public static Task <bool> BezierPathTo(this VisualElement view,
Point pt1, Point pt2, Point pt3,
uint length = 250,
BezierTangent bezierTangent = BezierTangent.None,
Easing easing = null)
{
easing = easing ?? Easing.Linear;
TaskCompletionSource <bool> taskCompletionSource = new TaskCompletionSource <bool>();
WeakReference <VisualElement> weakViewRef = new WeakReference <VisualElement>(view);
Rectangle bounds = view.Bounds;
BezierSpline bezierSpline = new BezierSpline(bounds.Center, pt1, pt2, pt3);
Action <double> callback = t =>
{
VisualElement viewRef;
if (weakViewRef.TryGetTarget(out viewRef))
{
Point tangent;
Point point = bezierSpline.GetPointAtFractionLength(t, out tangent);
double x = point.X - bounds.Width / 2;
double y = point.Y - bounds.Height / 2;
viewRef.Layout(new Rectangle(new Point(x, y), bounds.Size));
if (bezierTangent != BezierTangent.None)
{
viewRef.Rotation = 180 * Math.Atan2(tangent.Y, tangent.X) / Math.PI;
if (bezierTangent == BezierTangent.Reversed)
{
viewRef.Rotation += 180;
}
}
}
};
Animation animation = new Animation(callback, 0, 1, easing);
animation.Commit(view, "BezierPathTo", 16, length,
finished: (value, cancelled) => taskCompletionSource.SetResult(cancelled));
return(taskCompletionSource.Task);
}
public static Task<bool> BezierPathTo(this VisualElement view,
Point pt1, Point pt2, Point pt3,
uint length = 250,
BezierTangent bezierTangent = BezierTangent.None,
Easing easing = null)
{
easing = easing ?? Easing.Linear;
TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
WeakReference<VisualElement> weakViewRef = new WeakReference<VisualElement>(view);
Rectangle bounds = view.Bounds;
BezierSpline bezierSpline = new BezierSpline(bounds.Center, pt1, pt2, pt3);
Action<double> callback = t =>
{
VisualElement viewRef;
if (weakViewRef.TryGetTarget(out viewRef))
{
Point tangent;
Point point = bezierSpline.GetPointAtFractionLength(t, out tangent);
double x = point.X - bounds.Width / 2;
double y = point.Y - bounds.Height / 2;
viewRef.Layout(new Rectangle(new Point(x, y), bounds.Size));
if (bezierTangent != BezierTangent.None)
{
viewRef.Rotation = 180 * Math.Atan2(tangent.Y, tangent.X) / Math.PI;
if (bezierTangent == BezierTangent.Reversed)
{
viewRef.Rotation += 180;
}
}
}
};
Animation animation = new Animation(callback, 0, 1, easing);
animation.Commit(view, "BezierPathTo", 16, length,
finished: (value, cancelled) => taskCompletionSource.SetResult(cancelled));
return taskCompletionSource.Task;
}