Preserve QPowerPoint subtitle lists in PPTX

src/io/powerPointOffice.ts

@@ -1,4 +1,4 @@
-import type { Slide, SlideImage } from "../types";
+import type { Slide, SlideImage, SlideListStyle } from "../types";
 import { officeTitleFromFileName, PPTX_MIME_TYPE, readOfficeFileAsArrayBuffer } from "./fileHelpers";
 
 export interface ImportedPowerPointDeck {
@@ -13,6 +13,7 @@ export interface ExportablePowerPointDeck {
 
 interface SlideTextBlock {
   text: string;
+  listStyle?: SlideListStyle;
   color?: string;
   fontSize?: number;
   fontFamily?: string;
@@ -77,6 +78,10 @@ export async function importPptxFile(file: File): Promise<ImportedPowerPointDeck
       const backgroundColor = slideBackgroundColor(parsedSlide);
       const hidden = slideHidden(parsedSlide);
       const transition = slideTransition(parsedSlide);
+      const subtitleListStyle = slideTextBlocks
+        .slice(1)
+        .map((block) => block.listStyle)
+        .find((style): style is SlideListStyle => Boolean(style));
 
       return {
         id: `pptx-slide-${index}`,
@@ -93,6 +98,7 @@ export async function importPptxFile(file: File): Promise<ImportedPowerPointDeck
         ...(slideTextBlocks[1]?.color ? { subtitleColor: slideTextBlocks[1].color } : {}),
         ...(slideTextBlocks[1]?.fontSize ? { subtitleFontSize: slideTextBlocks[1].fontSize } : {}),
         ...(slideTextBlocks[1]?.fontFamily ? { subtitleFontFamily: slideTextBlocks[1].fontFamily } : {}),
+        ...(subtitleListStyle ? { subtitleListStyle } : {}),
         images
       };
     })
@@ -183,7 +189,9 @@ export async function exportPptxBlob(deck: ExportablePowerPointDeck): Promise<Bl
 
   const result = await pptx.write({ outputType: "blob" });
   const blob = result instanceof Blob ? result : new Blob([result], { type: PPTX_MIME_TYPE });
-  return deck.slides.some((slide) => slide.hidden || slide.transition) ? applySlideXmlOverridesToPptxBlob(blob, deck.slides) : blob;
+  return deck.slides.some((slide) => slide.hidden || slide.transition || slide.subtitleListStyle)
+    ? applySlideXmlOverridesToPptxBlob(blob, deck.slides)
+    : blob;
 }
 
 export function extractTextBlocks(xmlNode: unknown): string[] {
@@ -202,11 +210,13 @@ function extractSlideTextBlocks(slideXml: unknown): SlideTextBlock[] {
       }
 
       const runProperties = firstRecordByKey(textBody, "rPr");
+      const listStyle = textBodyListStyle(textBody);
       const color = runTextColor(runProperties);
       const fontSize = runTextFontSize(runProperties);
       const fontFamily = runTextFontFamily(runProperties);
       return {
         text,
+        ...(listStyle ? { listStyle } : {}),
         ...(color ? { color } : {}),
         ...(fontSize ? { fontSize } : {}),
         ...(fontFamily ? { fontFamily } : {})
@@ -228,6 +238,26 @@ function mergeOrderedSlideTextBlocks(styledBlocks: SlideTextBlock[], orderedText
   });
 }
 
