public static Task StaggeredChildren(
VisualElement rootElement,
AnimationDefinition animation,
int initialDelay, int staggeredDelay, bool clear)
{
var list = new List <Task>();
var delay = initialDelay;
var elements = rootElement.LogicalChildren;
foreach (var element in elements.OfType <VisualElement>())
{
var child = animation.Clone();
child.PauseBefore = delay;
if (clear)
{
element.ClearTransforms(0);
}
list.Add(element.Animate(child));
delay += staggeredDelay;
}
return(Task.WhenAll(list));
}
public static Task <bool> Animate(this VisualElement visualElement, AnimationDefinition animationDefinition)
{
var tcs = new TaskCompletionSource <bool>();
var animation = animationDefinition.CreateAnimation(visualElement);
var animationId = visualElement.Id.ToString();
// Prevent any opacity challenges when element starts hidden
if (animationDefinition.OpacityFromZero)
{
visualElement.Opacity = 0;
visualElement.IsVisible = true;
}
if (animationDefinition.PauseBefore > 0 ||
animationDefinition.PauseAfter > 0 ||
animationDefinition.RepeatCount > 1 ||
animationDefinition.Delay > 0)
{
Task.Run(async() =>
{
int remaining = animationDefinition.RepeatCount;
if (animationDefinition.PauseBefore > 0)
{
await Task.Delay(animationDefinition.PauseBefore);
}
animation.Commit(
owner: visualElement,
name: animationId,
rate: 16,
length: animationDefinition.Duration,
easing: null,
finished: async(f, cancelled) =>
{
if (!cancelled && animationDefinition.PauseAfter > 0)
{
await Task.Delay(animationDefinition.PauseAfter);
}
if (cancelled || remaining <= 0)
{
tcs.SetResult(cancelled);
}
},
repeat: () =>
{
remaining--;
return(remaining > 0);
});
});
}
else
{
animation.Commit(
owner: visualElement,
name: animationId,
rate: 16,
length: animationDefinition.Duration,
easing: null,
finished: (f, a) => tcs.SetResult(a));
}
return(tcs.Task);
}
