simplified cache_key

CHANGELOG.md

@@ -33,6 +33,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Watchers are now called immediately when setting the attribute if they are synchronous. https://github.com/Textualize/textual/pull/1145
 - Widget.call_later has been renamed to Widget.call_after_refresh.
 - Button variant values are now checked at runtime. https://github.com/Textualize/textual/issues/1189
+- Added caching of some properties in Styles object
 
 ### Fixed
 

src/textual/css/styles.py

@@ -557,6 +557,7 @@ class StylesBase(ABC):
 class Styles(StylesBase):
     node: DOMNode | None = None
     _rules: RulesMap = field(default_factory=dict)
+    _updates: int = 0
 
     important: set[str] = field(default_factory=set)
 
@@ -577,6 +578,7 @@ class Styles(StylesBase):
         Returns:
             bool: ``True`` if a rule was cleared, or ``False`` if it was already not set.
         """
+        self._updates += 1
         return self._rules.pop(rule, None) is not None
 
     def get_rules(self) -> RulesMap:
@@ -592,6 +594,7 @@ class Styles(StylesBase):
         Returns:
             bool: ``True`` if the rule changed, otherwise ``False``.
         """
+        self._updates += 1
         if value is None:
             return self._rules.pop(rule, None) is not None
         current = self._rules.get(rule)
@@ -610,6 +613,7 @@ class Styles(StylesBase):
 
     def reset(self) -> None:
         """Reset the rules to initial state."""
+        self._updates += 1
         self._rules.clear()
 
     def merge(self, other: Styles) -> None:
@@ -618,10 +622,11 @@ class Styles(StylesBase):
         Args:
             other (Styles): A Styles object.
         """
-
+        self._updates += 1
         self._rules.update(other._rules)
 
     def merge_rules(self, rules: RulesMap) -> None:
+        self._updates += 1
         self._rules.update(rules)
 
     def extract_rules(
@@ -929,6 +934,18 @@ class RenderStyles(StylesBase):
         self._base_styles = base
         self._inline_styles = inline_styles
         self._animate: BoundAnimator | None = None
+        self._updates: int = 0
+        self._rich_style: tuple[int, Style] | None = None
+        self._gutter: tuple[int, Spacing] | None = None
+
+    @property
+    def _cache_key(self) -> int:
+        """A key key, that changes when any style is changed.
+
+        Returns:
+            int: An opaque integer.
+        """
+        return self._updates + self._base_styles._updates + self._inline_styles._updates
 
     @property
     def base(self) -> Styles:
@@ -946,6 +963,21 @@ class RenderStyles(StylesBase):
         assert self.node is not None
         return self.node.rich_style
 
+    @property
+    def gutter(self) -> Spacing:
+        """Get space around widget.
+
+        Returns:
+            Spacing: Space around widget content.
+        """
+        if self._gutter is not None:
+            cache_key, gutter = self._gutter
+            if cache_key == self._updates:
+                return gutter
+        gutter = self.padding + self.border.spacing
+        self._gutter = (self._cache_key, gutter)
+        return gutter
+
     def animate(
         self,
         attribute: str,
@@ -972,6 +1004,7 @@ class RenderStyles(StylesBase):
 
         """
         if self._animate is None:
+            assert self.node is not None
             self._animate = self.node.app.animator.bind(self)
         assert self._animate is not None
         self._animate(
@@ -1003,16 +1036,19 @@ class RenderStyles(StylesBase):
 
     def merge_rules(self, rules: RulesMap) -> None:
         self._inline_styles.merge_rules(rules)
+        self._updates += 1
 
     def reset(self) -> None:
         """Reset the rules to initial state."""
         self._inline_styles.reset()
+        self._updates += 1
 
     def has_rule(self, rule: str) -> bool:
         """Check if a rule has been set."""
         return self._inline_styles.has_rule(rule) or self._base_styles.has_rule(rule)
 
     def set_rule(self, rule: str, value: object | None) -> bool:
+        self._updates += 1
         return self._inline_styles.set_rule(rule, value)
 
     def get_rule(self, rule: str, default: object = None) -> object:
@@ -1022,6 +1058,7 @@ class RenderStyles(StylesBase):
 
     def clear_rule(self, rule_name: str) -> bool:
         """Clear a rule (from inline)."""
+        self._updates += 1
         return self._inline_styles.clear_rule(rule_name)
 
     def get_rules(self) -> RulesMap: