fixed focus-within

Author: willmcgugan

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+- Fixed broken focus-within https://github.com/Textualize/textual/issues/5184
+
 ## [0.85.1] - 2024-10-26
 
 ### Fixed

src/textual/app.py

@@ -762,8 +762,8 @@ def __init__(
         perform work after the app has resumed.
         """
 
-        self.set_class(self.dark, "-dark-mode")
-        self.set_class(not self.dark, "-light-mode")
+        self.set_class(self.dark, "-dark-mode", update=False)
+        self.set_class(not self.dark, "-light-mode", update=False)
 
         self.animation_level: AnimationLevel = constants.TEXTUAL_ANIMATIONS
         """Determines what type of animations the app will display.

src/textual/css/stylesheet.py

@@ -433,13 +433,14 @@ def _check_rule(
             if _check_selectors(selector_set.selectors, css_path_nodes):
                 yield selector_set.specificity
 
-    # pseudo classes which iterate over many nodes
-    # these have the potential to be slow, and shouldn't be used in a cache key
-    EXPENSIVE_PSEUDO_CLASSES = {
+    # pseudo classes which iterate over multiple nodes
+    # These shouldn't be used in a cache key
+    EXCLUDE_PSEUDO_CLASSES = {
         "first-of-type",
         "last-of_type",
         "odd",
         "even",
+        "focus-within",
     }
 
     def apply(
@@ -487,7 +488,7 @@ def apply(
         cache_key: tuple | None = None
 
         if cache is not None and all_pseudo_classes.isdisjoint(
-            self.EXPENSIVE_PSEUDO_CLASSES
+            self.EXCLUDE_PSEUDO_CLASSES
         ):
             cache_key = (
                 node._parent,

src/textual/widgets/_button.py

@@ -210,6 +210,8 @@ def __init__(
 
         self.label = label
         self.variant = variant
+        self.set_reactive(Button.variant, variant)
+        self.add_class(f"-{variant}", update=False)
         self.action = action
         self.active_effect_duration = 0.2
         """Amount of time in seconds the button 'press' animation lasts."""