Another Screensaver with WPF

using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Forms;
using System.Windows.Input;
using RZWScreenSaver.Properties;
using KeyEventArgs=System.Windows.Input.KeyEventArgs;
using ListView=System.Windows.Controls.ListView;
using MessageBox=System.Windows.MessageBox;
using RadioButton=System.Windows.Controls.RadioButton;

namespace RZWScreenSaver {
    /// <summary>
    /// Interaction logic for ConfigDialog.xaml
    /// </summary>
    partial class ConfigDialog{
        const int NumberOfPictureSet = 4;
        #region ctors
        public ConfigDialog() {
            InitializeComponent();
            defaultRadioButtons = new[]
                                  {imageFolderDefault1, imageFolderDefault2, imageFolderDefault3, imageFolderDefault4};
            Debug.Assert(defaultRadioButtons.Length == NumberOfPictureSet);
            imageFolderList = new[]{imageFoldersList1, imageFoldersList2, imageFoldersList3, imageFoldersList4};
            Debug.Assert(imageFolderList.Length == NumberOfPictureSet);

            // enable only there are more than 1 monitor.
            asMixedMode.IsEnabled = Screen.AllScreens.Length > 1;

            slideDelayInput.ValueChanged += delegate { enableButtons(true); };
            loadSettingsToUi();
            enableButtons(false);
        }
        #endregion
        protected override void OnSourceInitialized(EventArgs e) {
            base.OnSourceInitialized(e);
            glassMaker = new GlassHelper(this, new Thickness(-1));
            glassMaker.ExtendGlassFrame();
        }
        ListView currentFolderListView{
            get{
                var index = imageFolderTab.SelectedIndex;
                Debug.Assert(index > 0);
                return imageFolderList[index];
            }
        }
        FolderCollection currentFolderList{
            get{
                var index = imageFolderTab.SelectedIndex;
                Debug.Assert(index > 0);
                return folderSet[index];
            }
        }
        #region Save/Restore Settings
        void loadSettingsToUi(){
            slideDelayInput.Value = Settings.Default.SlideShowDelay;
            slideModeList.SelectedItem = Settings.Default.SlideMode;
            displayModeList.SelectedItem = Settings.Default.DisplayMode;
            folderDialog.SelectedPath = Settings.Default.LastSelectedFolder;

            folderSet = Settings.Default.PicturePaths ?? new FolderCollectionSet();
            folderSet.SelectedIndex = Settings.Default.PictureSetSelected;
            for(int setIndex=0; setIndex < NumberOfPictureSet; ++setIndex)
                if (setIndex >= folderSet.Count)
                    folderSet.Add(new FolderCollection());
                else
                    foreach(var item in folderSet[setIndex])
                        imageFolderList[setIndex].Items.Add(item);
            Debug.Assert(folderSet.SelectedIndex < NumberOfPictureSet);
            defaultRadioButtons[folderSet.SelectedIndex].IsChecked = true;

            loadUiSaverMode(Settings.Default.SaverMode);
            backgroundPicture.Text = Settings.Default.BackgroundPicturePath;
        }
        void loadUiSaverMode(SaverMode mode){
            switch (mode){
            case SaverMode.SlideShow:
                asSlideShowMode.IsChecked = true;
                break;
            case SaverMode.PhotoCollage:
                asPhotoCollageMode.IsChecked = true;
                break;
            case SaverMode.Mixed:
                asMixedMode.IsChecked = true;
                break;
            default:
                asSlideShowMode.IsChecked = true;
                Debug.Write("Saver mode ");
                Debug.Write(Settings.Default.SaverMode);
                Debug.WriteLine(" is not handled!!");
                break;
            }
        }
        void storeUiToSettings(){
            var defaultSetIndex = Array.FindIndex(defaultRadioButtons, radio => radio.IsChecked != null && radio.IsChecked.Value);
            Debug.Assert(defaultSetIndex != -1);

            folderSet.SelectedIndex = defaultSetIndex;

            Settings.Default.SlideShowDelay = (int) slideDelayInput.Value;
            Settings.Default.SlideMode = (SlideMode) slideModeList.SelectedItem;
            Settings.Default.DisplayMode = (DisplayMode) displayModeList.SelectedItem;
            Settings.Default.PicturePaths = folderSet;
            Settings.Default.LastSelectedFolder = folderDialog.SelectedPath;
            Settings.Default.SaverMode = (bool) asSlideShowMode.IsChecked
                                             ? SaverMode.SlideShow
                                             : (bool) asPhotoCollageMode.IsChecked ? SaverMode.PhotoCollage : SaverMode.Mixed;
            Settings.Default.PictureSetSelected = folderSet.SelectedIndex;
            Settings.Default.BackgroundPicturePath = backgroundPicture.Text;
        }
        #endregion

        void enableButtons(bool enable){
            if (okButton != null)
                okButton.IsEnabled = enable;
        }
        void selectAndAddFolder(InclusionMode mode){
            if (folderDialog.ShowDialog(new Winform32Helper(this)) == System.Windows.Forms.DialogResult.OK){
                if (!currentFolderList.Contains(folderDialog.SelectedPath)){
                    var folder = currentFolderList.Add(folderDialog.SelectedPath, mode);
                    currentFolderListView.Items.Add(folder);
                }
                enableButtons(true);
            }
        }

        #region Event Handlers

        void onClearList(object sender, RoutedEventArgs e){
            if (currentFolderList.Count > 0
                && MessageBox.Show("Are you sure to clear the list?", "Clear folder list",
                    MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes){
                currentFolderListView.Items.Clear();
                currentFolderList.Clear();
                enableButtons(true);
            }
        }
        void onContentChanged(object sender,RoutedEventArgs e) {
            Debug.WriteLine("Event:" + e + ", Source=" + e.Source);
            var selectionArg = e as SelectionChangedEventArgs;
            enableButtons(selectionArg == null || selectionArg.RemovedItems.Count > 0);
            if (selectionArg != null){
                Debug.WriteLine("Add Items = " + selectionArg.AddedItems.Count);
                if (selectionArg.AddedItems.Count > 0)
                    Debug.WriteLine("\tFirst Item: " + selectionArg.AddedItems[0]);
                Debug.WriteLine("Remove Items = " + selectionArg.RemovedItems.Count);
                if (selectionArg.RemovedItems.Count > 0)
                    Debug.WriteLine("\tFirst Item: " + selectionArg.RemovedItems[0]);
            }
        }
        void onSave(object sender, RoutedEventArgs e){
            storeUiToSettings();
            Settings.Default.Save();
            DialogResult = true;
        }
        void onAddExcludedFolder(object sender, RoutedEventArgs e){
            selectAndAddFolder(InclusionMode.Exclude);
        }
        void onAddSingleFolder(object sender, RoutedEventArgs e){
            selectAndAddFolder(InclusionMode.Single);
        }
        void onAddRecursiveFolder(object sender, RoutedEventArgs e){
            selectAndAddFolder(InclusionMode.Recursive);
        }
        void onKeyPressedInGrid(object sender, KeyEventArgs e){
            if (e.Key == Key.Delete && currentFolderListView.SelectedItems.Count > 0){
                e.Handled = true;
                var selectedFolders = currentFolderListView.SelectedItems.CastToArray<FolderInclusion>();
                foreach (FolderInclusion folder in selectedFolders){
                    currentFolderListView.Items.Remove(folder);
                    currentFolderList.Remove(folder);
                }
                enableButtons(true);
            }
        }
        void onSelectBackground(object sender, RoutedEventArgs e){
            var fileDialog = new Microsoft.Win32.OpenFileDialog{
                                                   InitialDirectory = backgroundPicture.Text,
                                                   Title = "Browse background picture file",
                                                   CheckFileExists = true,
                                                   DefaultExt = "jpg",
                                                   Filter = "JPEG|*.jpg;*.jpeg|GIF|*.gif|PNG|*.png|Bitmap|*.bmp|TIFF|*.tiff|All supported files|*.jpg;*.jpeg;*.gif;*.png;*.bmp;*.tiff"
                                               };
            var result = fileDialog.ShowDialog();
            if ((bool)result && !fileDialog.FileName.Equals(backgroundPicture.Text, StringComparison.OrdinalIgnoreCase)){
                backgroundPicture.Text = fileDialog.FileName;
                enableButtons(true);
            }
        }
        void onTextChanged(object sender, TextChangedEventArgs e){
            enableButtons(true);
        }

        #endregion

        readonly RadioButton[] defaultRadioButtons;
        readonly ListView[] imageFolderList;
        FolderCollectionSet folderSet;
        GlassHelper glassMaker;
        readonly FolderBrowserDialog folderDialog = new FolderBrowserDialog{
                                                                               Description = "Select a folder containing any picture.",
                                                                               ShowNewFolderButton = false,
                                                                           };
        void onChangeSlideMode(object sender, SelectionChangedEventArgs e){
            Settings.Default.LastShownIndex = 0;
            onContentChanged(sender, e);
        }
    }
}