optimization (#3970)

* optimization

* fix

* changelog [skip ci]

* sort

* simplification

* simplify check

* fix and typing

* typing

* docstrings

* Apply suggestions from code review

Co-authored-by: Rodrigo Girão Serrão <[email protected]>

* Update src/textual/dom.py

Co-authored-by: Rodrigo Girão Serrão <[email protected]>

---------

Co-authored-by: Rodrigo Girão Serrão <[email protected]>

CHANGELOG.md

@@ -7,10 +7,19 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Changed
+
+- Breaking change: `DOMNode.has_pseudo_class` now accepts a single name only https://github.com/Textualize/textual/pull/3970
+
+### Added
+
+- Added `DOMNode.has_pseudo_classes` https://github.com/Textualize/textual/pull/3970
+
 ### Fixed
 
 - Parameter `animate` from `DataTable.move_cursor` was being ignored https://github.com/Textualize/textual/issues/3840
 
+
 ## [0.47.1] - 2023-01-05
 
 ### Fixed

src/textual/css/model.py

@@ -2,6 +2,7 @@
 
 from dataclasses import dataclass, field
 from enum import Enum
+from functools import partial
 from typing import TYPE_CHECKING, Iterable
 
 import rich.repr
@@ -12,6 +13,8 @@
 from .types import Specificity3
 
 if TYPE_CHECKING:
+    from typing import Callable
+
     from typing_extensions import Self
 
     from ..dom import DOMNode
@@ -43,6 +46,67 @@ class CombinatorType(Enum):
     """Selector is an immediate child of the previous selector"""
 
 
+def _check_universal(name: str, node: DOMNode) -> bool:
+    """Check node matches universal selector.
+
+    Args:
+        name: Selector name.
+        node: A DOM node.
+
+    Returns:
+        `True` if the selector matches.
+    """
+    return True
+
+
+def _check_type(name: str, node: DOMNode) -> bool:
+    """Check node matches a type selector.
+
+    Args:
+        name: Selector name.
+        node: A DOM node.
+
+    Returns:
+        `True` if the selector matches.
+    """
+    return name in node._css_type_names
+
+
+def _check_class(name: str, node: DOMNode) -> bool:
+    """Check node matches a class selector.
+
+    Args:
+        name: Selector name.
+        node: A DOM node.
+
+    Returns:
+        `True` if the selector matches.
+    """
+    return name in node._classes
+
+
+def _check_id(name: str, node: DOMNode) -> bool:
+    """Check node matches an ID selector.
+
+    Args:
+        name: Selector name.
+        node: A DOM node.
+
+    Returns:
+        `True` if the selector matches.
+    """
+    return node.id == name
+
+
+_CHECKS = {
+    SelectorType.UNIVERSAL: _check_universal,
+    SelectorType.TYPE: _check_type,
+    SelectorType.CLASS: _check_class,
+    SelectorType.ID: _check_id,
+    SelectorType.NESTED: _check_universal,
+}
+
+
 @dataclass
 class Selector:
     """Represents a CSS selector.
@@ -57,14 +121,17 @@ class Selector:
     name: str
     combinator: CombinatorType = CombinatorType.DESCENDENT
     type: SelectorType = SelectorType.TYPE
-    pseudo_classes: list[str] = field(default_factory=list)
+    pseudo_classes: set[str] = field(default_factory=set)
     specificity: Specificity3 = field(default_factory=lambda: (0, 0, 0))
     advance: int = 1
 
+    def __post_init__(self) -> None:
+        self._check: Callable[[DOMNode], bool] = partial(_CHECKS[self.type], self.name)
+
     @property
     def css(self) -> str:
         """Rebuilds the selector as it would appear in CSS."""
-        pseudo_suffix = "".join(f":{name}" for name in self.pseudo_classes)
+        pseudo_suffix = "".join(f":{name}" for name in sorted(self.pseudo_classes))
         if self.type == SelectorType.UNIVERSAL:
             return "*"
         elif self.type == SelectorType.TYPE:
@@ -74,21 +141,13 @@ def css(self) -> str:
         else:
             return f"#{self.name}{pseudo_suffix}"
 
-    def __post_init__(self) -> None:
-        self._checks = {
-            SelectorType.UNIVERSAL: self._check_universal,
-            SelectorType.TYPE: self._check_type,
-            SelectorType.CLASS: self._check_class,
-            SelectorType.ID: self._check_id,
-        }
-
     def _add_pseudo_class(self, pseudo_class: str) -> None:
         """Adds a pseudo class and updates specificity.
 
         Args:
             pseudo_class: Name of pseudo class.
         """
-        self.pseudo_classes.append(pseudo_class)
+        self.pseudo_classes.add(pseudo_class)
         specificity1, specificity2, specificity3 = self.specificity
         self.specificity = (specificity1, specificity2 + 1, specificity3)
 
@@ -101,31 +160,11 @@ def check(self, node: DOMNode) -> bool:
         Returns:
             True if the selector matches, otherwise False.
         """
-        return self._checks[self.type](node)
-
-    def _check_universal(self, node: DOMNode) -> bool:
-        return node.has_pseudo_class(*self.pseudo_classes)
-
-    def _check_type(self, node: DOMNode) -> bool:
-        if self.name not in node._css_type_names:
-            return False
-        if self.pseudo_classes and not node.has_pseudo_class(*self.pseudo_classes):
-            return False
-        return True
-
-    def _check_class(self, node: DOMNode) -> bool:
-        if not node.has_class(self.name):
-            return False
-        if self.pseudo_classes and not node.has_pseudo_class(*self.pseudo_classes):
-            return False
-        return True
-
-    def _check_id(self, node: DOMNode) -> bool:
-        if node.id != self.name:
-            return False
-        if self.pseudo_classes and not node.has_pseudo_class(*self.pseudo_classes):
-            return False
-        return True
+        return self._check(node) and (
+            node.has_pseudo_classes(self.pseudo_classes)
+            if self.pseudo_classes
+            else True
+        )
 
 
 @dataclass

src/textual/css/parse.py

@@ -208,11 +208,9 @@ def combine_selectors(
                     nested_selector = selectors2[0]
                     merged_selector = dataclasses.replace(
                         final_selector,
-                        pseudo_classes=list(
-                            set(
-                                final_selector.pseudo_classes
-                                + nested_selector.pseudo_classes
-                            )
+                        pseudo_classes=(
+                            final_selector.pseudo_classes
+                            | nested_selector.pseudo_classes
                         ),
                         specificity=_add_specificity(
                             final_selector.specificity, nested_selector.specificity

src/textual/css/stylesheet.py

@@ -30,6 +30,8 @@
 
 
 class StylesheetParseError(StylesheetError):
+    """Raised when the stylesheet could not be parsed."""
+
     def __init__(self, errors: StylesheetErrors) -> None:
         self.errors = errors
 
@@ -38,6 +40,8 @@ def __rich__(self) -> RenderableType:
 
 
 class StylesheetErrors:
+    """A renderable for stylesheet errors."""
+
     def __init__(self, rules: list[RuleSet]) -> None:
         self.rules = rules
         self.variables: dict[str, str] = {}
@@ -134,6 +138,8 @@ class CssSource(NamedTuple):
 
 @rich.repr.auto(angular=True)
 class Stylesheet:
+    """A Stylsheet generated from Textual CSS."""
+
     def __init__(self, *, variables: dict[str, str] | None = None) -> None:
         self._rules: list[RuleSet] = []
         self._rules_map: dict[str, list[RuleSet]] | None = None
@@ -183,6 +189,10 @@ def rules_map(self) -> dict[str, list[RuleSet]]:
 
     @property
     def css(self) -> str:
+        """The equivalent TCSS for this stylesheet.
+
+        Note that this may not produce the same content as the file(s) used to generate the stylesheet.
+        """
         return "\n\n".join(rule_set.css for rule_set in self.rules)
 
     def copy(self) -> Stylesheet:
@@ -407,9 +417,18 @@ def reparse(self) -> None:
 
     @classmethod
     def _check_rule(
-        cls, rule: RuleSet, css_path_nodes: list[DOMNode]
+        cls, rule_set: RuleSet, css_path_nodes: list[DOMNode]
     ) -> Iterable[Specificity3]:
-        for selector_set in rule.selector_set:
+        """Check a rule set, return specificity of applicable rules.
+
+        Args:
+            rule_set: A rule set.
+            css_path_nodes: A list of the nodes from the App to the node being checked.
+
+        Yields:
+            Specificity of any matching selectors.
+        """
+        for selector_set in rule_set.selector_set:
             if _check_selectors(selector_set.selectors, css_path_nodes):
                 yield selector_set.specificity
 

src/textual/dom.py

@@ -166,7 +166,7 @@ def __init__(
         id: str | None = None,
         classes: str | None = None,
     ) -> None:
-        self._classes = set()
+        self._classes: set[str] = set()
         self._name = name
         self._id = None
         if id is not None:
@@ -575,8 +575,7 @@ def css_identifier_styled(self) -> Text:
     @property
     def pseudo_classes(self) -> frozenset[str]:
         """A (frozen) set of all pseudo classes."""
-        pseudo_classes = frozenset(self.get_pseudo_classes())
-        return pseudo_classes
+        return frozenset(self.get_pseudo_classes())
 
     @property
     def css_path_nodes(self) -> list[DOMNode]:
@@ -1276,17 +1275,27 @@ def toggle_class(self, *class_names: str) -> Self:
         self._update_styles()
         return self
 
-    def has_pseudo_class(self, *class_names: str) -> bool:
-        """Check for pseudo classes (such as hover, focus etc)
+    def has_pseudo_class(self, class_name: str) -> bool:
+        """Check the node has the given pseudo class.
 
         Args:
-            *class_names: The pseudo classes to check for.
+            class_name: The pseudo class to check for.
 
         Returns:
-            `True` if the DOM node has those pseudo classes, `False` if not.
+            `True` if the DOM node has the pseudo class, `False` if not.
         """
-        has_pseudo_classes = self.pseudo_classes.issuperset(class_names)
-        return has_pseudo_classes
+        return class_name in self.get_pseudo_classes()
+
+    def has_pseudo_classes(self, class_names: set[str]) -> bool:
+        """Check the node has all the given pseudo classes.
+
+        Args:
+            class_names: Set of class names to check for.
+
+        Returns:
+            `True` if all pseudo class names are present.
+        """
+        return class_names.issubset(self.get_pseudo_classes())
 
     def refresh(self, *, repaint: bool = True, layout: bool = False) -> Self:
         return self

src/textual/widget.py

@@ -2876,14 +2876,6 @@ def get_pseudo_classes(self) -> Iterable[str]:
         Returns:
             Names of the pseudo classes.
         """
-        node: MessagePump | None = self
-        while isinstance(node, Widget):
-            if node.disabled:
-                yield "disabled"
-                break
-            node = node._parent
-        else:
-            yield "enabled"
         if self.mouse_over:
             yield "hover"
         if self.has_focus:
@@ -2892,6 +2884,14 @@ def get_pseudo_classes(self) -> Iterable[str]:
             yield "blur"
         if self.can_focus:
             yield "can-focus"
+        node: MessagePump | None = self
+        while isinstance(node, Widget):
+            if node.disabled:
+                yield "disabled"
+                break
+            node = node._parent
+        else:
+            yield "enabled"
         try:
             focused = self.screen.focused
         except NoScreen: