Add catch-all '*' to event handlers

qubes/events.py

@@ -135,7 +135,10 @@ class Emitter(object):
         for cls in order:
             if not hasattr(cls, '__handlers__'):
                 continue
-            for func in sorted(cls.__handlers__[event],
+            handlers = cls.__handlers__[event]
+            if '*' in cls.__handlers__:
+                handlers = cls.__handlers__['*'] | handlers
+            for func in sorted(handlers,
                     key=(lambda handler: hasattr(handler, 'ha_bound')),
                     reverse=True):
                 effect = func(self, event, *args, **kwargs)

qubes/tests/events.py

@@ -82,3 +82,27 @@ class TC_00_Emitter(qubes.tests.QubesTestCase):
 
         self.assertItemsEqual(effect,
             ('testvalue1', 'testvalue2', 'testvalue3', 'testvalue4'))
+
+    def test_004_catch_all(self):
+        # need something mutable
+        testevent_fired = [0]
+
+        def on_all(subject, event, *args, **kwargs):
+            # pylint: disable=unused-argument
+            testevent_fired[0] += 1
+
+        def on_foo(subject, event, *args, **kwargs):
+            # pylint: disable=unused-argument
+            testevent_fired[0] += 1
+
+        emitter = qubes.events.Emitter()
+        emitter.add_handler('*', on_all)
+        emitter.add_handler('foo', on_foo)
+        emitter.events_enabled = True
+        emitter.fire_event('testevent')
+        self.assertEqual(testevent_fired[0], 1)
+        emitter.fire_event('foo')
+        # now catch-all and foo should be executed
+        self.assertEqual(testevent_fired[0], 3)
+        emitter.fire_event('bar')
+        self.assertEqual(testevent_fired[0], 4)