Custom Tooltip in .700 for CartesianChart in WPF not working

[andrew-baylis]

Describe the bug
In WPF, the Cartesian Chart does not allow the setting of custom tooltips in the constructor or XML

To Reproduce
Use the code and approach suggested in your online documentation for beta 700

Expected behavior
The new tooltip class being used. Instead, the default tooltip is always used.

Desktop (please complete the following information):

• OS: Windows 11

Additional context
I traced this behaviour to the InitializeCore method in CartesianChart.cs within LiveChartsCore.SkiaSharpView.WPF
This method is called in the OnApplyTempate of the chart (i.e. after the constructor) and it sets the tooltip to a new SKDefaultTooltip.
tooltip = new SKDefaultTooltip(); // Template.FindName("tooltip", this) as IChartTooltip<SkiaSharpDrawingContext>;

I see that the legend is also created here, meaning that this cannot be overridden in the constructor either.

Moving the lines:

        legend = new SKDefaultLegend(); // Template.FindName("legend", this) as IChartLegend<SkiaSharpDrawingContext>;
        tooltip = new SKDefaultTooltip(); // Template.FindName("tooltip", this) as IChartTooltip<SkiaSharpDrawingContext>;

to the constructor allows the Tooltip to be replaced in XML or the constructor as expected.

[andrew-baylis]

Alternatively, we can leave the lines in the InitializeCore method, but check to see if they have already been assigned before overwriting them:

legend ??= new SKDefaultLegend(); // Template.FindName("legend", this) as IChartLegend<SkiaSharpDrawingContext>;
tooltip ??= new SKDefaultTooltip(); // Template.FindName("tooltip", this) as IChartTooltip<SkiaSharpDrawingContext>;

[beto-rodriguez]

This is already working in the latest release thanks for the report.