
+        """Disconnecting state"""
+        label = _tr("Disconnecting")
+        short_label = _tr("...")