ChartViewDelegate not called when barChart is out of screen

[ludovicjamet]

I got a horizontal scrollView with a BarChartView like :

• ScrollView
  • ContentView
    • View (with Labels and a button to scrollTo) frame: (0,0, ScreenWidth, ScreenHeight)
    • BarChartView frame: (ScreenWidth, 0, ScreenWidth, ScreenHeight)

On viewDidLoad() I'm calling a setChart methods

func drawActivityChart() {

    activityChart.chartDescription?.text = ""
    activityChart.noDataText = "Aucunes données à afficher"
    activityChart.doubleTapToZoomEnabled = false
    activityChart.drawValueAboveBarEnabled = false
    activityChart.drawBarShadowEnabled = false
    activityChart.dragYEnabled = false
    activityChart.dragXEnabled = false
    activityChart.legend.enabled = false
    activityChart.drawGridBackgroundEnabled = false

    activityChart.xAxis.drawLabelsEnabled = false
    activityChart.xAxis.drawAxisLineEnabled = false
    activityChart.xAxis.drawGridLinesEnabled = false

    activityChart.leftAxis.drawGridLinesEnabled = false
    activityChart.leftAxis.drawAxisLineEnabled = false
    activityChart.leftAxis.drawLabelsEnabled = false

    activityChart.rightAxis.drawGridLinesEnabled = false
    activityChart.rightAxis.drawAxisLineEnabled = false
    activityChart.rightAxis.drawLabelsEnabled = false

    //activityChart.animate(yAxisDuration: 0.5)

    // Draw graph
    let months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
    let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0, 4.0, 18.0, 2.0, 4.0, 5.0, 4.0]

    var dataEntries: [BarChartDataEntry] = []

    for i in 0..<months.count {
      let dataEntry = BarChartDataEntry(x: Double(i), y: unitsSold[i])
      dataEntries.append(dataEntry)
    }

    let chartDataSet = BarChartDataSet(values: dataEntries, label: nil)
    chartDataSet.drawValuesEnabled = false
    chartDataSet.colors = [UIColor].init(repeating: Default.white.withAlphaComponent(0.2), count: 12)
    chartDataSet.highlightColor = Default.white
    chartDataSet.highlightEnabled = true

    let chartData = BarChartData(dataSets: [chartDataSet])
    chartData.highlightEnabled = true
    activityChart.data = chartData

}

Tap on graph to hilight a bar is not working at all (like all gesture). It the barChart is visible on screen everything works properly of course.

[liuxuan30]

need some context first. why the bar chart view is out of screen, yet you still can see and tap it?

[ludovicjamet]

Because graph is on an horizontal scrollview, in page mode. I need to set a custom gesture when the scrollview scrolled to the graph. I'm not sure it's a Charts bug, it's probably a workaround with UIGesture.

[liuxuan30]

You don't clear the paradox here. You don't see the bar on the screen yet you can tap it.

Tap on graph to hilight a bar is not working at all (like all gesture). It the barChart is visible on screen everything works properly of course.

This sounds works expected to me. But you should be able to add some breakpoints and debug I believe.