Avalonia/Perspex/Layout/LayoutHelper.cs

// -----------------------------------------------------------------------
// <copyright file="LayoutHelper.cs" company="Steven Kirk">
// Copyright 2014 MIT Licence. See licence.md for more information.
// </copyright>
// -----------------------------------------------------------------------

namespace Perspex.Layout
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using Perspex.Controls;

    public static class LayoutHelper
    {
        public static Size MeasureDecorator(
            Control decorator,
            Control content,
            Size availableSize, 
            Thickness padding)
        {
            double width = 0;
            double height = 0;

            if (decorator.Visibility != Visibility.Collapsed)
            {
                if (content != null)
                {
                    content.Measure(availableSize);
                    Size s = content.DesiredSize.Value.Inflate(padding);
                    width = s.Width;
                    height = s.Height;
                }

                if (decorator.Width > 0)
                {
                    width = decorator.Width;
                }

                if (decorator.Height > 0)
                {
                    height = decorator.Height;
                }
            }

            return new Size(width, height);
        }
    }
}