A panel which arranges as many children as possible into one row and stretches them to uniformly consume the whole width

AutoUniformWidthWrapPanel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace KodeFisk
{
	public class AutoUniformWidthWrapPanel : Panel
	{
		public AutoUniformWidthWrapPanel()
		{
			MinimumColumnsOnLastRow = 1;
		}


		public int MinimumColumnsOnLastRow
		{
			get { return (int)GetValue(MinimumColumnsOnLastRowProperty); }
			set { SetValue(MinimumColumnsOnLastRowProperty, value); }
		}

		// Using a DependencyProperty as the backing store for MinimumColumnsOnLastRow.  This enables animation, styling, binding, etc...
		public static readonly DependencyProperty MinimumColumnsOnLastRowProperty =
			DependencyProperty.Register("MinimumColumnsOnLastRow", typeof(int), typeof(AutoUniformWidthWrapPanel), new PropertyMetadata(null));


		protected override Size MeasureOverride(Size availableSize)
		{
			var finalSize = new Size { Width = availableSize.Width };

			var rowHeight = 0d;
			var posX = 0d;

			foreach (var child in Children)
			{
				child.Measure(availableSize);
				posX += child.DesiredSize.Width;

				if (posX > availableSize.Width)
				{
					posX = child.DesiredSize.Width;
					finalSize.Height += rowHeight;
					rowHeight = child.DesiredSize.Height;
				}
				else
				{
					rowHeight = Math.Max(child.DesiredSize.Height, rowHeight);
				}
			}

			finalSize.Height += rowHeight;
			return finalSize;
		}

		protected override Size ArrangeOverride(Size finalSize)
		{
			var posY = 0d;

			var currentRow = new List<UIElement>();
			var rowHeight = 0d;

			foreach (var child in Children)
			{
				if (currentRow.Sum(x => x.DesiredSize.Width) + child.DesiredSize.Width <= finalSize.Width)
				{
					currentRow.Add(child);
					rowHeight = Math.Max(child.DesiredSize.Height, rowHeight);
				}
				else
				{
					var rowChildCount = currentRow.Count;
					var columnWidth = finalSize.Width / rowChildCount;
					for (int i = 0; i < rowChildCount; i++)
					{
						currentRow[i].Arrange(new Rect(columnWidth * i, posY, columnWidth, currentRow[i].DesiredSize.Height));
					}

					posY += rowHeight;
					rowHeight = child.DesiredSize.Height;
					currentRow = new List<UIElement>();
					currentRow.Add(child);
				}
			}

			if (currentRow.Count > 0)
			{
				var rowChildCount = currentRow.Count;
				var columnWidth = finalSize.Width / Math.Max(rowChildCount, MinimumColumnsOnLastRow);
				for (int i = 0; i < rowChildCount; i++)
				{
					currentRow[i].Arrange(new Rect(columnWidth * i, posY, columnWidth, currentRow[i].DesiredSize.Height));
				}
			}

			return finalSize;
		}
	}
}