Vertical Line Configuration? about fl_chart HOT 3 CLOSED

LineTouchData getLineTouchData() {
    return LineTouchData(
      touchTooltipData: LineTouchTooltipData(
        tooltipBgColor: Colors.blueGrey.withOpacity(0.8),
        tooltipMargin: 100,
      ),
      touchCallback: (FlTouchEvent event, LineTouchResponse? response) {
        if (response == null || response.lineBarSpots == null) {
          return;
        }
        final index = response.lineBarSpots!.first.spotIndex;

        if (event is FlPanStartEvent) {
          ref.read(signalChartProvider.notifier).startDrag(index);
        } else if (event is FlPanUpdateEvent) {
          ref.read(signalChartProvider.notifier).updateDrag(index);
          ref.read(signalChartProvider.notifier).toggleSpotSelectionDuringDrag(index);
        } else if (event is FlPanEndEvent) {
          ref.read(signalChartProvider.notifier).endDrag();
        } else if (event is FlTapUpEvent) {
          ref.read(signalChartProvider.notifier).toggleSpotSelection(index);
        } else if (event is FlPointerHoverEvent) {
          ref.read(signalChartProvider.notifier).updateHover(index);
        } else if (event is FlPointerExitEvent) {
          ref.read(signalChartProvider.notifier).updateHover(-1);
        }
      },
      handleBuiltInTouches: false,
    );
  }

ExtraLinesData getExtraLinesData(SignalChartState state) {
    return ExtraLinesData(
      extraLinesOnTop: true,
      verticalLines: [
        if (state.dragStartIndex != null)
          VerticalLine(
            x: state.dragStartIndex!.toDouble(),
            color: Colors.black,
            strokeWidth: 2,
          ),
        if (state.hoverIndex != null)
          VerticalLine(
            x: state.hoverIndex!.toDouble(),
            color: Colors.black,
            strokeWidth: 2,
          ),
      ],
    );
  }

                      getTouchedSpotIndicator: (barData, spotIndexes) {
                        return spotIndexes.map((spotIndex) {
                          final FlSpot spot = barData.spots[spotIndex];
                          if (spot.x == 0 || spot.x == barData.spots.length - 1)
                            return null;
                          return TouchedSpotIndicatorData(
                            const FlLine(
                              color: Colors.white,
                              strokeWidth: 1,
                            ),
                            FlDotData(
                              show: true,
                              getDotPainter: (spot, percent, barData, index) {
                                return FlDotCirclePainter(
                                  radius: 4,
                                  color: Colors.transparent,
                                  strokeWidth: 1,
                                  strokeColor: Colors.transparent,
                                );
                              },
                            ),
                          );
                        }).toList();
                      },