Panel border is invisible sometimes.

[abhaynath]

I am using the latest version of Dock.

Sometimes the border is getting invisible if the panel is dragged.

Adding screenshots and the axaml file for reference.

My monitor resolution is 1366x768 if is resolution specific issue.

XAML :
xaml.txt

[wieslawsoltes]

It's probably issue with screen resolution and DPI, probably related to math in splitter control calculations.

[OlivierMiracle]

I have read through the ProportionalStackPanel.cs. I was assuming that multiplying by proportion variable causes the issue which turned out to be the case.

In ArrangeOverride and MeasureOverride methods when calculating Width/Height of the children the following formula is used:

  // case Orientation.Horizontal
  var width = Math.Max(0, (arrangeSize.Width - splitterThickness) * proportion);

  // case Orientation.Vertical
  var height = Math.Max(0, (arrangeSize.Height - splitterThickness) * proportion);

I have allowed myself to write some helper function to calculate the proper width/height of the control:

private double CalculateDimension(double dimension, double proportion, int childIndex)
{
    var childDimension = dimension * proportion;
    var flooredChildDimension = Math.Floor(childDimension);
    
    // checks whether division doesn't leave a fraction
    if (childDimension == flooredChildDimension)
        return Math.Max(0, flooredChildDimension);
    else
    {
        // if so, it assigns the divided pixel to the first control in proportional split
        var isFirst = childIndex == 0 ? 1 : 0;
        return Math.Max(0, flooredChildDimension + isFirst);
    }
}

Then it's used like this:

var height = CalculateDimension(arrangeSize.Height - splitterThickness, proportion, i);