Break import cycles, in the viewer, for PDFViewerApplication

Currently the `web/app.js` file pulls in various build-specific dependencies, via the use of import maps, and those files in turn import from `web/app.js` thus creating undesirable import cycles.
To avoid this we instead pass in a `PDFViewerApplication`-reference, immediately after it's been created, to the relevant code.

Note that we use an ESLint plugin rule, see `import/no-cycle`, that is normally able to catch import cycles. However, in this case import maps are involved which is why this wasn't caught.

web/app.js

@@ -53,12 +53,12 @@ import {
 } from "pdfjs-lib";
 import { AppOptions, OptionKind } from "./app_options.js";
 import { AutomationEventBus, EventBus } from "./event_utils.js";
+import { ExternalServices, initCom } from "web-external_services";
 import { LinkTarget, PDFLinkService } from "./pdf_link_service.js";
 import { AltTextManager } from "web-alt_text_manager";
 import { AnnotationEditorParams } from "web-annotation_editor_params";
 import { CaretBrowsingMode } from "./caret_browsing.js";
 import { DownloadManager } from "web-download_manager";
-import { ExternalServices } from "web-external_services";
 import { OverlayManager } from "./overlay_manager.js";
 import { PasswordPrompt } from "./password_prompt.js";
 import { PDFAttachmentViewer } from "web-pdf_attachment_viewer";
@@ -2146,6 +2146,12 @@ const PDFViewerApplication = {
   },
 };
 
+initCom(PDFViewerApplication);
+
+if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
+  PDFPrintServiceFactory.initGlobals(PDFViewerApplication);
+}
+
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
   const HOSTED_VIEWER_ORIGINS = [
     "null",

web/chromecom.js

@@ -19,7 +19,6 @@ import { BaseExternalServices } from "./external_services.js";
 import { BasePreferences } from "./preferences.js";
 import { GenericL10n } from "./genericl10n.js";
 import { GenericScripting } from "./generic_scripting.js";
-import { PDFViewerApplication } from "./app.js";
 
 if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("CHROME")) {
   throw new Error(
@@ -42,10 +41,16 @@ if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("CHROME")) {
   }
 
   AppOptions.set("defaultUrl", defaultUrl);
+})();
+
+let viewerApp = { initialized: false };
+function initCom(app) {
+  viewerApp = app;
+
   // Ensure that PDFViewerApplication.initialBookmark reflects the current hash,
   // in case the URL rewrite above results in a different hash.
-  PDFViewerApplication.initialBookmark = location.hash.slice(1);
+  viewerApp.initialBookmark = location.hash.slice(1);
-})();
+}
 
 const ChromeCom = {
   /**
@@ -77,10 +82,9 @@ const ChromeCom = {
    * Resolves a PDF file path and attempts to detects length.
    *
    * @param {string} file - Absolute URL of PDF file.
-   * @param {OverlayManager} overlayManager - Manager for the viewer overlays.
    * @param {Function} callback - A callback with resolved URL and file length.
    */
-  resolvePDFFile(file, overlayManager, callback) {
+  resolvePDFFile(file, callback) {
     // Expand drive:-URLs to filesystem URLs (Chrome OS)
     file = file.replace(
       /^drive:/i,
@@ -104,13 +108,9 @@ const ChromeCom = {
         // Even without this check, the file load in frames is still blocked,
         // but this may change in the future (https://crbug.com/550151).
         if (origin && !/^file:|^chrome-extension:/.test(origin)) {
-          PDFViewerApplication._documentError(
+          viewerApp._documentError(
-            "Blocked " +
+            `Blocked ${origin} from loading ${file}. Refused to load ` +
-              origin +
+              "a local file in a non-local page for security reasons."
-              " from loading " +
-              file +
-              ". Refused to load a local file in a non-local page " +
-              "for security reasons."
           );
           return;
         }
@@ -118,7 +118,7 @@ const ChromeCom = {
           if (isAllowedAccess) {
             callback(file);
           } else {
-            requestAccessToLocalFile(file, overlayManager, callback);
+            requestAccessToLocalFile(file, viewerApp.overlayManager, callback);
           }
         });
       });
@@ -420,7 +420,6 @@ class ExternalServices extends BaseExternalServices {
     // defaultUrl is set in viewer.js
     ChromeCom.resolvePDFFile(
       AppOptions.get("defaultUrl"),
-      PDFViewerApplication.overlayManager,
       function (url, length, originalUrl) {
         callbacks.onOpenWithURL(url, length, originalUrl);
       }
@@ -436,4 +435,4 @@ class ExternalServices extends BaseExternalServices {
   }
 }
 
-export { ChromeCom, ExternalServices, Preferences };
+export { ExternalServices, initCom, Preferences };

web/firefoxcom.js

@@ -18,7 +18,6 @@ import { BaseExternalServices } from "./external_services.js";
 import { BasePreferences } from "./preferences.js";
 import { DEFAULT_SCALE_VALUE } from "./ui_utils.js";
 import { L10n } from "./l10n.js";
-import { PDFViewerApplication } from "./app.js";
 
 if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
   throw new Error(
@@ -26,6 +25,11 @@ if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
   );
 }
 
