Optimizations (#3837)

* optimize layout

* optimization

* test fix

* startup optimization

* simplify

* faster content height

src/textual/_callback.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import asyncio
-from functools import lru_cache
+from functools import lru_cache, partial
 from inspect import isawaitable, signature
 from typing import TYPE_CHECKING, Any, Callable
 
@@ -14,8 +14,19 @@
 INVOKE_TIMEOUT_WARNING = 3
 
 
-@lru_cache(maxsize=2048)
 def count_parameters(func: Callable) -> int:
+    """Count the number of parameters in a callable"""
+    if isinstance(func, partial):
+        return _count_parameters(func.func) + len(func.args)
+    if hasattr(func, "__self__"):
+        # Bound method
+        func = func.__func__  # type: ignore
+        return _count_parameters(func) - 1
+    return _count_parameters(func)
+
+
+@lru_cache(maxsize=2048)
+def _count_parameters(func: Callable) -> int:
     """Count the number of parameters in a callable"""
     return len(signature(func).parameters)
 

src/textual/app.py

@@ -829,8 +829,8 @@ def watch_dark(self, dark: bool) -> None:
         This method handles the transition between light and dark mode when you
         change the [dark][textual.app.App.dark] attribute.
         """
-        self.set_class(dark, "-dark-mode")
-        self.set_class(not dark, "-light-mode")
+        self.set_class(dark, "-dark-mode", update=False)
+        self.set_class(not dark, "-light-mode", update=False)
         self.call_later(self.refresh_css)
 
     def get_driver_class(self) -> Type[Driver]:
@@ -1586,7 +1586,6 @@ def update_styles(self, node: DOMNode) -> None:
         will be added, and this method is called to apply the corresponding
         :hover styles.
         """
-
         descendants = node.walk_children(with_self=True)
         self.stylesheet.update_nodes(descendants, animate=True)
 

src/textual/css/_style_properties.py

@@ -761,7 +761,7 @@ def __get__(self, obj: StylesBase, objtype: type[StylesBase] | None = None) -> s
         Returns:
             The string property value.
         """
-        return cast(str, obj.get_rule(self.name, self._default))
+        return obj.get_rule(self.name, self._default)  # type: ignore
 
     def _before_refresh(self, obj: StylesBase, value: str | None) -> None:
         """Do any housekeeping before asking for a layout refresh after a value change."""

src/textual/dom.py

@@ -1176,19 +1176,20 @@ def has_class(self, *class_names: str) -> bool:
         """
         return self._classes.issuperset(class_names)
 
-    def set_class(self, add: bool, *class_names: str) -> Self:
+    def set_class(self, add: bool, *class_names: str, update: bool = True) -> Self:
         """Add or remove class(es) based on a condition.
 
         Args:
             add: Add the classes if True, otherwise remove them.
+            update: Also update styles.
 
         Returns:
             Self.
         """
         if add:
-            self.add_class(*class_names)
+            self.add_class(*class_names, update=update)
         else:
-            self.remove_class(*class_names)
+            self.remove_class(*class_names, update=update)
         return self
 
     def set_classes(self, classes: str | Iterable[str]) -> Self:
@@ -1209,16 +1210,18 @@ def _update_styles(self) -> None:
 
         Should be called whenever CSS classes / pseudo classes change.
         """
-        try:
-            self.app.update_styles(self)
-        except NoActiveAppError:
-            pass
+        if self._is_mounted:
+            try:
+                self.app.update_styles(self)
+            except NoActiveAppError:
+                pass
 
-    def add_class(self, *class_names: str) -> Self:
+    def add_class(self, *class_names: str, update: bool = True) -> Self:
         """Add class names to this Node.
 
         Args:
             *class_names: CSS class names to add.
+            update: Also update styles.
 
         Returns:
             Self.
@@ -1228,14 +1231,16 @@ def add_class(self, *class_names: str) -> Self:
         self._classes.update(class_names)
         if old_classes == self._classes:
             return self
-        self._update_styles()
+        if update:
+            self._update_styles()
         return self
 
-    def remove_class(self, *class_names: str) -> Self:
+    def remove_class(self, *class_names: str, update: bool = True) -> Self:
         """Remove class names from this Node.
 
         Args:
             *class_names: CSS class names to remove.
+            update: Also update styles.
 
