narrow down rules

docs/examples/introduction/stopwatch.css

@@ -52,3 +52,6 @@ Button {
     visibility: hidden
 }
 
+/* #timers:hover {
+    background: blue;
+} */

docs/examples/introduction/stopwatch.py

@@ -88,6 +88,7 @@ class StopwatchApp(App):
         new_stopwatch = Stopwatch()
         self.query_one("#timers").mount(new_stopwatch)
         new_stopwatch.scroll_visible()
+        self.sub_title = str(len(self.query("Stopwatch")))
 
     def action_remove_stopwatch(self) -> None:
         """Called to remove a timer."""

src/textual/_compositor.py

@@ -487,9 +487,8 @@ class Compositor:
         """Get the widget under the given point or None."""
         # TODO: Optimize with some line based lookup
         contains = Region.contains
-        is_visible = self.visible_widgets.__contains__
         for widget, cropped_region, region, *_ in self:
-            if is_visible(widget) and contains(cropped_region, x, y):
+            if contains(cropped_region, x, y):
                 return widget, region
         raise errors.NoWidget(f"No widget under screen coordinate ({x}, {y})")
 

src/textual/app.py

@@ -224,7 +224,7 @@ class App(Generic[ReturnType], DOMNode):
         self.design = DEFAULT_COLORS
 
         self.stylesheet = Stylesheet(variables=self.get_css_variables())
-        self._require_stylesheet_update = False
+        self._require_stylesheet_update: set[DOMNode] = set()
         self.css_path = css_path or self.CSS_PATH
 
         self._registry: WeakSet[DOMNode] = WeakSet()
@@ -720,15 +720,13 @@ class App(Generic[ReturnType], DOMNode):
         Should be called whenever CSS classes / pseudo classes change.
 
         """
-        if node is None:
-            self._require_stylesheet_update = True
-            self.check_idle()
-        else:
-            self.stylesheet.update(node, animate=True)
+        self._require_stylesheet_update.add(self.screen if node is None else node)
+        self.check_idle()
 
     def update_visible_styles(self) -> None:
         """Update visible styles only."""
-        self.stylesheet.update_nodes(self.screen.visible_widgets)
+        self._require_stylesheet_update.update(self.screen.visible_widgets)
+        self.check_idle()
 
     def mount(self, *anon_widgets: Widget, **widgets: Widget) -> None:
         """Mount widgets. Widgets specified as positional args, or keywords args. If supplied
@@ -1144,16 +1142,21 @@ class App(Generic[ReturnType], DOMNode):
 
         self.set_timer(screenshot_timer, on_screenshot, name="screenshot timer")
 
-    def on_mount(self) -> None:
+    def _on_mount(self) -> None:
         widgets = self.compose()
         if widgets:
             self.mount_all(widgets)
 
-    async def on_idle(self) -> None:
+    def _on_idle(self) -> None:
         """Perform actions when there are no messages in the queue."""
         if self._require_stylesheet_update:
-            self._require_stylesheet_update = False
-            self.stylesheet.update(self, animate=True)
+            nodes: set[DOMNode] = {
+                child
+                for node in self._require_stylesheet_update
+                for child in node.walk_children()
+            }
+            self._require_stylesheet_update.clear()
+            self.stylesheet.update_nodes(nodes, animate=True)
 
     def _register_child(self, parent: DOMNode, child: Widget) -> bool:
         if child not in self._registry:

src/textual/css/model.py

@@ -160,11 +160,13 @@ class RuleSet:
     styles: Styles = field(default_factory=Styles)
     errors: list[tuple[Token, str]] = field(default_factory=list)
 
-    ids: set[str] = field(default_factory=set)
     is_default_rules: bool = False
     tie_breaker: int = 0
     selector_names: set[str] = field(default_factory=set)
 
+    def __hash__(self):
+        return id(self)
+
     @classmethod
     def _selector_to_css(cls, selectors: list[Selector]) -> str:
         tokens: list[str] = []
@@ -200,10 +202,22 @@ class RuleSet:
 
         class_type = SelectorType.CLASS
         id_type = SelectorType.ID
+        type_type = SelectorType.TYPE
+        universal_type = SelectorType.UNIVERSAL
 
         update_selectors = self.selector_names.update
 
         for selector_set in self.selector_set:
+            update_selectors(
+                "*"
+                for selector in selector_set.selectors
+                if selector.type == universal_type
+            )
+            update_selectors(
+                selector.name
+                for selector in selector_set.selectors
+                if selector.type == type_type
+            )
             update_selectors(
                 f".{selector.name}"
                 for selector in selector_set.selectors

src/textual/css/stylesheet.py

@@ -312,7 +312,13 @@ class Stylesheet:
             if _check_selectors(selector_set.selectors, css_path_nodes):
                 yield selector_set.specificity
 
-    def apply(self, node: DOMNode, animate: bool = False) -> None:
+    def apply(
+        self,
+        node: DOMNode,
+        *,
+        limit_rules: set[RuleSet] | None = None,
+        animate: bool = False,
+    ) -> None:
         """Apply the stylesheet to a DOM node.
 
         Args:
@@ -334,12 +340,18 @@ class Stylesheet:
         _check_rule = self._check_rule
 
         css_path_nodes = node.css_path_nodes
+
         selector_names = {
             selector for node in css_path_nodes for selector in node._selector_names
         }
 
+        rules: Iterable[RuleSet]
+        if limit_rules:
+            rules = [rule for rule in reversed(self.rules) if rule in limit_rules]
+        else:
+            rules = reversed(self.rules)
         # Collect the rules defined in the stylesheet
-        for rule in reversed(self.rules):
+        for rule in rules:
             if rule.selector_names and not rule.selector_names.issubset(selector_names):
                 continue
 
@@ -457,10 +469,17 @@ class Stylesheet:
             nodes (DOMNode): Nodes to update.
             animate (bool, optional): Enable CSS animation. Defaults to False.
         """
+
+        rules_map: defaultdict[str, list[RuleSet]] = defaultdict(list)
+        for rule in self.rules:
+            for name in rule.selector_names:
+                rules_map[name].append(rule)
+
         apply = self.apply
-        nodes = list(nodes)
+
         for node in nodes:
-            apply(node, animate=animate)
+            rules = {rule for name in node._selector_names for rule in rules_map[name]}
+            apply(node, limit_rules=rules, animate=animate)
             if isinstance(node, Widget) and node.is_scrollable:
                 if node.show_vertical_scrollbar:
                     apply(node.vertical_scrollbar)

src/textual/dom.py

@@ -320,6 +320,7 @@ class DOMNode(MessagePump):
             set[str]: Set of selector names.
         """
         selectors: list[str] = [
+            "*",
             *(f".{class_name}" for class_name in self._classes),
             *(f":{class_name}" for class_name in self.get_pseudo_classes()),
             *self._css_types,
@@ -716,7 +717,7 @@ class DOMNode(MessagePump):
         if old_classes == self._classes:
             return
         try:
-            self.app.stylesheet.update(self, animate=True)
+            self.app.update_styles(self)
         except NoActiveAppError:
             pass
 
@@ -732,7 +733,7 @@ class DOMNode(MessagePump):
         if old_classes == self._classes:
             return
         try:
-            self.app.stylesheet.update(self, animate=True)
+            self.app.update_styles(self)
         except NoActiveAppError:
             pass
 
@@ -748,7 +749,7 @@ class DOMNode(MessagePump):
         if old_classes == self._classes:
             return
         try:
-            self.app.stylesheet.update(self, animate=True)
+            self.app.update_styles(self)
         except NoActiveAppError:
             pass