This pull request improves how bar chart value labels are rendered by utilizing the IRenderLast interface. This ensures that labels are drawn at the top level. The change affects Bar, BarPlot, and introduces a Clone() method for LabelStyle.

• Fixes overlapping label issue where value labels could be hidden by one before it.

Changes Made

Bar.cs

• Implemented IRenderLast in the Bar class.
  

• Split rendering logic: Render() draws the bar body, while RenderLast() renders the label on top.
  

• Stored PixelRect and LabelStyle (cloned) for deferred rendering.
  

public void Render(RenderPack rp, IAxes axes, SKPaint paint, LabelStyle labelStyle)
{
    // Render bar body and store label data for later
}

public void RenderLast(RenderPack rp)
{
    // Render label safely using a new SKPaint instance
}

BarPlot.cs

• Now implements IRenderLast.
  

• Calls RenderLast() on each individual Bar it contains.
  

• Updated RenderLast() method to be virtual (same as Render()), allowing future extensibility.
  

    public virtual void RenderLast(RenderPack rp)
    {
        foreach (Bar bar in Bars)
        {
            bar.RenderLast(rp);
        }
    }

LabelStyle.cs

• Added Clone() method to safely copy all styling properties to avoid shared state or mutation between render passes.
  

public LabelStyle Clone()
{
    return new LabelStyle
    {
        // All public properties are copied here
    };
}

Note: I included a Clone() method in LabelStyle to defensively copy the style during Render(...). It may not be strictly necessary, but it's added to ensure stable label appearance in RenderLast().

Before / After

Before: Value labels could appear behind the one above it if there is no space.

After: Labels are now rendered on top of all.

Note: With this update, bar value labels are rendered after all other plot elements, including axis lines and grid ticks.

• Fix Bar: add option to have text labels render last #4855