Re-factor PDFPrintServiceFactory to use import maps

This is very old code, which can (ever so slightly) be simplified now that import maps are available.

web/app.js

@@ -70,6 +70,7 @@ import { PDFHistory } from "./pdf_history.js";
 import { PDFLayerViewer } from "web-pdf_layer_viewer";
 import { PDFOutlineViewer } from "web-pdf_outline_viewer";
 import { PDFPresentationMode } from "web-pdf_presentation_mode";
+import { PDFPrintServiceFactory } from "web-print_service";
 import { PDFRenderingQueue } from "./pdf_rendering_queue.js";
 import { PDFScriptingManager } from "./pdf_scripting_manager.js";
 import { PDFSidebar } from "web-pdf_sidebar";
@@ -731,7 +732,7 @@ const PDFViewerApplication = {
   },
 
   get supportsPrinting() {
-    return PDFPrintServiceFactory.instance.supportsPrinting;
+    return PDFPrintServiceFactory.supportsPrinting;
   },
 
   get supportsFullscreen() {
@@ -1786,7 +1787,7 @@ const PDFViewerApplication = {
     const optionalContentConfigPromise =
       this.pdfViewer.optionalContentConfigPromise;
 
-    const printService = PDFPrintServiceFactory.instance.createPrintService(
+    const printService = PDFPrintServiceFactory.createPrintService(
       this.pdfDocument,
       pagesOverview,
       printContainer,
@@ -3234,14 +3235,4 @@ function webViewerReportTelemetry({ details }) {
   PDFViewerApplication.externalServices.reportTelemetry(details);
 }
 
-/* Abstract factory for the print service. */
-const PDFPrintServiceFactory = {
-  instance: {
-    supportsPrinting: false,
-    createPrintService() {
-      throw new Error("Not implemented: createPrintService");
-    },
-  },
-};
-
-export { PDFPrintServiceFactory, PDFViewerApplication };
+export { PDFViewerApplication };

web/firefox_print_service.js

@@ -20,7 +20,6 @@ import {
   shadow,
 } from "pdfjs-lib";
 import { getXfaHtmlForPrinting } from "./print_utils.js";
-import { PDFPrintServiceFactory } from "./app.js";
 
 // Creates a placeholder with div and canvas with right size for the page.
 function composePage(
@@ -194,15 +193,16 @@ class FirefoxPrintService {
   }
 }
 
-PDFPrintServiceFactory.instance = {
-  get supportsPrinting() {
+/**
+ * @implements {IPDFPrintServiceFactory}
+ */
+class PDFPrintServiceFactory {
+  static get supportsPrinting() {
     const canvas = document.createElement("canvas");
-    const value = "mozPrintCallback" in canvas;
+    return shadow(this, "supportsPrinting", "mozPrintCallback" in canvas);
+  }
 
-    return shadow(this, "supportsPrinting", value);
-  },
-
-  createPrintService(
+  static createPrintService(
     pdfDocument,
     pagesOverview,
     printContainer,
@@ -218,7 +218,7 @@ PDFPrintServiceFactory.instance = {
       optionalContentConfigPromise,
       printAnnotationStoragePromise
     );
-  },
-};
+  }
+}
 
-export { FirefoxPrintService };
+export { PDFPrintServiceFactory };

web/interfaces.js

@@ -217,4 +217,23 @@ class IL10n {
   resume() {}
 }
 
-export { IDownloadManager, IL10n, IPDFLinkService, IRenderableView };
+/**
+ * @interface
+ */
+class IPDFPrintServiceFactory {
+  static get supportsPrinting() {
+    return false;
+  }
+
+  static createPrintService() {
+    throw new Error("Not implemented: createPrintService");
+  }
+}
+
+export {
+  IDownloadManager,
+  IL10n,
+  IPDFLinkService,
+  IPDFPrintServiceFactory,
+  IRenderableView,
+};

web/pdf_print_service.js

@@ -13,9 +13,9 @@
  * limitations under the License.
  */
 
-import { AnnotationMode, PixelsPerInch } from "pdfjs-lib";
-import { PDFPrintServiceFactory, PDFViewerApplication } from "./app.js";
+import { AnnotationMode, PixelsPerInch, shadow } from "pdfjs-lib";
 import { getXfaHtmlForPrinting } from "./print_utils.js";
+import { PDFViewerApplication } from "./app.js";
 
 let activeService = null;
 let dialog = null;
@@ -355,10 +355,15 @@ function ensureOverlay() {
   return overlayPromise;
 }
 
-PDFPrintServiceFactory.instance = {
-  supportsPrinting: true,
+/**
+ * @implements {IPDFPrintServiceFactory}
+ */
+class PDFPrintServiceFactory {
+  static get supportsPrinting() {
+    return shadow(this, "supportsPrinting", true);
+  }
 
-  createPrintService(
+  static createPrintService(
     pdfDocument,
     pagesOverview,
     printContainer,
@@ -378,7 +383,7 @@ PDFPrintServiceFactory.instance = {
       printAnnotationStoragePromise
     );
     return activeService;
-  },
-};
+  }
+}
 
-export { PDFPrintService };
+export { PDFPrintServiceFactory };

web/viewer-geckoview.js

@@ -14,7 +14,6 @@
  */
 
 import "web-com";
-import "web-print_service";
 import { RenderingStates, ScrollMode, SpreadMode } from "./ui_utils.js";
 import { AppOptions } from "./app_options.js";
 import { LinkTarget } from "./pdf_link_service.js";

web/viewer.js

@@ -14,7 +14,6 @@
  */
 
 import "web-com";
-import "web-print_service";
 import { RenderingStates, ScrollMode, SpreadMode } from "./ui_utils.js";
 import { AppOptions } from "./app_options.js";
 import { LinkTarget } from "./pdf_link_service.js";