title property
The title used by this item. If the display mode is top or compact, this is shown as a tooltip. If it's open, this is shown by the side of the icon.
The text style is fetched from the closest NavigationPaneThemeData
If it' s a Text, its Text.data is used to display the tooltip. This is also used by Semantics to allow screen readers to read the screen.
Usually a Text.
Implementation
final Widget? title;