handleThumbPressStartVertical method
Handler called when a long press gesture has started on the vertical scrollbar.
Begins the fade out animation and initializes dragging the scrollbar thumb.
Implementation
@protected
@mustCallSuper
void handleThumbPressStartVertical(Offset position) {
Offset localPosition = position.toLocal(context);
_fadeoutTimerV?.cancel();
fadeoutAnimationControllerVertical.forward();
_startDragScrollbarAxisOffsetV = localPosition;
_lastDragUpdateOffsetV = localPosition;
_startDragThumbOffsetV = verticalScrollbar.getThumbScrollOffset();
_thumbDraggingV = true;
}