Replacing the default Dialogs

Ines works on a desktop WPF application for a mid-sized European wealth-management firm. The whole app is themed in the firm's navy-and-gold corporate palette, with custom WPF window chrome and the firm's typography. Every dialog has been carefully restyled -- except one.

The HTML editor's Insert Image dialog still looked like it came from a Windows Forms app from 2010. Her compliance reviewer flagged it: "This dialog doesn't match the rest of the application. Please bring it in line before the next audit."

Ines opened the API reference and found that every customer-replaceable dialog on the WPF editor is defined as an interface in SpiceLogic.HtmlEditor.WPF.Models.Dialogs. There are nine she could swap: IImageDialog, IHyperlinkDialog, ITableDialog, ITableCellDialog, ISearchDialog, ISpellCheckerDialog, ISymbolDialog, IStyleBuilderDialog, and IYouTubeVideoInsertDialog. (The color picker is also replaceable through IColorPickerDialog if you want a custom palette.)

She didn't want to rebuild the dialog from scratch. The good news: the product ships the full source of every default dialog inside the installation folder under Source\\DialogSamples\\WPF. Ines copied the default image dialog XAML into her project, restyled it with her firm's ResourceDictionary, and was done with the visual work in an afternoon.

Plugging the new dialog into the editor was a single line per dialog. Each dialog has a matching CreateXxxDialogMethod factory delegate on IDialogService. The editor calls her factory whenever it needs that dialog:

using SpiceLogic.HtmlEditor.WPF.Models.Dialogs;



public partial class MainWindow : Window

{

    public MainWindow()

    {

        InitializeComponent();



        editor.Dialog.CreateImageDialogMethod      = () => new BrandedImageDialog();

        editor.Dialog.CreateHyperlinkDialogMethod  = () => new BrandedHyperlinkDialog();

        editor.Dialog.CreateTableDialogMethod      = () => new BrandedTableDialog();

        editor.Dialog.CreateSearchDialogMethod     = () => new BrandedSearchDialog();

    }

}

Because she had inherited from the default code, her BrandedImageDialog already implemented IImageDialog and inherited from Window. The editor sets the input properties on the dialog, calls ShowDialog(), and reads the result properties back -- exactly the contract the interface promises.

One last touch she discovered while testing: by default the dialogs opened center-screen instead of center-of-app. Setting OwnerWindow on the dialog service fixed the parenting so every dialog the editor opens centers over her main window:

editor.Dialog.OwnerWindow = this; // "this" is the host Window

The compliance review passed on the first try. Ines marked the ticket done with a note: "Nine interfaces, one afternoon, full source as a starting point."