themeData property
The scrollbar theme data that defines the appearance of the scrollbar.
This provides access to all Flutter's built-in scrollbar customization options:
thickness: The width of the scrollbar track and thumbthumbColor: The color of the scrollbar thumb (the draggable part)trackColor: The color of the scrollbar track (background)radius: The radius of the scrollbar thumb cornersthumbVisibility: Whether the thumb should always be visibletrackVisibility: Whether the track should always be visibleinteractive: Whether the scrollbar can be draggedmainAxisMargin: Margin along the main axiscrossAxisMargin: Margin along the cross axis
If null, default Flutter scrollbar styling will be applied.
Implementation
final ScrollbarThemeData? themeData;