private static void DoOpacityTransition(
IOpacityParams transitionParams,
FrameworkElement target,
RoutedEventHandler onLoaded,
Visibility?visibility)
{
var reverse = Transitionz.IsVisibilityHidden(visibility);
target.Opacity = reverse ? transitionParams.To : transitionParams.From;
if (onLoaded != null && Transitionz.HasFlag(transitionParams.TransitionOn, TransitionOn.Once))
{
target.Loaded -= onLoaded;
}
var a = new DoubleAnimation
{
From = reverse ? transitionParams.To : transitionParams.From,
To = reverse ? transitionParams.From : transitionParams.To,
FillBehavior = transitionParams.FillBehavior,
BeginTime = TimeSpan.FromMilliseconds(transitionParams.BeginTime),
Duration = new Duration(TimeSpan.FromMilliseconds(transitionParams.Duration)),
EasingFunction = reverse ? (transitionParams.ReverseEase ?? transitionParams.Ease) : transitionParams.Ease,
AutoReverse = transitionParams.AutoReverse,
};
// Directly adding RepeatBehavior to constructor breaks existing animations, so only add it if properly defined
if (transitionParams.RepeatBehavior == RepeatBehavior.Forever ||
transitionParams.RepeatBehavior.HasDuration ||
(transitionParams.RepeatBehavior.HasDuration && transitionParams.RepeatBehavior.Count > 0))
{
a.RepeatBehavior = transitionParams.RepeatBehavior;
}
a.SetDesiredFrameRate(24);
var storyboard = new Storyboard();
storyboard.Children.Add(a);
Storyboard.SetTarget(a, target);
Storyboard.SetTargetProperty(a, new PropertyPath(UIElement.OpacityProperty));
a.Completed += (_, __) =>
{
if (visibility.HasValue)
{
target.Visibility = visibility.Value;
}
target.Opacity = reverse ? transitionParams.From : transitionParams.To;
storyboard.Stop();
};
storyboard.Begin();
}
public static void SetOpacity(UIElement element, IOpacityParams value)
{
element.SetValue(OpacityProperty, value);
}
