curds: Check if the current playlist has changed from a single spot

This helps reduce code duplication, since we can just call a single
function to handle sending the changed() signal.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

curds/playlist/manager.py

@@ -95,14 +95,19 @@ class PlaylistManager(PlaylistManagerBase):
         self.current = [ self.lookup("Collection") ]
         self.track   = None
 
-    def next(self):
-        self.track = self.current[0].next()
-        while self.track == None and len(self.current) > 1:
-            old = self.current.pop(0)
+    def __current_changed(self, old):
+        if old != self.current[0]:
             old.changed()
             self.current[0].changed()
+
+    def next(self):
+        old = self.current[0]
+        self.track = self.current[0].next()
+        while self.track == None and len(self.current) > 1:
+            self.current.pop(0)
             self.track = self.current[0].next()
         self.lookup("Previous").add(self.track)
+        self.__current_changed(old)
         return self.track
 
     def __peek_pl(self, plist, n):
@@ -159,7 +164,6 @@ class PlaylistManager(PlaylistManagerBase):
             return
         elif plist in self.current:
             self.current.remove(plist)
-        self.current.insert(0, plist)
 
-        old.changed()
-        plist.changed()
+        self.current.insert(0, plist)
+        self.__current_changed(old)

curds/playlist/test_manager.py

@@ -264,6 +264,7 @@ class TestPlaylistManager(unittest.TestCase):
         self.assertEqual(peek[2], glist[ 0])
         self.assertEqual(peek[3], glist[ 1])
 
+        self.cb_change = [ ]
         self.assertEqual(self.playman.next(), plist[-2])
         self.assertEqual(self.playman.next(), plist[-1])
         self.assertEqual(self.playman.current, [ plist, glist, clist ])