Merge branch 'docs-intro' into optimize-styles-apply

src/textual/_xterm_parser.py

@@ -63,7 +63,7 @@ class XTermParser(Parser[events.Event]):
             event: events.Event
             if buttons & 64:
                 event = (
-                    events.MouseScrollDown if button == 1 else events.MouseScrollUp
+                    events.MouseScrollUp if button == 1 else events.MouseScrollDown
                 )(sender, x, y)
             else:
                 event = (

src/textual/widget.py

@@ -194,7 +194,9 @@ class Widget(DOMNode):
         Returns:
             bool: True if horizontal and vertical scrolling is enabled.
         """
-        return self.allow_horizontal_scroll and self.allow_vertical_scroll
+        return self.is_scrollable and (
+            self.allow_horizontal_scroll or self.allow_vertical_scroll
+        )
 
     def _arrange(self, size: Size) -> DockArrangeResult:
         """Arrange children.