/// <summary>
        /// Adds selected item (photo) to the SelectedPhotos collection
        /// </summary>
        private void allPhotosListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // TODO When switching folders automatically select photos that are in the SelectedPhotos collection
            // TODO DO NOT remove the first selected photo when changing folders

            if (allPhotosListBox.SelectedItems.Count > Constants.MaxSelectedPhotos)
            {
                // Maximum number of selected photos reached
                allPhotosListBox.SelectedItems.RemoveAt(allPhotosListBox.SelectedItems.Count - 1);
                return;
            }

            System.Collections.IList     eAdded        = e.AddedItems;
            System.Collections.IList     eRemoved      = e.RemovedItems;
            ObservableCollection <Photo> selectedItems = AttachedProperties.GetSelectedPhotos(allPhotosListBox);

            if (eAdded.Count != 0)
            {
                // New photo selected
                selectedItems.Add((Photo)eAdded[0]);
            }
            else if (eRemoved.Count != 0)
            {
                // Photo unselected
                selectedItems.Remove((Photo)eRemoved[0]); // When folders change and SelectionChanged is raised this removes the first photo from the SelectedPhotos
            }
        }