List: inherit from GroupedLabeledFlowables

- adjust the docutils frontend to this change
- determine list item indices dynamically

src/rinoh/frontend/rst/nodes.py

@@ -471,25 +471,29 @@ def build_flowable(self):
         return rt.AnchorFlowable()
 
 
-class Enumerated_List(DocutilsBodyNode):
+class Enumerated_List(DocutilsGroupingNode):
+    style = 'enumerated'
+    grouped_flowables_class = rt.List
+
     def build_flowable(self):
         # TODO: handle different numbering styles
         start = self.attributes.get('start', 1)
-        return rt.List([item.flowable() for item in self.list_item],
-                       start_index=start, style='enumerated')
+        return super().build_flowable(start_index=start)
 
+class Bullet_List(DocutilsGroupingNode):
+    style = 'bulleted'
+    grouped_flowables_class = rt.List
 
-class Bullet_List(DocutilsBodyNode):
     def build_flowable(self):
         try:
-            return rt.List([item.flowable() for item in self.list_item],
-                           style='bulleted')
+            return super().build_flowable()
         except AttributeError:  # empty list
             return rt.DummyFlowable()
 
 
 class List_Item(DocutilsGroupingNode):
-    pass
+    def build_flowable(self):
+        return rt.ListItem(super().build_flowable())
 
 
 class Definition_List(DocutilsGroupingNode):

src/rinoh/structure.py

@@ -185,19 +185,18 @@ class ListStyle(GroupedFlowablesStyle, NumberStyle):
                        'Bullet to use in unordered lists')
 
 
-class List(StaticGroupedFlowables, Label):
+class List(GroupedLabeledFlowables, StaticGroupedFlowables):
     style_class = ListStyle
 
-    def __init__(self, flowables, start_index=1,
+    def __init__(self, list_items, start_index=1,
                  id=None, style=None, parent=None):
-        items = [ListItem(i, flowable, parent=self)
-                 for i, flowable in enumerate(flowables, start_index)]
-        super().__init__(items, id=id, style=style, parent=parent)
+        super().__init__(list_items, id=id, style=style, parent=parent)
+        self.start_index = start_index
 
 
 class ListItem(LabeledFlowable):
-    def __init__(self, index, flowable, id=None, style=None, parent=None):
-        label = ListItemLabel(index)
+    def __init__(self, flowable, id=None, style=None, parent=None):
+        label = ListItemLabel()
         super().__init__(label, flowable, id=id, style=style, parent=parent)
 
 
@@ -208,15 +207,13 @@ class ListItemLabelStyle(ParagraphStyle, LabelStyle):
 class ListItemLabel(ParagraphBase, Label):
     style_class = ListItemLabelStyle
 
-    def __init__(self, index, style=None, parent=None):
-        super().__init__(style=style, parent=parent)
-        self.index = index
-
     def text(self, container):
-        list = self.parent.parent
+        list_item = self.parent
+        list = list_item.parent
         if list.get_style('ordered', container):
+            index = list.start_index + list.children.index(list_item)
             number_format = list.get_style('number_format', container)
-            label = format_number(self.index, number_format)
+            label = format_number(index, number_format)
         else:
             label = list.get_style('bullet', container)
         return MixedStyledText(self.format_label(label, container), parent=self)