hitTestDots method

@override int hitTestDots(double dx, int count, double current)

Returns the index of the section that contains dx.

Sections or hit-targets are calculated differently in some effects

Implementation

@override
int hitTestDots(double dx, int count, double current) {
  final switchPoint = (maxVisibleDots / 2).floor();
  if (fixedCenter) {
    return super.hitTestDots(dx, count, current) -
        switchPoint +
        current.floor();
  } else {
    final firstVisibleDot =
        (current < switchPoint || count - 1 < maxVisibleDots)
            ? 0
            : min(current - switchPoint, count - maxVisibleDots).floor();
    final lastVisibleDot =
        min(firstVisibleDot + maxVisibleDots, count - 1).floor();
    var offset = 0.0;
    for (var index = firstVisibleDot; index <= lastVisibleDot; index++) {
      if (dx <= (offset += dotWidth + spacing)) {
        return index;
      }
    }
  }
  return -1;
}