async void OnViewModelPropertyChanged(string property)
{
switch (property)
{
case nameof(this.ViewModel.NextTitle):
button.Title = this.ViewModel.NextTitle;
break;
case nameof(this.ViewModel.Current):
await view.AnimateAsync(this.ViewModel.Current);
break;
}
}
public static async Task AnimateAsync(this NSView view, IAnimation animation)
{
// Tell the view to create a backing layer.
view.WantsLayer = true;
view.LayerContentsRedrawPolicy = NSViewLayerContentsRedrawPolicy.OnSetNeedsDisplay;
if (animation is TransformAnimation transformAnimation)
{
view.Layer.AnchorPoint = new CGPoint(0.5f, 0.5f);
var source = new TaskCompletionSource <bool>();
var curve = transformAnimation.Curve.ToNative();
var from = transformAnimation.From;
var to = transformAnimation.To;
var w = (float)view.Bounds.Width;
var h = (float)view.Bounds.Height;
view.Layer.AddAnimation("opacity", curve, from.Opacity, to.Opacity, (anim) => anim.AnimationStopped += (sender, e) => source.SetResult(true))
.AddAnimation("transform.scale.x", curve, from.ScaleX, to.ScaleX)
.AddAnimation("transform.scale.y", curve, from.ScaleY, to.ScaleY)
.AddAnimation("transform.translation.x", curve, from.TranslateX * w, to.TranslateX * w)
.AddAnimation("transform.translation.y", curve, -1 * from.TranslateY * h, -1 * to.TranslateY * h)
.AddAnimation("transform.rotation.z", curve, from.Rotation, to.Rotation);
view.Layer.Opacity = transformAnimation.To.Opacity;
view.Layer.Transform = transformAnimation.To.ToNative(view.Bounds.Size);
await source.Task;
}
else if (animation is SequenceAnimation sequenceAnimation)
{
foreach (var childAnimation in sequenceAnimation)
{
await view.AnimateAsync(childAnimation);
}
}
}