Added PowerPoint templates to the Slide Assistant (#1055)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/PowerPoint/PresentationWriter.Sections.cs

@@ -0,0 +1,60 @@
+using P = DocumentFormat.OpenXml.Presentation;
+using P14 = DocumentFormat.OpenXml.Office2010.PowerPoint;
+
+namespace AIStudio.Tools.PowerPoint;
+
+internal static partial class PresentationWriter
+{
+    /// <summary>
+    /// The extension of the presentation which holds its sections, as PowerPoint 2010 introduced them.
+    /// </summary>
+    private const string SECTION_LIST_URI = "{521415D9-36F7-43E2-AB2F-B90AF26B5E84}";
+
+    private static void RemoveSections(P.Presentation presentation)
+    {
+        if (presentation.PresentationExtensionList is not { } extensions)
+            return;
+
+        foreach (var extension in extensions.Elements<P.PresentationExtension>().Where(candidate => candidate.Uri?.Value == SECTION_LIST_URI).ToList())
+            extension.Remove();
+    }
+
+    /// <summary>
+    /// Makes every chapter a section, so that the slide sorter of PowerPoint shows the outline.
+    /// </summary>
+    /// <remarks>
+    /// The slides before the first chapter, such as the title slide, form a section named after the
+    /// presentation. A deck without chapters gets no sections at all.
+    /// </remarks>
+    /// <param name="presentation">The presentation.</param>
+    /// <param name="template">The template, which names the template slides of the deck.</param>
+    /// <param name="presentationTitle">The title of the presentation, which names the section before the first chapter.</param>
+    /// <param name="slides">The slides of the deck, in the order they were written.</param>
+    /// <param name="slideIds">The IDs of these slides, in the same order.</param>
+    private static void WriteSections(P.Presentation presentation, PresentationTemplate template, string presentationTitle, IReadOnlyList<SlideSpec> slides, IReadOnlyList<uint> slideIds)
+    {
+        if (!slides.Any(slide => slide.StartsChapter))
+            return;
+
+        var sections = new P14.SectionList();
+        P14.SectionSlideIdList? currentSection = null;
+        for (var index = 0; index < slides.Count; index++)
+        {
+            var slide = slides[index];
+            if (currentSection is null || slide.StartsChapter)
+            {
+                var title = TitleOf(slide, template);
+                var name = slide.StartsChapter && title.Length > 0 ? title : presentationTitle;
+                currentSection = new P14.SectionSlideIdList();
+                sections.Append(new P14.Section(currentSection) { Name = name, Id = NewSectionId() });
+            }
+
+            currentSection.Append(new P14.SectionSlideIdListEntry { Id = slideIds[index] });
+        }
+
+        var extensions = presentation.PresentationExtensionList ??= new P.PresentationExtensionList();
+        extensions.InsertAt(new P.PresentationExtension(sections) { Uri = SECTION_LIST_URI }, 0);
+    }
+
+    private static string NewSectionId() => $"{{{Guid.NewGuid().ToString().ToUpperInvariant()}}}";
+}