gistfile1.txt

using System;

using AppKit;
using CoreAnimation;
using CoreGraphics;
using Foundation;

namespace CustomizeAnimationTest2
{
	public partial class ViewController : NSViewController
	{
		public ViewController (IntPtr handle) : base (handle)
		{
		}

		public override void ViewDidLoad ()
		{
			base.ViewDidLoad ();
			MyView view = new MyView (new CGRect (0, 0, 250, 250));
			View.AddSubview (view);
		}
	}

	public class MyView : NSView
	{
		NSColor color;
		NSBezierPath path;

		public MyView (IntPtr p) : base (p)
		{
			
		}

		public MyView (CGRect rect) : base (rect)
		{
			color = NSColor.Blue;
			path = new NSBezierPath ();
			path.MoveTo (Bounds.Location);
			path.LineTo (new CGPoint (Bounds.GetMaxX (), Bounds.GetMaxY ()));
			DrawLineWidth = 1;
			WantsLayer = true;
			Layer.BackgroundColor = NSColor.Gray.CGColor;
		}

		NSNumber _drawnLineWidth;

		public NSNumber DrawLineWidth
		{
			[Export ("DrawLineWidth")]
			get
			{
				return _drawnLineWidth;
			}
			[Export ("setDrawLineWidth:")]
			set
			{
				WillChangeValue ("DrawLineWidth");
				_drawnLineWidth = value;
				NeedsDisplay = true;
				DidChangeValue ("DrawLineWidth");
			}
		}

		public override bool AcceptsFirstResponder () => true;

		public override void MouseDown (NSEvent theEvent)
		{
			base.MouseDown (theEvent);
			((MyView)this.Animator).DrawLineWidth = NSNumber.FromNInt (DrawLineWidth.NIntValue + 10);
		}

		public override void DrawRect (CGRect dirtyRect)
		{
			base.DrawRect (dirtyRect);
			path.LineWidth = DrawLineWidth.NFloatValue;
			color.SetStroke ();
			path.Stroke ();
		}

		static CABasicAnimation drawnLineWidthBasicAnimation;

		[Export ("defaultAnimationForKey:")]
		static new NSObject DefaultAnimationFor (NSString key)
		{
			if (key == "DrawnLineWidth")
			{
				if (drawnLineWidthBasicAnimation == null)
				{
					drawnLineWidthBasicAnimation = new CABasicAnimation ();
					//drawnLineWidthBasicAnimation.Duration = 2.0f;
				}
				return drawnLineWidthBasicAnimation;
			}
			else
				return NSView.DefaultAnimationFor (key);
		}
	}
}