swift SCICustomAnnotation not displayed on correct location

Hi, there.

Hi, there.

Thanks for writing to us.

If I understand your issue correctly, you can subclass SCISeriesSelectionModifier, get selected series, and update your annotation coordinate in some callback, like this

import SciChart.Protected.SCISeriesSelectionModifier
class CustomSelectionModifier: SCISeriesSelectionModifier {
    var onSelectionChange: ((Double) -> Void)?

    override func performSelection(_ renderableSeries: ISCIRenderableSeries) {
        super.performSelection(renderableSeries)

        guard let xPosition = (renderableSeries.dataSeries as? SCIXyDataSeries)?.xValues.toArray().first
        else { return }

        onSelectionChange?(xPosition as! Double)

        deselectAllBut(renderableSeries)
    }
}

class ColumnChartView: SCDSingleChartViewController<SCIChartSurface> {

    override var associatedType: AnyClass { return SCIChartSurface.self }

    override func initExample() {
        let xAxis = SCINumericAxis()
        xAxis.growBy = SCIDoubleRange(min: 0.1, max: 0.1)
        let yAxis = SCINumericAxis()
        yAxis.growBy = SCIDoubleRange(min: 0, max: 0.1)

        let seriesCollection = SCIRenderableSeriesCollection()

        let yValues = [1, 50, 100];
        for i in 0 ..< yValues.count {
            let dataSeries = SCIXyDataSeries(xType: .double, yType: .double)
            dataSeries.append(x: i, y: yValues[i])

            let rSeries = createSeries(dataSeries: dataSeries)
            seriesCollection.add(rSeries)
        }

        let customAnnotationGreen = SCICustomAnnotation()
        customAnnotationGreen.customView = SCIImageView.init(image: #imageLiteral(resourceName: "image.arrow.green"))
        customAnnotationGreen.set(x1: 0)
        customAnnotationGreen.set(y1: 105)

        let seriesSelectionModifier = CustomSelectionModifier()
        seriesSelectionModifier.onSelectionChange = { xPosition in
            customAnnotationGreen.set(x1: xPosition)
        }

        self.surface.annotations = SCIAnnotationCollection(collection: [customAnnotationGreen])

        SCIUpdateSuspender.usingWith(surface) {
            self.surface.xAxes.add(xAxis)
            self.surface.yAxes.add(yAxis)
            self.surface.renderableSeries = seriesCollection//.add(rSeries)
            self.surface.chartModifiers.add(SCDExampleBaseViewController.createDefaultModifiers())
            self.surface.chartModifiers.add(seriesSelectionModifier)
        }
    }

    private func createSeries(dataSeries: SCIXyDataSeries) -> ISCIRenderableSeries {
        let rSeries = SCIFastColumnRenderableSeries()
        rSeries.dataSeries = dataSeries
        rSeries.dataPointWidth = 0.3

        return rSeries
    }
}