Fixing some race conditions where the user could get the UI into a very funky state

diff --git a/src/session.py b/src/session.py
index 8dbdba0..f867f0d 100644 (file)
--- a/src/session.py
+++ b/src/session.py
@@ -60,6 +60,7 @@ class Draft(QtCore.QObject):
                self._contacts = {}
                self._pool = pool
                self._backend = backend
+               self._busyReason = None
 
        def send(self, text):
                assert 0 < len(self._contacts), "No contacts selected"
@@ -79,6 +80,8 @@ class Draft(QtCore.QObject):
                le.start()
 
        def add_contact(self, contactId, title, description, numbersWithDescriptions):
+               if self._busyReason is not None:
+                       raise RuntimeError("Please wait for %r" % self._busyReason)
                if contactId in self._contacts:
                        _moduleLogger.info("Adding duplicate contact %r" % contactId)
                        # @todo Remove this evil hack to re-popup the dialog
@@ -89,6 +92,8 @@ class Draft(QtCore.QObject):
                self.recipientsChanged.emit()
 
        def remove_contact(self, contactId):
+               if self._busyReason is not None:
+                       raise RuntimeError("Please wait for %r" % self._busyReason)
                assert contactId in self._contacts, "Contact missing"
                del self._contacts[contactId]
                self.recipientsChanged.emit()
@@ -118,36 +123,53 @@ class Draft(QtCore.QObject):
                self._contacts[cid].selectedNumber = number
 
        def clear(self):
+               if self._busyReason is not None:
+                       raise RuntimeError("Please wait for %r" % self._busyReason)
+               self._clear()
+
+       def _clear(self):
                oldContacts = self._contacts
                self._contacts = {}
                if oldContacts:
                        self.recipientsChanged.emit()
 
+       @contextlib.contextmanager
+       def _busy(self, message):
+               if self._busyReason is not None:
+                       raise RuntimeError("Already busy doing %r" % self._busyReason)
+               try:
+                       self._busyReason = message
+                       yield
+               finally:
+                       self._busyReason = None
+
        def _send(self, numbers, text):
                self.sendingMessage.emit()
                try:
-                       with notify_busy(self._errorLog, "Sending Text"):
-                               yield (
-                                       self._backend[0].send_sms,
-                                       (numbers, text),
-                                       {},
-                               )
-                       self.sentMessage.emit()
-                       self.clear()
+                       with self._busy("Sending Text"):
+                               with notify_busy(self._errorLog, "Sending Text"):
+                                       yield (
+                                               self._backend[0].send_sms,
+                                               (numbers, text),
+                                               {},
+                                       )
+                               self.sentMessage.emit()
+                               self._clear()
                except Exception, e:
                        self.error.emit(str(e))
 
        def _call(self, number):
                self.calling.emit()
                try:
-                       with notify_busy(self._errorLog, "Calling"):
-                               yield (
-                                       self._backend[0].call,
-                                       (number, ),
-                                       {},
-                               )
-                       self.called.emit()
-                       self.clear()
+                       with self._busy("Calling"):
+                               with notify_busy(self._errorLog, "Calling"):
+                                       yield (
+                                               self._backend[0].call,
+                                               (number, ),
+                                               {},
+                                       )
+                               self.called.emit()
+                               self._clear()
                except Exception, e:
                        self.error.emit(str(e))