handleMouseEvent method

void handleMouseEvent(MouseEvent event, int localX, int localY)

Handles track clicks or dragging of the thumb to update the scroll offset.

Implementation

void handleMouseEvent(MouseEvent event, int localX, int localY) {
  if (_lastArea == null) return;
  final trackHeight = direction == LayoutDirection.vertical
      ? _lastArea!.height
      : _lastArea!.width;

  final total = _totalExtent;
  final view = _viewportExtent;
  if (trackHeight <= 0 || total <= 0) return;

  final mousePos = direction == LayoutDirection.vertical ? localY : localX;

  final double clickRatio = (mousePos / trackHeight).clamp(0.0, 1.0);
  final int maxScrollOffset = total - view;

  final int newOffset = (clickRatio * total).round().clamp(
    0,
    maxScrollOffset > 0 ? maxScrollOffset : 0,
  );
  _updateScrollOffset(newOffset);
}