         Returns:
             Self.
@@ -1245,7 +1250,8 @@ def remove_class(self, *class_names: str) -> Self:
         self._classes.difference_update(class_names)
         if old_classes == self._classes:
             return self
-        self._update_styles()
+        if update:
+            self._update_styles()
         return self
 
     def toggle_class(self, *class_names: str) -> Self:

src/textual/layouts/horizontal.py

@@ -73,16 +73,26 @@ def arrange(
 
         _Region = Region
         _WidgetPlacement = WidgetPlacement
-        for widget, box_model, margin in zip(children, box_models, margins):
+        for widget, (content_width, content_height, box_margin), margin in zip(
+            children, box_models, margins
+        ):
             overlay = widget.styles.overlay == "screen"
-            content_width, content_height, box_margin = box_model
             offset_y = box_margin.top
             next_x = x + content_width
-            region = _Region(
-                int(x), offset_y, int(next_x - int(x)), int(content_height)
-            )
             add_placement(
-                _WidgetPlacement(region, box_model.margin, widget, 0, False, overlay)
+                _WidgetPlacement(
+                    _Region(
+                        int(x),
+                        offset_y,
+                        int(next_x - int(x)),
+                        int(content_height),
+                    ),
+                    box_margin,
+                    widget,
+                    0,
+                    False,
+                    overlay,
+                )
             )
             if not overlay:
                 x = next_x + margin

src/textual/layouts/vertical.py

@@ -73,17 +73,25 @@ def arrange(
 
         _Region = Region
         _WidgetPlacement = WidgetPlacement
-
-        for widget, box_model, margin in zip(children, box_models, margins):
+        for widget, (content_width, content_height, box_margin), margin in zip(
+            children, box_models, margins
+        ):
             overlay = widget.styles.overlay == "screen"
-            content_width, content_height, box_margin = box_model
             next_y = y + content_height
-
-            region = _Region(
-                box_margin.left, int(y), int(content_width), int(next_y) - int(y)
-            )
             add_placement(
-                _WidgetPlacement(region, box_model.margin, widget, 0, False, overlay)
+                _WidgetPlacement(
+                    _Region(
+                        box_margin.left,
+                        int(y),
+                        int(content_width),
+                        int(next_y) - int(y),
+                    ),
+                    box_margin,
+                    widget,
+                    0,
+                    False,
+                    overlay,
+                )
             )
             if not overlay:
                 y = next_y + margin

src/textual/widget.py

@@ -1180,10 +1180,22 @@ def get_content_height(self, container: Size, viewport: Size, width: int) -> int
                 return self._content_height_cache[1]
 
             renderable = self.render()
-            options = self._console.options.update_width(width).update(highlight=False)
-            segments = self._console.render(renderable, options)
-            # Cheaper than counting the lines returned from render_lines!
-            height = sum([text.count("\n") for text, _, _ in segments])
+            if isinstance(renderable, Text):
+                height = len(
+                    renderable.wrap(
+                        self._console,
+                        width,
+                        no_wrap=renderable.no_wrap,
+                        tab_size=renderable.tab_size or 8,
+                    )
+                )
+            else:
+                options = self._console.options.update_width(width).update(
+                    highlight=False
+                )
+                segments = self._console.render(renderable, options)
+                # Cheaper than counting the lines returned from render_lines!
+                height = sum([text.count("\n") for text, _, _ in segments])
             self._content_height_cache = (cache_key, height)
 
         return height

src/textual/widgets/_collapsible.py

@@ -199,7 +199,7 @@ def _update_collapsed(self, collapsed: bool) -> None:
         except NoMatches:
             pass
 
-    def _on_mount(self) -> None:
+    def _on_mount(self, event: events.Mount) -> None:
         """Initialise collapsed state."""
         self._update_collapsed(self.collapsed)
 

tests/test_arrange.py

@@ -2,6 +2,7 @@
 
 from textual._arrange import TOP_Z, arrange
 from textual._layout import WidgetPlacement
+from textual.app import App
 from textual.geometry import Region, Size, Spacing
 from textual.widget import Widget
 
@@ -16,6 +17,7 @@ def test_arrange_empty():
 
 def test_arrange_dock_top():
     container = Widget(id="container")
+    container._parent = App()
     child = Widget(id="child")
     header = Widget(id="header")
     header.styles.dock = "top"
@@ -34,6 +36,7 @@ def test_arrange_dock_top():
 
 def test_arrange_dock_left():
     container = Widget(id="container")
+    container._parent = App()
     child = Widget(id="child")
     header = Widget(id="header")
     header.styles.dock = "left"
@@ -51,6 +54,7 @@ def test_arrange_dock_left():
 
 def test_arrange_dock_right():
     container = Widget(id="container")
+    container._parent = App()
     child = Widget(id="child")
     header = Widget(id="header")
     header.styles.dock = "right"
@@ -68,6 +72,7 @@ def test_arrange_dock_right():
 
 def test_arrange_dock_bottom():
     container = Widget(id="container")
+    container._parent = App()
     child = Widget(id="child")
     header = Widget(id="header")
     header.styles.dock = "bottom"