+let viewerApp = { initialized: false };
+function initCom(app) {
+  viewerApp = app;
+}
+
 class FirefoxCom {
   /**
    * Creates an event that the extension is listening for and will
@@ -167,14 +171,14 @@ class Preferences extends BasePreferences {
   const findLen = "find".length;
 
   const handleEvent = function ({ type, detail }) {
-    if (!PDFViewerApplication.initialized) {
+    if (!viewerApp.initialized) {
       return;
     }
     if (type === "findbarclose") {
-      PDFViewerApplication.eventBus.dispatch(type, { source: window });
+      viewerApp.eventBus.dispatch(type, { source: window });
       return;
     }
-    PDFViewerApplication.eventBus.dispatch("find", {
+    viewerApp.eventBus.dispatch("find", {
       source: window,
       type: type.substring(findLen),
       query: detail.query,
@@ -194,18 +198,18 @@ class Preferences extends BasePreferences {
 (function listenZoomEvents() {
   const events = ["zoomin", "zoomout", "zoomreset"];
   const handleEvent = function ({ type, detail }) {
-    if (!PDFViewerApplication.initialized) {
+    if (!viewerApp.initialized) {
       return;
     }
     // Avoid attempting to needlessly reset the zoom level *twice* in a row,
     // when using the `Ctrl + 0` keyboard shortcut.
     if (
       type === "zoomreset" &&
-      PDFViewerApplication.pdfViewer.currentScaleValue === DEFAULT_SCALE_VALUE
+      viewerApp.pdfViewer.currentScaleValue === DEFAULT_SCALE_VALUE
     ) {
       return;
     }
-    PDFViewerApplication.eventBus.dispatch(type, { source: window });
+    viewerApp.eventBus.dispatch(type, { source: window });
   };
 
   for (const event of events) {
@@ -215,10 +219,10 @@ class Preferences extends BasePreferences {
 
 (function listenSaveEvent() {
   const handleEvent = function ({ type, detail }) {
-    if (!PDFViewerApplication.initialized) {
+    if (!viewerApp.initialized) {
       return;
     }
-    PDFViewerApplication.eventBus.dispatch("download", { source: window });
+    viewerApp.eventBus.dispatch("download", { source: window });
   };
 
   window.addEventListener("save", handleEvent);
@@ -226,10 +230,10 @@ class Preferences extends BasePreferences {
 
 (function listenEditingEvent() {
   const handleEvent = function ({ detail }) {
-    if (!PDFViewerApplication.initialized) {
+    if (!viewerApp.initialized) {
       return;
     }
-    PDFViewerApplication.eventBus.dispatch("editingaction", {
+    viewerApp.eventBus.dispatch("editingaction", {
       source: window,
       name: detail.name,
     });
@@ -242,9 +246,9 @@ if (PDFJSDev.test("GECKOVIEW")) {
   (function listenQueryEvents() {
     window.addEventListener("pdf.js.query", async ({ detail: { queryId } }) => {
       let result = null;
-      if (queryId === "canDownloadInsteadOfPrint") {
+      if (viewerApp.initialized && queryId === "canDownloadInsteadOfPrint") {
         result = false;
-        const { pdfDocument, pdfViewer } = PDFViewerApplication;
+        const { pdfDocument, pdfViewer } = viewerApp;
         if (pdfDocument) {
           try {
             const hasUnchangedAnnotations =
@@ -411,4 +415,4 @@ class ExternalServices extends BaseExternalServices {
   }
 }
 
-export { DownloadManager, ExternalServices, FirefoxCom, Preferences };
+export { DownloadManager, ExternalServices, initCom, Preferences };

web/genericcom.js

@@ -25,7 +25,7 @@ if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("GENERIC")) {
   );
 }
 
-const GenericCom = {};
+function initCom(app) {}
 
 class Preferences extends BasePreferences {
   async _writeToStorage(prefObj) {
@@ -47,4 +47,4 @@ class ExternalServices extends BaseExternalServices {
   }
 }
 
-export { ExternalServices, GenericCom, Preferences };
+export { ExternalServices, initCom, Preferences };

web/interfaces.js

@@ -221,6 +221,8 @@ class IL10n {
  * @interface
  */
 class IPDFPrintServiceFactory {
+  static initGlobals() {}
+
   static get supportsPrinting() {
     return false;
   }

web/pdf_print_service.js

@@ -15,11 +15,11 @@
 
 import { AnnotationMode, PixelsPerInch, shadow } from "pdfjs-lib";
 import { getXfaHtmlForPrinting } from "./print_utils.js";
-import { PDFViewerApplication } from "./app.js";
 
 let activeService = null;
 let dialog = null;
 let overlayManager = null;
+let viewerApp = { initialized: false };
 
 // Renders the page to the canvas of the given print service, and returns
 // the suggested dimensions of the output page.
@@ -338,7 +338,7 @@ function ensureOverlay() {
     );
   }
   if (!overlayPromise) {
-    overlayManager = PDFViewerApplication.overlayManager;
+    overlayManager = viewerApp.overlayManager;
     if (!overlayManager) {
       throw new Error("The overlay manager has not yet been initialized.");
     }
@@ -359,6 +359,10 @@ function ensureOverlay() {
  * @implements {IPDFPrintServiceFactory}
  */
 class PDFPrintServiceFactory {
+  static initGlobals(app) {
+    viewerApp = app;
+  }
+
   static get supportsPrinting() {
     return shadow(this, "supportsPrinting", true);
   }