fix PriorityDrawer

src/asyncpygame/_api_impl/priority_drawing.py

@@ -97,8 +97,11 @@ def zorder(self, zorder):
         req = self.__req
         if req.zorder == zorder:
             return
-        req.cancel()
-        self.__req = self.__add_request(req.draw, zorder)
+        if req.cancelled:
+            req.zorder = zorder
+        else:
+            req.cancel()
+            self.__req = self.__add_request(req.draw, zorder)
 
     @property
     def draw(self) -> DrawFunc:

tests/_api_impl/test_priority_drawing.py

@@ -42,3 +42,24 @@ def test_various_zorders():
     req.draw = lambda v: value_list.append(v + v + v)
     d.draw('E')
     assert value_list == ['EEE', 'EE', 'E', ]
+
+
+def test_change_zorder_while_inactive():
+    from asyncpygame._api_impl.priority_drawing import Drawer, DrawingRequest
+
+    d = Drawer()
+    value_list = []
+
+    req = DrawingRequest(d.add_request, value_list.append, zorder=0)
+    DrawingRequest(d.add_request, lambda v: value_list.append(v.lower()), zorder=1)
+    d.draw('A')
+    assert value_list == ['A', 'a']
+    req.active = False
+    d.draw('B')
+    assert value_list == ['A', 'a', 'b']
+    req.zorder = 2
+    d.draw('C')
+    assert value_list == ['A', 'a', 'b', 'c']
+    req.active = True
+    d.draw('D')
+    assert value_list == ['A', 'a', 'b', 'c', 'd', 'D']