ScatterSeries points change color when hovering over

[bennewehn]

I'm working on a chart with point selection. With ScatterSeries and ChartPointPointerDown some
points change the color when hovering over.

Reproduce

 public partial class MainWindow : Window
 {
     public MainWindow()
     {
         InitializeComponent();
         Series[0] = S;
         S.ChartPointPointerDown += S_ChartPointPointerDown;
         DataContext = this;
     }

     private LiveChartsCore.Kernel.ChartPoint<ObservablePoint, 
         LiveChartsCore.SkiaSharpView.Drawing.Geometries.CircleGeometry, 
         LiveChartsCore.SkiaSharpView.Drawing.Geometries.LabelGeometry>? lastPoint = null;
   
     private void S_ChartPointPointerDown(LiveChartsCore.Kernel.Sketches.IChartView chart, LiveChartsCore.Kernel.ChartPoint<ObservablePoint, LiveChartsCore.SkiaSharpView.Drawing.Geometries.CircleGeometry, LiveChartsCore.SkiaSharpView.Drawing.Geometries.LabelGeometry>? point)
     {
         if(lastPoint?.Visual != null)
         {
             lastPoint.Visual.Fill = new SolidColorPaint(SKColors.Blue);
         }

         if(point?.Visual != null)
         {
             point.Visual.Fill = new SolidColorPaint(SKColors.Red);
         }

         lastPoint = point;
     }

     public ISeries[] Series { get; set; } = new ISeries[1];

     ScatterSeries<ObservablePoint> S { get; set; } = new ScatterSeries<ObservablePoint>
     {
         Values = new ObservableCollection<ObservablePoint>
         {
             new(2.2, 5.4),
             new(4.5, 2.5),
             new(4.2, 7.4),
             new(6.4, 9.9),
             new(4.2, 9.2),
             new(5.8, 3.5),
             new(7.3, 5.8),
             new(8.9, 3.9),
             new(6.1, 4.6),
             new(9.4, 7.7),
             new(8.4, 8.5),
             new(3.6, 9.6),
             new(4.4, 6.3),
             new(5.8, 4.8),
             new(6.9, 3.4),
             new(7.6, 1.8),
             new(8.3, 8.3),
             new(9.9, 5.2),
             new(8.1, 4.7),
             new(7.4, 3.9),
             new(6.8, 2.3),
             new(5.3, 7.1),
         }

     };
 }

Screenshots

2023-08-22.13-39-33.mp4

[beto-rodriguez]

Visuals do not implement INotifyPropertyChanged, that is by design, it means that the UI will not update automatically,

Have you tried to call a chart update? like shown here https://livecharts.dev/docs/Maui/2.0.0-beta.920/samples.events.cartesian

chart.Invalidate();

[bennewehn]

Same problem when using chart.Invalidate();

 private void S_ChartPointPointerDown(LiveChartsCore.Kernel.Sketches.IChartView chart, 
     LiveChartsCore.Kernel.ChartPoint<ObservablePoint, 
     LiveChartsCore.SkiaSharpView.Drawing.Geometries.CircleGeometry, 
     LiveChartsCore.SkiaSharpView.Drawing.Geometries.LabelGeometry>? point)
 {
     if (point?.Visual == null) return;

     if(lastPoint?.Visual != null)
     {
         lastPoint.Visual.Fill = null; 
     }

     point.Visual.Fill = new SolidColorPaint(SKColors.Red);
     chart.Invalidate();
     lastPoint = point;
 }