AnimationHelper.cs

using System;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;

namespace VocabCoach;

/// <summary>Zentrale Animationen, die in mehreren Views wiederverwendet werden.</summary>
public static class AnimationHelper
{
    /// <summary>Shrink + Fade-In (für Lösch-Animation im Dashboard, 250ms).</summary>
    public static async Task AnimateDeleteAsync(FrameworkElement? element)
    {
        if (element == null)
        {
            await Task.Delay(150);
            return;
        }

        var tgg = element.RenderTransform as TransformGroup;
        if (tgg == null)
        {
            tgg = new TransformGroup();
            element.RenderTransform = tgg;
        }

        var scale = tgg.Children.OfType<ScaleTransform>().FirstOrDefault();
        if (scale == null)
        {
            scale = new ScaleTransform(1, 1);
            tgg.Children.Add(scale);
        }

        element.RenderTransformOrigin = new Point(0.5, 0.5);

        var dur = new Duration(TimeSpan.FromMilliseconds(250));
        var ease = new CubicEase { EasingMode = EasingMode.EaseIn };

        scale.BeginAnimation(ScaleTransform.ScaleXProperty, new DoubleAnimation(0.8, dur) { EasingFunction = ease });
        scale.BeginAnimation(ScaleTransform.ScaleYProperty, new DoubleAnimation(0.8, dur) { EasingFunction = ease });
        element.BeginAnimation(UIElement.OpacityProperty, new DoubleAnimation(0, dur) { EasingFunction = ease });

        await Task.Delay(250);
    }

    /// <summary>Shrink + Fade-Out (für Vokabel-Entfernung im Import, 350ms).</summary>
    public static void AnimateRemove(FrameworkElement element)
    {
        var tgg = element.RenderTransform as TransformGroup ?? new TransformGroup();
        if (!tgg.Children.OfType<ScaleTransform>().Any())
            tgg.Children.Add(new ScaleTransform(1, 1));

        var scale = tgg.Children.OfType<ScaleTransform>().First();

        element.RenderTransformOrigin = new Point(0.5, 0.5);
        element.RenderTransform = tgg;

        var ease = new CubicEase { EasingMode = EasingMode.EaseOut };
        scale.BeginAnimation(ScaleTransform.ScaleXProperty, new DoubleAnimation(1, 0.6, TimeSpan.FromMilliseconds(350)) { EasingFunction = ease });
        scale.BeginAnimation(ScaleTransform.ScaleYProperty, new DoubleAnimation(1, 0.6, TimeSpan.FromMilliseconds(350)) { EasingFunction = ease });
        element.BeginAnimation(UIElement.OpacityProperty, new DoubleAnimation(1, 0, TimeSpan.FromMilliseconds(350)) { EasingFunction = ease });
    }
}