From 547b8531a15942fbf9d234be8b2163fb83e53727 Mon Sep 17 00:00:00 2001
From: Will McGugan <willmcgugan@gmail.com>
Date: Fri, 29 Jul 2022 10:51:37 +0100
Subject: [PATCH] optimization

---
 src/textual/_arrange.py       | 19 +++++++++++--------
 src/textual/css/stylesheet.py |  4 ----
 src/textual/widget.py         | 12 +++++-------
 3 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/src/textual/_arrange.py b/src/textual/_arrange.py
index 7922f0843..8b8b72476 100644
--- a/src/textual/_arrange.py
+++ b/src/textual/_arrange.py
@@ -2,7 +2,8 @@ from __future__ import annotations
 
 
 from fractions import Fraction
-from typing import TYPE_CHECKING
+from operator import attrgetter
+from typing import Sequence, TYPE_CHECKING
 
 from .geometry import Region, Size, Spacing
 from ._layout import DockArrangeResult, WidgetPlacement
@@ -13,7 +14,9 @@ if TYPE_CHECKING:
     from .widget import Widget
 
 
-def arrange(widget: Widget, size: Size, viewport: Size) -> DockArrangeResult:
+def arrange(
+    widget: Widget, children: Sequence[Widget], size: Size, viewport: Size
+) -> DockArrangeResult:
     """Arrange widgets by applying docks and calling layouts
 
     Args:
@@ -24,13 +27,14 @@ def arrange(widget: Widget, size: Size, viewport: Size) -> DockArrangeResult:
     Returns:
         tuple[list[WidgetPlacement], set[Widget], Spacing]: Widget arrangement information.
     """
-    display_children = [child for child in widget.children if child.display]
+    display_children = [child for child in children if child.display]
 
     arrange_widgets: set[Widget] = set()
 
     dock_layers: dict[str, list[Widget]] = {}
+    dock_layers_setdefault = dock_layers.setdefault
     for child in display_children:
-        dock_layers.setdefault(child.styles.layer or "default", []).append(child)
+        dock_layers_setdefault(child.styles.layer or "default", []).append(child)
 
     width, height = size
 
@@ -45,12 +49,11 @@ def arrange(widget: Widget, size: Size, viewport: Size) -> DockArrangeResult:
 
     scroll_spacing = Spacing()
 
+    get_dock = attrgetter("styles.dock")
+
     for widgets in dock_layers.values():
 
-        layout_widgets, dock_widgets = partition(
-            (lambda widget: widget.styles.dock), widgets
-        )
-
+        layout_widgets, dock_widgets = partition(get_dock, widgets)
         arrange_widgets.update(dock_widgets)
         top = right = bottom = left = 0
 
diff --git a/src/textual/css/stylesheet.py b/src/textual/css/stylesheet.py
index 156409c3d..ffc77557c 100644
--- a/src/textual/css/stylesheet.py
+++ b/src/textual/css/stylesheet.py
@@ -405,12 +405,8 @@ class Stylesheet:
         else:
             # Not animated, so we apply the rules directly
             get_rule = rules.get
-            from ..screen import Screen
 
             for key in modified_rule_keys:
-                if isinstance(node, Screen):
-
-                    print(node, key, get_rule(key))
                 setattr(base_styles, key, get_rule(key))
 
         node.post_message_no_wait(messages.StylesUpdated(sender=node))
diff --git a/src/textual/widget.py b/src/textual/widget.py
index e947b1171..2555f1121 100644
--- a/src/textual/widget.py
+++ b/src/textual/widget.py
@@ -10,7 +10,6 @@ from typing import (
     Collection,
     Iterable,
     NamedTuple,
-    Tuple,
 )
 
 import rich.repr
@@ -25,7 +24,7 @@ from rich.text import Text
 
 from . import errors, events, messages
 from ._animator import BoundAnimator
-from ._arrange import arrange
+from ._arrange import arrange, DockArrangeResult
 from ._context import active_app
 from ._layout import ArrangeResult, Layout
 from ._segment_tools import line_crop
@@ -115,7 +114,7 @@ class Widget(DOMNode):
         self._content_width_cache: tuple[object, int] = (None, 0)
         self._content_height_cache: tuple[object, int] = (None, 0)
 
-        self._arrangement: Tuple[ArrangeResult, Spacing] | None = None
+        self._arrangement: DockArrangeResult | None = None
         self._arrangement_cache_key: tuple[int, Size] = (-1, Size())
 
         self._styles_cache = StylesCache()
@@ -136,7 +135,7 @@ class Widget(DOMNode):
     show_vertical_scrollbar = Reactive(False, layout=True)
     show_horizontal_scrollbar = Reactive(False, layout=True)
 
-    def _arrange(self, size: Size) -> ArrangeResult:
+    def _arrange(self, size: Size) -> DockArrangeResult:
         """Arrange children.
 
         Args:
@@ -152,10 +151,9 @@ class Widget(DOMNode):
             and arrange_cache_key == self._arrangement_cache_key
         ):
             return self._arrangement
-        self._arrangement_cache_key = (self.children._updates, size)
-
-        self._arrangement = arrange(self, size, self.screen.size)
 
+        self._arrangement_cache_key = arrange_cache_key
+        self._arrangement = arrange(self, self.children, size, self.screen.size)
         return self._arrangement
 
     def _clear_arrangement_cache(self) -> None: