onVerticalDragUpdate property
Called when the user scrolls up or down.
Implementation
GestureDragUpdateCallback? get onVerticalDragUpdate => _onVerticalDragUpdate;
Implementation
set onVerticalDragUpdate(GestureDragUpdateCallback? value) {
if (_onVerticalDragUpdate == value) {
return;
}
final bool hadHandler = _onVerticalDragUpdate != null;
_onVerticalDragUpdate = value;
if ((value != null) != hadHandler) {
markNeedsSemanticsUpdate();
}
}