From ff7f87fc213534b609b9230f5c96ae0443072a83 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 30 Jan 2026 15:51:22 +0100
Subject: [PATCH] Replace the `IPDFPrintServiceFactory` interface with an
 abstract `BasePrintServiceFactory` class

This should help reduce the maintenance burden of the code, since you no longer need to remember to update separate code when touching the different `PDFPrintServiceFactory` classes.
---
 web/app.js                   |  5 +----
 web/firefox_print_service.js | 10 +++++-----
 web/interfaces.js            | 17 +----------------
 web/pdf_print_service.js     | 13 +++++--------
 web/print_utils.js           | 20 +++++++++++++++++++-
 5 files changed, 31 insertions(+), 34 deletions(-)

diff --git a/web/app.js b/web/app.js
index 0cd978f3e..056f3fdcd 100644
--- a/web/app.js
+++ b/web/app.js
@@ -2456,10 +2456,7 @@ const PDFViewerApplication = {
 };
 
 initCom(PDFViewerApplication);
-
-if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
-  PDFPrintServiceFactory.initGlobals(PDFViewerApplication);
-}
+PDFPrintServiceFactory.initGlobals(PDFViewerApplication);
 
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
   const HOSTED_VIEWER_ORIGINS = new Set([
diff --git a/web/firefox_print_service.js b/web/firefox_print_service.js
index 2af9d8529..04b8921e4 100644
--- a/web/firefox_print_service.js
+++ b/web/firefox_print_service.js
@@ -19,7 +19,10 @@ import {
   RenderingCancelledException,
   shadow,
 } from "pdfjs-lib";
-import { getXfaHtmlForPrinting } from "./print_utils.js";
+import {
+  BasePrintServiceFactory,
+  getXfaHtmlForPrinting,
+} from "./print_utils.js";
 
 // Creates a placeholder with div and canvas with right size for the page.
 function composePage(
@@ -194,10 +197,7 @@ class FirefoxPrintService {
   }
 }
 
-/**
- * @implements {IPDFPrintServiceFactory}
- */
-class PDFPrintServiceFactory {
+class PDFPrintServiceFactory extends BasePrintServiceFactory {
   static get supportsPrinting() {
     const canvas = document.createElement("canvas");
     return shadow(this, "supportsPrinting", "mozPrintCallback" in canvas);
diff --git a/web/interfaces.js b/web/interfaces.js
index 83e0f6c96..c798eba3a 100644
--- a/web/interfaces.js
+++ b/web/interfaces.js
@@ -71,19 +71,4 @@ class IDownloadManager {
   download(data, url, filename) {}
 }
 
-/**
- * @interface
- */
-class IPDFPrintServiceFactory {
-  static initGlobals() {}
-
-  static get supportsPrinting() {
-    return false;
-  }
-
-  static createPrintService() {
-    throw new Error("Not implemented: createPrintService");
-  }
-}
-
-export { IDownloadManager, IPDFPrintServiceFactory, IRenderableView };
+export { IDownloadManager, IRenderableView };
diff --git a/web/pdf_print_service.js b/web/pdf_print_service.js
index c20f928a9..e6ecbd363 100644
--- a/web/pdf_print_service.js
+++ b/web/pdf_print_service.js
@@ -13,16 +13,16 @@
  * limitations under the License.
  */
 
-// eslint-disable-next-line max-len
-/** @typedef {import("./interfaces.js").IPDFPrintServiceFactory} IPDFPrintServiceFactory */
-
 import {
   AnnotationMode,
   PixelsPerInch,
   RenderingCancelledException,
   shadow,
 } from "pdfjs-lib";
-import { getXfaHtmlForPrinting } from "./print_utils.js";
+import {
+  BasePrintServiceFactory,
+  getXfaHtmlForPrinting,
+} from "./print_utils.js";
 
 let activeService = null;
 let dialog = null;
@@ -371,10 +371,7 @@ function ensureOverlay() {
   return overlayPromise;
 }
 
-/**
- * @implements {IPDFPrintServiceFactory}
- */
-class PDFPrintServiceFactory {
+class PDFPrintServiceFactory extends BasePrintServiceFactory {
   static initGlobals(app) {
     viewerApp = app;
   }
diff --git a/web/print_utils.js b/web/print_utils.js
index c97af4756..04c820de9 100644
--- a/web/print_utils.js
+++ b/web/print_utils.js
@@ -17,6 +17,24 @@ import { getXfaPageViewport, PixelsPerInch } from "pdfjs-lib";
 import { SimpleLinkService } from "./pdf_link_service.js";
 import { XfaLayerBuilder } from "./xfa_layer_builder.js";
 
+class BasePrintServiceFactory {
+  constructor() {
+    if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
+      throw new Error("Cannot initialize BasePrintServiceFactory.");
+    }
+  }
+
+  static initGlobals(app) {}
+
+  static get supportsPrinting() {
+    throw new Error("Not implemented: supportsPrinting");
+  }
+
+  static createPrintService(params) {
+    throw new Error("Not implemented: createPrintService");
+  }
+}
+
 function getXfaHtmlForPrinting(printContainer, pdfDocument) {
   const xfaHtml = pdfDocument.allXfaHtml;
   const linkService = new SimpleLinkService();
@@ -40,4 +58,4 @@ function getXfaHtmlForPrinting(printContainer, pdfDocument) {
   }
 }
 
-export { getXfaHtmlForPrinting };
+export { BasePrintServiceFactory, getXfaHtmlForPrinting };