sort menu items

raven/plugins/domain/menucontribution.py

@@ -1,11 +1,51 @@
 from raven.plugins.domain.raction import RAction
 from raven.plugins.domain.rmenu import RMenu
 
+id_counter = 0
+
+
+def next_id() -> str:
+    global id_counter
+    id_counter = id_counter + 1
+    return "action_%d" % id_counter
+
 
 class MenuContribution():
-    def __init__(self, menu_id: str, action: RAction = None, menu: RMenu = None, action_id=None):
+    def __init__(self,
+                 menu_id: str,
+                 action: RAction = None,
+                 menu: RMenu = None,
+                 action_id=None,
+                 after=None):
         super(MenuContribution, self).__init__()
         self.menu_id = menu_id
         self.action = action
         self.menu = menu
-        self.action_id = action_id
+        self.action_id = action_id if action_id else next_id()
+        self.after = after
+
+
+def _sort_by_action_id(menu_contributions: [MenuContribution]) -> [MenuContribution]:
+    return sorted(menu_contributions, key=lambda mc: mc.action_id)
+
+
+def sort_menu_contributions(menu_contributions: [MenuContribution]) -> [MenuContribution]:
+    result = []
+    items = _sort_by_action_id(menu_contributions[:])
+
+    _recursive_half_order_adder(result, items, None)
+
+    # add remaining items to the end (ordered by their action_id)
+    # This resolves cycles.
+    for item in items:
+        result.append(item)
+    return result
+
+
+def _recursive_half_order_adder(result: [MenuContribution], items: [MenuContribution], parent):
+    for item in items:
+        mc: MenuContribution = item
+        if not mc.after:
+            result.append(mc)
+            items.remove(mc)
+            _recursive_half_order_adder(result, items, mc.action_id)