curds: Store the node's parent in the node

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

curds/playlist/node.py

@@ -6,6 +6,7 @@ class PlaylistNode:
         self.icon     = icon
         self.name     = name
         self.next     = None
+        self.parent   = None
         self.prev     = None
 
     def __link_children__(self, b, c):
@@ -24,6 +25,7 @@ class PlaylistNode:
         if len(self.children) > 0:
             prev = self.children[-1]
         self.children.append(child)
+        child.parent = self
         self.__link_children__(prev, child)
         return self.children.index(child)
 
@@ -31,6 +33,7 @@ class PlaylistNode:
         for i, n in enumerate(self.children):
             if child < n:
                 self.children.insert(i, child)
+                child.parent = self
                 self.__link_children__(child, n)
                 return self.children.index(child)
         return self.append_child(child)

curds/playlist/test_node.py

@@ -77,3 +77,18 @@ class TestPlaylistNode(unittest.TestCase):
         self.assertEqual(root.children, [ a, b, c, d ])
         self.assertEqual(a.next, b)
         self.assertEqual(b.prev, a)
+
+    def test_node_parent(self):
+        root = node.PlaylistNode()
+        a = node.PlaylistNode("a")
+        b = node.PlaylistNode("b")
+        c = node.PlaylistNode("c")
+
+        root.append_child(a)
+        a.append_child(b)
+        b.append_child(c)
+
+        self.assertEqual(c.parent, b)
+        self.assertEqual(b.parent, a)
+        self.assertEqual(a.parent, root)
+        self.assertIsNone(root.parent)