add is_scrolling

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added several new built-in CSS variables https://github.com/Textualize/textual/pull/5087
 - Added support for in-band terminal resize protocol https://github.com/Textualize/textual/pull/5217
 - Added TEXTUAL_THEME environment var, which should be a comma separated list of desired themes
+- Added `Widget.is_scrolling`
 
 ### Changed
 

src/textual/demo/widgets.py

@@ -367,6 +367,8 @@ def loop_first_last(values: Iterable[T]) -> Iterable[tuple[bool, bool, T]]:
     def update_log(self) -> None:
         """Update the Log with new content."""
         log = self.query_one(Log)
+        if self.is_scrolling:
+            return
         if not self.app.screen.can_view_entire(log) and not log.is_in_maximized_view:
             return
         self.log_count += 1
@@ -377,6 +379,8 @@ def loop_first_last(values: Iterable[T]) -> Iterable[tuple[bool, bool, T]]:
     def update_rich_log(self) -> None:
         """Update the Rich Log with content."""
         rich_log = self.query_one(RichLog)
+        if self.is_scrolling:
+            return
         if (
             not self.app.screen.can_view_entire(rich_log)
             and not rich_log.is_in_maximized_view
@@ -457,6 +461,8 @@ For detailed graphs, see [textual-plotext](https://github.com/Textualize/textual
 
     def update_sparks(self) -> None:
         """Update the sparks data."""
+        if self.is_scrolling:
+            return
         if (
             not self.app.screen.can_view_partial(self)
             and not self.query_one(Sparkline).is_in_maximized_view
@@ -490,6 +496,8 @@ Switches {
         yield Markdown(self.SWITCHES_MD)
         with containers.ItemGrid(min_column_width=32):
             for theme in BUILTIN_THEMES:
+                if theme.endswith("-ansi"):
+                    continue
                 with containers.HorizontalGroup():
                     yield Switch(id=theme)
                     yield Label(theme, name=theme)

src/textual/widget.py

@@ -2208,6 +2208,19 @@ class Widget(DOMNode):
         """Can this widget be scrolled?"""
         return self.styles.layout is not None or bool(self._nodes)
 
+    @property
+    def is_scrolling(self) -> bool:
+        """Is this widget currently scrolling?"""
+        for node in self.ancestors:
+            if not isinstance(node, Widget):
+                break
+            if (
+                node.scroll_x != node.scroll_target_x
+                or node.scroll_y != node.scroll_target_y
+            ):
+                return True
+        return False
+
     @property
     def layer(self) -> str:
         """Get the name of this widgets layer.