fix slow UI

Author: willmcgugan

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+
+## [0.75.1] - 2024-08-02
+
+### Fixed
+
+- Fixed issue with Enter events causing unresponsive UI
+
 ## [0.75.0] - 2024-08-01
 
 ### Added
@@ -2250,6 +2257,7 @@ https://textual.textualize.io/blog/2022/11/08/version-040/#version-040
 - New handler system for messages that doesn't require inheritance
 - Improved traceback handling
 
+[0.75.1]: https://github.com/Textualize/textual/compare/v0.75.0...v0.75.1
 [0.75.0]: https://github.com/Textualize/textual/compare/v0.74.0...v0.75.0
 [0.74.0]: https://github.com/Textualize/textual/compare/v0.73.0...v0.74.0
 [0.73.0]: https://github.com/Textualize/textual/compare/v0.72.0...v0.73.0

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "textual"
-version = "0.75.0"
+version = "0.75.1"
 homepage = "https://github.com/Textualize/textual"
 repository = "https://github.com/Textualize/textual"
 documentation = "https://textual.textualize.io/"

src/textual/scrollbar.py

@@ -304,10 +304,12 @@ def _on_hide(self, event: events.Hide) -> None:
             self.grabbed = None
 
     def _on_enter(self, event: events.Enter) -> None:
-        self.mouse_over = True
+        if event.node is self:
+            self.mouse_over = True
 
     def _on_leave(self, event: events.Leave) -> None:
-        self.mouse_over = False
+        if event.node is self:
+            self.mouse_over = False
 
     def action_scroll_down(self) -> None:
         """Scroll vertical scrollbars down, horizontal scrollbars right."""

src/textual/widget.py

@@ -3848,11 +3848,13 @@ def _on_mount(self, event: events.Mount) -> None:
             self.show_horizontal_scrollbar = True
 
     def _on_leave(self, event: events.Leave) -> None:
-        self.mouse_hover = False
-        self.hover_style = Style()
+        if event.node is self:
+            self.mouse_hover = False
+            self.hover_style = Style()
 
     def _on_enter(self, event: events.Enter) -> None:
-        self.mouse_hover = True
+        if event.node is self:
+            self.mouse_hover = True
 
     def _on_focus(self, event: events.Focus) -> None:
         self.has_focus = True