handleThumbPressStartHorizontal method
Handler called when a long press gesture has started on the horizontal scrollbar.
Begins the fade out animation and initializes dragging the scrollbar thumb.
Implementation
@protected
@mustCallSuper
void handleThumbPressStartHorizontal(Offset position) {
Offset localPosition = position.toLocal(context);
_fadeoutTimerH?.cancel();
fadeoutAnimationControllerHorizontal.forward();
_startDragScrollbarAxisOffsetH = localPosition;
_lastDragUpdateOffsetH = localPosition;
_startDragThumbOffsetH = horizontalScrollbar.getThumbScrollOffset();
_thumbDraggingH = true;
}