SlidingImage.xaml.cs

using System;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Animation;

namespace KenBurns
{
    public sealed partial class SlidingImage2 : UserControl
    {
        public static DependencyProperty SourceProperty = DependencyProperty.Register(
            "Source",
            typeof(ImageSource),
            typeof(SlidingImage),
            new PropertyMetadata(null, (o, e) => ((FrameworkElement)o).InvalidateMeasure()));

        public SlidingImage2()
        {
            this.InitializeComponent();

            this.SizeChanged += this.OnSizeChanged;
        }

        public ImageSource Source
        {
            get
            {
                return this.GetValue(SourceProperty) as ImageSource;
            }

            set
            {
                this.SetValue(SourceProperty, value);
            }
        }

        protected override Size MeasureOverride(Size availableSize)
        {
            var height = this.Source == null ? 0 : Math.Min(this.Image.ActualHeight, availableSize.Height);

            return new Size(availableSize.Width, height);
        }

        private void OnSizeChanged(object sender, SizeChangedEventArgs e)
        {
            this.Root.Clip = new RectangleGeometry { Rect = new Rect(new Point(0, 0), e.NewSize) };
            this.SetStoryboard();
        }

        private void OnImageOpened(object sender, RoutedEventArgs e)
        {
            this.InvalidateMeasure();
            this.SetStoryboard();
        }

        private void SetStoryboard()
        {
            var storyboard = (Storyboard) this.Resources["SlidingStoryboard"];

            if (storyboard.GetCurrentState() != ClockState.Stopped)
            {
                storyboard.Stop();
                storyboard.Seek(TimeSpan.Zero);
            }

            if (this.Image.ActualHeight > this.ActualHeight)
            {
                var finalHeight = (this.Image.ActualHeight - this.ActualHeight)*-1;

                var animation = (DoubleAnimationUsingKeyFrames) storyboard.Children[0];

                animation.KeyFrames.Clear();

                var currentTime = TimeSpan.FromSeconds(3);

                animation.KeyFrames.Add(new LinearDoubleKeyFrame
                {
                    KeyTime = KeyTime.FromTimeSpan(currentTime),
                    Value = 0
                });

                currentTime = currentTime.Add(TimeSpan.FromSeconds(finalHeight/-10));

                animation.KeyFrames.Add(new EasingDoubleKeyFrame
                {
                    KeyTime = KeyTime.FromTimeSpan(currentTime),
                    Value = finalHeight,
                    EasingFunction = new QuadraticEase {EasingMode = EasingMode.EaseInOut}
                });

                currentTime = currentTime.Add(TimeSpan.FromSeconds(2));

                animation.KeyFrames.Add(new LinearDoubleKeyFrame
                {
                    KeyTime = KeyTime.FromTimeSpan(currentTime),
                    Value = finalHeight
                });

                currentTime = currentTime.Add(TimeSpan.FromMilliseconds(500));

                animation.KeyFrames.Add(new EasingDoubleKeyFrame
                {
                    KeyTime = KeyTime.FromTimeSpan(currentTime),
                    Value = 0,
                    EasingFunction = new CubicEase {EasingMode = EasingMode.EaseInOut}
                });

                storyboard.Begin();
            }
        }
    }
}