Implement export to pptx using JS pptxgenjs library.

src/include/ipebase.h

@@ -287,6 +287,7 @@ class Stream {
     Stream & operator<<(double d);
     void putHexByte(char b);
     void putXmlString(String s);
+    void putJsonString(String s);
 };
 
 /*! \class ipe::TellStream

src/include/ipeutils.h

@@ -91,13 +91,14 @@ class A85Stream : public Stream {
 
 class Base64Stream : public Stream {
 public:
-    Base64Stream(Stream & stream);
+    Base64Stream(Stream & stream, bool noLineBreaks = false);
     virtual void putChar(char ch);
     virtual void close();
 
 private:
     Stream & iStream;
     uint8_t iCh[3];
+    int iNoLineBreaks;
     int iN;
     int iCol;
 };

src/ipe-web/index.html

@@ -163,8 +163,9 @@ <h3 id="modal-header-content"></h3>
           <div id="filedialog-label">Enter filename</div>
           <input id="filename" />
           <div id="directory"></div>
-          <div id="filedialog-error">The filename must not contain a slash (<tt>/</tt>) and must have
-          one of the following extensions: <tt>ipe pdf isy png jpg svg lua</tt></div>
+          <div id="filedialog-error">The filename must not contain a
+          slash (<tt>/</tt>) and must have one of the following extensions:
+	    <tt>ipe pdf isy png jpg svg lua pptx</tt></div>
           <div id="filedialog-upload">
             Or upload a file:
             <input id="upload" type="file" />

src/ipe-web/package.json

@@ -25,6 +25,8 @@
   },
   "dependencies": {
     "@melloware/coloris": "^0.24.0",
-    "sortablejs": "^1.15.3"
+    "sortablejs": "^1.15.3",
+    "jszip": "^3.10.2",
+    "pptxgenjs": "^4.0.1"
   }
 }

src/ipe-web/src/ipe/ipeui.ts

@@ -90,6 +90,13 @@ export class IpeUi {
 	externalConfiguration = "";
 	private internalConfiguration = "";
 	private _presentationWindow: Window | null = null;
+	_createSlides:
+		| ((
+				jsonData: string,
+				textConversion: string,
+				titleConversion: string,
+		  ) => Promise<Uint8Array>)
+		| null = null;
 
 	constructor(
 		ipe: Ipe,
@@ -708,6 +715,7 @@ export class IpeUi {
 					"tablet_hints",
 					"undo",
 					"redo",
+					"export_pptx",
 				].includes(name)
 			)
 				return;
@@ -1247,4 +1255,24 @@ export class IpeUi {
 			}
 		}
 	}
+
+	async createSlides(
+		jsonFn: string,
+		outFn: string,
+		textConversion: string,
+		titleConversion: string,
+	): Promise<void> {
+		if (this._createSlides) {
+			const jsonData = window.ipeui.ipe.FS.readFile(jsonFn, {
+				encoding: "utf8",
+			});
+			const data = await this._createSlides(
+				jsonData,
+				textConversion,
+				titleConversion,
+			);
+			window.ipeui.ipe.FS.writeFile(outFn, data);
+			window.ipeui.modal.fileManager();
+		}
+	}
 }

src/ipe-web/src/ipe/modal.ts

@@ -14,7 +14,12 @@ import "./modal.css";
 import Sortable from "sortablejs";
 import type { PopupMenu, PopupMenuResults } from "./popup-menu";
 
-type Directory = "documents" | "images" | "styles" | "ipelets";
+type Directory =
+	| "documents"
+	| "images"
+	| "styles"
+	| "ipelets"
+	| "presentations";
 
 interface FileType {
 	dir: Directory;
@@ -30,6 +35,12 @@ const knownFileTypes: { [ext: string]: FileType } = {
 	svg: { dir: "images", mimeType: "image/svg+xml" },
 	isy: { dir: "styles", mimeType: "application/xml" },
 	lua: { dir: "ipelets", mimeType: "text/plain" },
+	html: { dir: "presentations", mimeType: "text/html" },
+	pptx: {
+		dir: "presentations",
+		mimeType:
+			"application/vnd.openxmlformats-officedocument.presentationml.presentation",
+	},
 };
 
 type ResumeCallback = (result: ResumeResult, threadRef: number) => void;
@@ -58,8 +69,9 @@ export interface PageSelectorItem {
 function dirFromOptions(options: FileDialogOptions): Directory {
 	const f = options.filters[0];
 	if (f.includes("*.ipe")) return "documents";
-	if (f.includes("*.isy")) return "styles";
+	if (f.includes("*.isy") || f === "reveal.htmljs") return "styles";
 	if (f.includes("*.lua")) return "ipelets";
+	if (f.includes("*.html") || f.includes("*.pptx")) return "presentations";
 	return "images";
 }