Legend hittest always return null

[mikezw]

Hi, I want to use hittest of legend, but it always return null. And because of SeriesPosMap is private, If I implementation mylegend base Legend , I must copy all logic of SeriesPosMap. So I make some changes like belows.

Changes

  protected override HitTestResult LegendHitTest(HitTestArguments args)
        {
            HitTestResult hitTestResult = null;
            if (this.IsLegendVisible && this.PlotModel.IsLegendVisible)
            {
                ScreenPoint point = args.Point;
                if (this.IsPointInLegend(point))
                {
                    Element seriesElement = null;
                    if (this.SeriesPosMap != null && this.SeriesPosMap.Count > 0)
                    {
                        foreach (KeyValuePair<Series.Series, OxyRect> kvp in this.SeriesPosMap)
                        {
                            if (kvp.Value.Contains(point))
                            {
                                if (this.ShowInvisibleSeries)
                                {
                                    kvp.Key.IsVisible = !kvp.Key.IsVisible;
                                    this.PlotModel.InvalidatePlot(false);
                                    seriesElement = kvp.Key;
                                    break;
                                }
                            }
                        }
                    }
                    //Return Series if ShowInvisibleSeries is true .
                    hitTestResult = new HitTestResult(this, point, seriesElement);
                }
            }
            return hitTestResult;
        }

Can these be added to the release?

[VisualMelon]

Linking #1814

[VisualMelon]

Exposing this sort of thing is definitely something I'd like to look into. There is additional discussion in #1657

[mikezw]

So how about the progress? Change SeriesPosMap to protect will give more expandable to legend.

Is there anything I can do to help?

[VisualMelon]

I wouldn't want to expose SeriesPostMap in its current state. We need a more comprehensive design that includes e.g. showing non-series items on the legend/multiple entries per series. If there is demand (and there seems to be) I'd sooner add something like your HitTest method which uses the existing abstractions, but will need a proper review to see if it makes sense.