Animation Setters must contain correct type

[stevemonaco]

Seems obvious, but maybe not entirely. I'm writing C#-backed animations and was having issues with freezes. Controls with animations that never started, animation Tasks which would never return from its await, etc. No exception, no debug output. I was writing a scaling animation which has a setter like this:

Setters = { new Setter(ScaleTransform.ScaleXProperty, 1), new Setter(ScaleTransform.ScaleYProperty, 1) }

It turns out there's an InvalidCastException which I don't get in my app. I eventually put the code into the Avalonia sandbox to figure out the issue. The correct setters with explicit double usage are below:

Setters = { new Setter(ScaleTransform.ScaleXProperty, 1d), new Setter(ScaleTransform.ScaleYProperty, 1d) }

The cast exception occurs here:

Avalonia/src/Avalonia.Base/Animation/AnimationInstance`1.cs

Lines 133 to 143 in 9e24f9b

	private void DoPlayStates()
	{
	if (_clock!.PlayState == PlayState.Stop || _baseClock.PlayState == PlayState.Stop)
	DoComplete();
	if (!_gotFirstKFValue)
	{
	_firstKFValue = (T)_animator.First().Value!;
	_gotFirstKFValue = true;
	}
	}

And is swallowed and forwarded into an observable error here:

Avalonia/src/Avalonia.Base/Animation/AnimationInstance`1.cs

Lines 100 to 110 in 9e24f9b

	public void Step(TimeSpan frameTick)
	{
	try
	{
	InternalStep(frameTick);
	}
	catch (Exception e)
	{
	PublishError(e);
	}
	}

There should probably be some better way to mitigate this scenario.