onSecondaryTapDown property Null safety

GestureTapDownCallback? onSecondaryTapDown
final

A pointer that might cause a tap with a secondary button has contacted the screen at a particular location.

This is called after a short timeout, even if the winning gesture has not yet been selected. If the tap gesture wins, onSecondaryTapUp will be called, otherwise onSecondaryTapCancel will be called.

See also:

Implementation

final GestureTapDownCallback? onSecondaryTapDown;