Mesen2/UI/Utilities/DynamicCroppedBitmap.cs

using Avalonia;
using Avalonia.Media;
using Avalonia.Media.Imaging;
using System;

namespace Mesen.Utilities
{
	public class DynamicCroppedBitmap : CroppedBitmap, IDynamicBitmap
	{
		public new event EventHandler? Invalidated;

		static DynamicCroppedBitmap()
		{
			SourceProperty.Changed.AddClassHandler<DynamicCroppedBitmap>((x, e) => {
				if(e.OldValue is IDynamicBitmap oldSource) {
					oldSource.Invalidated -= x.OnSourceInvalidated;
				}

				if(x.Source is IDynamicBitmap newSource) {
					newSource.Invalidated += x.OnSourceInvalidated;
				}

				x.Invalidate();
			});
		}

		public DynamicCroppedBitmap(IImage source, PixelRect sourceRect) : base(source, sourceRect)
		{
		}

		public void Invalidate()
		{
			Invalidated?.Invoke(this, EventArgs.Empty);
		}

		private void OnSourceInvalidated(object? sender, EventArgs e)
		{
			Invalidate();
		}
	}
}