+function textBodyListStyle(textBody: Record<string, unknown>): SlideListStyle | undefined {
+  const paragraphStyles = toArray(textBody.p)
+    .map(paragraphListStyle)
+    .filter((style): style is SlideListStyle => Boolean(style));
+
+  return paragraphStyles.includes("number") ? "number" : paragraphStyles[0];
+}
+
+function paragraphListStyle(paragraph: unknown): SlideListStyle | undefined {
+  const paragraphProperties = childRecord(asRecord(paragraph), "pPr");
+  if (Object.keys(childRecord(paragraphProperties, "buAutoNum")).length > 0) {
+    return "number";
+  }
+  if (Object.keys(childRecord(paragraphProperties, "buChar")).length > 0) {
+    return "bullet";
+  }
+
+  return undefined;
+}
+
 function extractOrderedTextBodyTexts(xmlNode: unknown) {
   return orderedElementsByName(xmlNode, "txBody").map(orderedTextBodyText).filter(Boolean);
 }
@@ -482,7 +512,7 @@ async function applySlideXmlOverridesToPptxBlob(blob: Blob, slides: Slide[]) {
   const zip = await JSZip.loadAsync(await blob.arrayBuffer());
   await Promise.all(
     slides.map(async (slide, index) => {
-      if (!slide.hidden && !slide.transition) {
+      if (!slide.hidden && !slide.transition && !slide.subtitleListStyle) {
         return;
       }
 
@@ -499,7 +529,8 @@ async function applySlideXmlOverridesToPptxBlob(blob: Blob, slides: Slide[]) {
 
 function pptxSlideXmlWithOverrides(xml: string, slide: Slide) {
   const withHiddenState = slide.hidden ? pptxSlideXmlWithHiddenState(xml) : xml;
-  return slide.transition ? pptxSlideXmlWithTransition(withHiddenState, slide.transition) : withHiddenState;
+  const withTransition = slide.transition ? pptxSlideXmlWithTransition(withHiddenState, slide.transition) : withHiddenState;
+  return slide.subtitleListStyle ? pptxSlideXmlWithSubtitleList(withTransition, slide.subtitleListStyle) : withTransition;
 }
 
 function pptxSlideXmlWithHiddenState(xml: string) {
@@ -524,6 +555,37 @@ function pptxSlideXmlWithTransition(xml: string, transition: NonNullable<Slide["
   return xml.replace(/<p:sld\b[^>]*>/, (match) => `${match}${transitionXml}`);
 }
 
+function pptxSlideXmlWithSubtitleList(xml: string, listStyle: SlideListStyle) {
+  let textBodyIndex = 0;
+  return xml.replace(/<p:txBody\b[\s\S]*?<\/p:txBody>/g, (textBodyXml) => {
+    textBodyIndex += 1;
+    return textBodyIndex === 2 ? pptxTextBodyXmlWithList(textBodyXml, listStyle) : textBodyXml;
+  });
+}
+
+function pptxTextBodyXmlWithList(textBodyXml: string, listStyle: SlideListStyle) {
+  return textBodyXml.replace(/<a:p>[\s\S]*?<\/a:p>/g, (paragraphXml) => pptxParagraphXmlWithList(paragraphXml, listStyle));
+}
+
+function pptxParagraphXmlWithList(paragraphXml: string, listStyle: SlideListStyle) {
+  const listXml = pptxParagraphListXml(listStyle);
+  if (/<a:pPr\b[^>]*\/>/.test(paragraphXml)) {
+    return paragraphXml.replace(/<a:pPr\b([^>]*)\/>/, `<a:pPr$1>${listXml}</a:pPr>`);
+  }
+  if (/<a:pPr\b/.test(paragraphXml)) {
+    return paragraphXml.replace(/<a:pPr\b([^>]*)>([\s\S]*?)<\/a:pPr>/, (_match, attributes: string, content: string) => {
+      const contentWithoutBullet = content.replace(/<a:bu[A-Za-z]+\b[^>]*\/>/g, "");
+      return `<a:pPr${attributes}>${listXml}${contentWithoutBullet}</a:pPr>`;
+    });
+  }
+
+  return paragraphXml.replace("<a:p>", `<a:p><a:pPr>${listXml}</a:pPr>`);
+}
+
+function pptxParagraphListXml(listStyle: SlideListStyle) {
+  return listStyle === "number" ? '<a:buAutoNum type="arabicPeriod"/>' : '<a:buChar char="•"/>';
+}
+
 function normalizeHexColor(value?: string) {
   const raw = value?.trim().replace(/^#/, "").toUpperCase() ?? "";
   return /^[0-9A-F]{6}$/.test(raw) ? raw : "";