docs

src/textual/screen.py

@@ -184,10 +184,6 @@ class Screen(Widget):
         self._layout_required = True
         self.check_idle()
 
-    def on_mount(self, event: events.Mount) -> None:
-        pass
-        # self._refresh_layout()
-
     def _screen_resized(self, size: Size):
         """Called by App when the screen is resized."""
         self._refresh_layout(size, full=True)

src/textual/widget.py

@@ -122,6 +122,14 @@ class Widget(DOMNode):
     show_horizontal_scrollbar = Reactive(False, layout=True)
 
     def _arrange(self, size: Size) -> ArrangeResult:
+        """Arrange children.
+
+        Args:
+            size (Size): Size of container.
+
+        Returns:
+            ArrangeResult: Widget locations.
+        """
         arrange_cache_key = (self.children._updates, size)
         if (
             self._arrangement is not None