/// <summary>
/// Manages tracking the progress of an animation, running a callback with the information.
/// Returns a lifetime that ends when the animation has expired.
/// </summary>
public static Lifetime AnimateWith(this Animation animation, TimeSpan duration, AnimationCallback callback, Lifetime constraint = default(Lifetime))
{
var remaining = duration;
var life = constraint.CreateDependentSource();
animation.StepActions.Add(
step => {
remaining -= step.TimeStep;
if (remaining >= TimeSpan.Zero) {
callback(step, 1 - remaining.TotalSeconds / duration.TotalSeconds, duration - remaining);
} else {
life.EndLifetime();
}
},
life.Lifetime);
return life.Lifetime;
}