[ADDITION] Allow for the Chart Colors list to be reset

* Added a ResetSeries property that when set to true, will cause the charts to redraw with a reset color list

Author: AaronBastian

src/LiveChartsCore/CartesianChart.cs

@@ -460,6 +460,10 @@ protected internal override void Measure()
         // get seriesBounds
         SetDrawMargin(ControlSize, new Margin());
 
+        if (_chartView.ResetSeries)
+        {
+            _nextSeries = 0;
+        }
         foreach (var series in VisibleSeries.Cast<ICartesianSeries<TDrawingContext>>())
         {
             if (series.SeriesId == -1) series.SeriesId = _nextSeries++;

src/LiveChartsCore/Kernel/Sketches/IChartView.cs

@@ -35,6 +35,11 @@ namespace LiveChartsCore.Kernel.Sketches;
 /// </summary>
 public interface IChartView
 {
+    /// <summary>
+    /// Gets or sets the ability to stop the chart colors from resetting.
+    /// </summary>
+    bool ResetSeries { get; set; }
+
     /// <summary>
     /// Gets the core.
     /// </summary>
@@ -65,7 +70,7 @@ public interface IChartView
     LvcSize ControlSize { get; }
 
     /// <summary>
-    /// Gets or sets the draw margin, if this property is null, the library will calculate a margin, this margin is the distance 
+    /// Gets or sets the draw margin, if this property is null, the library will calculate a margin, this margin is the distance
     /// between the view bounds and the drawable area.
     /// </summary>
     /// <value>
@@ -82,7 +87,7 @@ public interface IChartView
     TimeSpan AnimationsSpeed { get; set; }
 
     /// <summary>
-    /// Gets or sets the easing function, the library already provides many easing functions in the 
+    /// Gets or sets the easing function, the library already provides many easing functions in the
     /// LiveCharts.EasingFunction static class.
     /// </summary>
     /// <value>

src/LiveChartsCore/PieChart.cs

@@ -165,6 +165,12 @@ protected internal override void Measure()
         IndexBounds = new Bounds();
         PushoutBounds = new Bounds();
 
+        if (_chartView.ResetSeries)
+        {
+            _nextSeries = 0;
+            _drawnSeries.Clear();
+        }
+
         foreach (var series in VisibleSeries.Cast<IPieSeries<TDrawingContext>>())
         {
             if (series.SeriesId == -1) series.SeriesId = _nextSeries++;

src/skiasharp/LiveChartsCore.SkiaSharp/SKCharts/SKCartesianChart.cs

@@ -75,6 +75,9 @@ public SKCartesianChart(ICartesianChartView<SkiaSharpDrawingContext> view) : thi
         VisualElements = view.VisualElements;
     }
 
+    /// <inheritdoc cref="IChartView.ResetSeries">
+    public bool ResetSeries { get; set; }
+
     /// <inheritdoc cref="IChartView.DesignerMode" />
     public bool DesignerMode => false;
 

src/skiasharp/LiveChartsCore.SkiaSharp/SKCharts/SKPieChart.cs

@@ -73,6 +73,9 @@ public SKPieChart(IPieChartView<SkiaSharpDrawingContext> view) : this()
         VisualElements = view.VisualElements;
     }
 
+    /// <inheritdoc cref="IChartView.ResetSeries">
+    public bool ResetSeries { get; set; }
+
     /// <inheritdoc cref="IChartView.DesignerMode" />
     public bool DesignerMode => false;
 

src/skiasharp/LiveChartsCore.SkiaSharp/SKCharts/SKPolarChart.cs

@@ -75,6 +75,9 @@ public SKPolarChart(IPolarChartView<SkiaSharpDrawingContext> view) : this()
         VisualElements = view.VisualElements;
     }
 
+    /// <inheritdoc cref="IChartView.ResetSeries">
+    public bool ResetSeries { get; set; }
+
     /// <inheritdoc cref="IChartView.DesignerMode" />
     public bool DesignerMode => false;
 

src/skiasharp/LiveChartsCore.SkiaSharpView.Maui/CartesianChart.xaml.cs

@@ -116,7 +116,7 @@ public CartesianChart()
         chartBehaviour.On(this);
     }
 
-    #region bindable properties 
+    #region bindable properties
 
     /// <summary>
     /// The sync context property.
@@ -386,7 +386,10 @@ public CartesianChart()
         BindableProperty.Create(
             nameof(VisualElementsPointerDownCommand), typeof(ICommand), typeof(CartesianChart), null);
 
-    #endregion
+    public static readonly BindableProperty ResetSeriesProperty =
+        BindableProperty.Create(nameof(ResetSeries), typeof(bool), typeof(CartesianChart), false);
+
+#endregion
 
     #region events
 
@@ -415,6 +418,12 @@ public CartesianChart()
     /// <inheritdoc cref="IChartView.DesignerMode" />
     bool IChartView.DesignerMode => false;
 
+    public bool ResetSeries
+    {
+        get => (bool)GetValue(ResetSeriesProperty);
+        set => SetValue(ResetSeriesProperty, value);
+    }
+
     /// <inheritdoc cref="IChartView.CoreChart" />
     public IChart CoreChart => _core ?? throw new Exception("Core not set yet.");
 

src/skiasharp/LiveChartsCore.SkiaSharpView.Maui/PieChart.xaml.cs

@@ -321,6 +321,9 @@ public PieChart()
         BindableProperty.Create(
             nameof(VisualElementsPointerDownCommand), typeof(ICommand), typeof(PieChart), null);
 
+    public static readonly BindableProperty ResetSeriesProperty =
+        BindableProperty.Create(nameof(ResetSeries), typeof(bool), typeof(PieChart), false);
+
     #endregion
 
     #region events
@@ -613,6 +616,13 @@ public ICommand? VisualElementsPointerDownCommand
         set => SetValue(VisualElementsPointerDownCommandProperty, value);
     }
 
+    /// <inheritdoc cref="IChartView.ResetSeries">
+    public bool ResetSeries
+    {
+        get => (bool)GetValue(ResetSeriesProperty);
+        set => SetValue(ResetSeriesProperty, value);
+    }
+
     #endregion
 
     /// <inheritdoc cref="IChartView{TDrawingContext}.GetPointsAt(LvcPoint, TooltipFindingStrategy)"/>

src/skiasharp/LiveChartsCore.SkiaSharpView.Maui/PolarChart.xaml.cs

@@ -107,7 +107,7 @@ public PolarChart()
         chartBehaviour.On(this);
     }
 
-    #region bindable properties 
+    #region bindable properties
 
     /// <summary>
     /// The sync context property.
@@ -362,6 +362,9 @@ public PolarChart()
         BindableProperty.Create(
             nameof(VisualElementsPointerDownCommand), typeof(ICommand), typeof(PolarChart), null);
 
+    public static readonly BindableProperty ResetSeriesProperty =
+        BindableProperty.Create(nameof(ResetSeries), typeof(bool), typeof(PolarChart), false);
+
     #endregion
 
     #region events
@@ -391,6 +394,13 @@ public PolarChart()
     /// <inheritdoc cref="IChartView.DesignerMode" />
     bool IChartView.DesignerMode => false;
 
+    /// <inheritdoc cref="IChartView.ResetSeries">
+    public bool ResetSeries
+    {
+        get => (bool)GetValue(ResetSeriesProperty);
+        set => SetValue(ResetSeriesProperty, value);
+    }
+
     /// <inheritdoc cref="IChartView.CoreChart" />
     public IChart CoreChart => _core ?? throw new Exception("Core not set yet.");