Another Screensaver with WPF

using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Media;
using RZWScreenSaver.Properties;

namespace RZWScreenSaver.SlidePages{
    /// <summary>
    /// Interaction logic for SimpleSlide.xaml
    /// </summary>
    public partial class SimpleSlide{
        public SimpleSlide() {
            InitializeComponent();
            imagePathText.Visibility = Settings.Default.ShowTitle ? Visibility.Visible : Visibility.Collapsed;
        }
        public override bool ShowTitle{
            get { return imagePathText.Visibility == Visibility.Visible; }
            set{ imagePathText.Visibility = value ? Visibility.Visible : Visibility.Collapsed; }
        }
        protected override void OnPictureSetChanged(object sender, EventArgs arg){
            base.OnPictureSetChanged(sender, arg);
            slideShowImage.Source = null;
        }
        protected override void OnShowPicture(object sender, PictureChangedEventArgs arg){
            base.OnShowPicture(sender, arg);
            var image = arg.Picture;
            var orientation = GetImageOrientation(image);

            imagePathText.Content = FormatImageDescription(image, arg.Path, arg.FileDate, orientation);

            switch (DisplayMode){
            case DisplayMode.OriginalOrFit:
                slideShowImage.Stretch = canImageFitScreen(image, orientation)? Stretch.None : Stretch.Uniform;
                break;
            case DisplayMode.OriginalOrFillCrop:
                slideShowImage.Stretch = canImageFitScreen(image, orientation) ? Stretch.None : Stretch.UniformToFill;
                break;
                // default just ignore.
            }
            slideShowImage.Source = image;
            imageOrientation.Angle = -(orientation ?? 0);
            if (!IsLandscape(orientation)){
                var parentWindow = (FrameworkElement) Parent;
                slideShowImage.Width = parentWindow.Height;
                slideShowImage.Height = parentWindow.Width;
            } else{
                slideShowImage.Width = slideShowImage.Height = double.NaN;
            }
        }
        protected override void OnDisplayModeChanged() {
            base.OnDisplayModeChanged();
            switch (DisplayMode){
            case DisplayMode.Original:
                slideShowImage.Stretch = Stretch.None;
                break;
            case DisplayMode.Stretch:   
                slideShowImage.Stretch = Stretch.Fill;
                break;
            case DisplayMode.Fit:
                slideShowImage.Stretch = Stretch.Uniform;
                break;
            case DisplayMode.FillCrop:
                slideShowImage.Stretch = Stretch.UniformToFill;
                break;
            case DisplayMode.OriginalOrFit:
            case DisplayMode.OriginalOrFillCrop:
                // effect takes on changing image.
                break;
            default:
                Trace.WriteLine("Unhandled mode: " + DisplayMode);
                break;
            }
        }
        bool canImageFitScreen(ImageSource image, int? orientation){
            Size imageSize;
            GetImageSizeByOrientation(image, orientation, out imageSize);

            var parentWindow = Parent as FrameworkElement;
            return parentWindow != null && imageSize.Width <= parentWindow.Width && imageSize.Height <= parentWindow.Height;
        }
    }
}