mouseCursor property Null safety
The cursor for a mouse pointer when it enters or is hovering over the widget.
If mouseCursor is a MaterialStateProperty<MouseCursor>, MaterialStateProperty.resolve is used for the following MaterialStates:
If this property is null, MaterialStateMouseCursor.textable will be used.
The mouseCursor is the only property of TextField that controls the appearance of the mouse pointer. All other properties related to "cursor" stand for the text cursor, which is usually a blinking vertical line at the editing position.
final MouseCursor? mouseCursor;