simplify api by abstracting layer changes

owrx/property/__init__.py

@@ -353,10 +353,12 @@ class PropertyCarousel(PropertyDelegator):
         return self.emptyLayer
 
     def addLayer(self, key, value):
+        if key in self.layers and self.layers[key] is self.pm:
+            self.layers[key] = value
+            # switch after introducing the new value
+            self.switch(key)
+        else:
             self.layers[key] = value
-
-    def hasLayer(self, key):
-        return key in self.layers
 
     def removeLayer(self, key):
         if key in self.layers and self.layers[key] is self.pm:

owrx/source/__init__.py

@@ -84,7 +84,7 @@ class SdrProfileCarousel(PropertyCarousel):
         for profile_id, profile in changes.items():
             if profile is PropertyDeleted:
                 self.removeLayer(profile_id)
-            elif not self.hasLayer(profile_id):
+            else:
                 self.addLayer(profile_id, profile)
 
     def _getDefaultLayer(self):

test/property/test_property_carousel.py

@@ -77,12 +77,6 @@ class PropertyCarouselTest(TestCase):
         with self.assertRaises(KeyError):
             pc.switch("doesntmatter")
 
-    def testHasLayer(self):
-        pc = PropertyCarousel()
-        pc.addLayer("testkey", PropertyLayer())
-        self.assertTrue(pc.hasLayer("testkey"))
-        self.assertFalse(pc.hasLayer("otherkey"))
-
     def testRemoveLayer(self):
         pc = PropertyCarousel()
         pl = PropertyLayer(testkey="testvalue")
@@ -117,3 +111,15 @@ class PropertyCarouselTest(TestCase):
         pc = PropertyCarousel()
         with self.assertRaises(PropertyWriteError):
             pc["testkey"] = "testvalue"
+
+    def testSendsChangesIfActiveLayerIsReplaced(self):
+        pc = PropertyCarousel()
+        pl = PropertyLayer(testkey="testvalue")
+        pc.addLayer("x", pl)
+        pc.switch("x")
+        self.assertEqual(pc["testkey"], "testvalue")
+        mock = Mock()
+        pc.wire(mock.method)
+        pl = PropertyLayer(testkey="othervalue")
+        pc.addLayer("x", pl)
+        mock.method.assert_called_once_with({"testkey": "othervalue"})