Refactor conversation rendering into mixin for reuse

tt

@@ -21,30 +21,18 @@ manager = twtxtmanager.TwtxtManager(config)
 manager.load_twts()
 renderer = twtxtrenderer.Renderer(config)
 
-class TwtsListBox(widgets.VimListBox):
-    def __init__(self, manager, cmdline):
-        self._manager = manager
-        self._cmdline = cmdline
-        self._twts = []
-        self._search = None
-        self._search_downwards = True
-
-        items = []
-
-        def render(twt, level=0, indentation="", more_siblings=False):
-            widget, next_indentation = self.format_twt(twt, level, indentation, more_siblings)
-            items.append(widget)
-            self._twts.append(twt)
-            for i, reply in enumerate(twt.replies):
-                render(reply, level=level + 1, indentation=next_indentation, more_siblings=i < len(twt.replies) - 1)
-
-        for twt in reversed(manager.conversation_tree):
-            render(twt)
+class TwtFormatter:
 
-        super().__init__(urwid.SimpleFocusListWalker(items))
+    def render_conversation(self, manager, twt, into_widgets, into_twts, level=0, indentation="", more_siblings=False):
+        widget, next_indentation = self.format_twt(manager, twt, level, indentation, more_siblings)
+        into_widgets.append(widget)
+        into_twts.append(twt)
+        for i, reply in enumerate(twt.replies):
+            self.render_conversation(manager, reply, into_widgets, into_twts, level=level + 1,
+                                     indentation=next_indentation, more_siblings=i < len(twt.replies) - 1)
 
 
-    def format_twt(self, twt, level, indentation, more_siblings):
+    def format_twt(self, manager, twt, level, indentation, more_siblings):
         created_at = "%s (%s)" % (twt.created_at.astimezone().strftime('%Y-%m-%d %H:%M'),
                                   twt.relative_datetime \
                                      .replace("seconds", "s") \
@@ -75,9 +63,9 @@ class TwtsListBox(widgets.VimListBox):
                 if token.nick:
                     nick = token.nick
                     url = token.url
-                    following = self._manager.is_following(nick, url)
+                    following = manager.is_following(nick, url)
                 elif token.url:
-                    nick = self._manager.resolve_nick_by_url_from_cache(token.url)
+                    nick = manager.resolve_nick_by_url_from_cache(token.url)
                     url = token.url
                     following = nick is not None
                 else:
@@ -149,13 +137,28 @@ class TwtsListBox(widgets.VimListBox):
 
         return (widgets.SelectableAttrMap(urwid.Columns(filter(lambda x: x, [
                 (28, urwid.Text(created_at)),
-                (self._manager.max_author_nick_width, urwid.Text(nick, align="right")),
+                (manager.max_author_nick_width, urwid.Text(nick, align="right")),
                 text]), dividechars=2),
                 renderer.read_normal_map if twt.read else renderer.unread_normal_map,
                 renderer.read_focus_map if twt.read else renderer.unread_focus_map),
                 next_indentation)
 
 
+class TwtsListBox(widgets.VimListBox, TwtFormatter):
+    def __init__(self, manager, cmdline):
+        self._manager = manager
+        self._cmdline = cmdline
+        self._twts = []
+        self._search = None
+        self._search_downwards = True
+
+        widgets = []
+        for twt in reversed(manager.conversation_tree):
+            self.render_conversation(manager, twt, widgets, self._twts)
+
+        super().__init__(urwid.SimpleFocusListWalker(widgets))
+
+
     def keypress(self, size, key):
         if key == "r":
             self.toggle_read()