Add a new pdfjs.enablePermissions preference, off by default, to allow the PDF documents to disable copying in the viewer (bug 792816)

extensions/chromium/preferences_schema.json

@@ -151,6 +151,10 @@
       "type": "boolean",
       "default": false
     },
+    "enablePermissions": {
+      "type": "boolean",
+      "default": false
+    },
     "historyUpdateUrl": {
       "type": "boolean",
       "default": false

web/app.js

@@ -48,6 +48,7 @@ import {
   MissingPDFException,
   OPS,
   PDFWorker,
+  PermissionFlag,
   shadow,
   UnexpectedResponseException,
   UNSUPPORTED_FEATURES,
@@ -77,6 +78,7 @@ const DEFAULT_SCALE_DELTA = 1.1;
 const DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT = 5000; // ms
 const FORCE_PAGES_LOADED_TIMEOUT = 10000; // ms
 const WHEEL_ZOOM_DISABLED_TIMEOUT = 1000; // ms
+const ENABLE_PERMISSIONS_CLASS = "enablePermissions";
 
 const ViewOnLoad = {
   UNKNOWN: -1,
@@ -679,6 +681,7 @@ const PDFViewerApplication = {
       this.pdfLinkService.setDocument(null);
       this.pdfDocumentProperties.setDocument(null);
     }
+    webViewerResetPermissions();
     this.store = null;
     this.isInitialViewSet = false;
     this.downloadComplete = false;
@@ -1149,6 +1152,10 @@ const PDFViewerApplication = {
             pdfViewer.focus();
           }
 
+          // Currently only the "copy"-permission is supported, hence we delay
+          // the `getPermissions` API call until *after* rendering has started.
+          this._initializePermissions(pdfDocument);
+
           // For documents with different page sizes, once all pages are
           // resolved, ensure that the correct location becomes visible on load.
           // (To reduce the risk, in very large and/or slow loading documents,
@@ -1467,6 +1474,24 @@ const PDFViewerApplication = {
     }
   },
 
+  /**
+   * @private
+   */
+  async _initializePermissions(pdfDocument) {
+    const permissions = await pdfDocument.getPermissions();
+
+    if (pdfDocument !== this.pdfDocument) {
+      return; // The document was closed while the permissions resolved.
+    }
+    if (!permissions || !AppOptions.get("enablePermissions")) {
+      return;
+    }
+    // Currently only the "copy"-permission is supported.
+    if (!permissions.includes(PermissionFlag.COPY)) {
+      this.appConfig.viewerContainer.classList.add(ENABLE_PERMISSIONS_CLASS);
+    }
+  },
+
   setInitialView(
     storedHash,
     { rotation, sidebarView, scrollMode, spreadMode } = {}
@@ -1979,6 +2004,15 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
   };
 }
 
+function webViewerResetPermissions() {
+  const { appConfig } = PDFViewerApplication;
+  if (!appConfig) {
+    return;
+  }
+  // Currently only the "copy"-permission is supported.
+  appConfig.viewerContainer.classList.remove(ENABLE_PERMISSIONS_CLASS);
+}
+
 function webViewerPageRendered(evt) {
   const pageNumber = evt.pageNumber;
   const pageIndex = pageNumber - 1;

web/app_options.js

@@ -53,6 +53,11 @@ const defaultOptions = {
     value: false,
     kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
   },
+  enablePermissions: {
+    /** @type {boolean} */
+    value: false,
+    kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
+  },
   /**
    * The `disablePreferences` is, conditionally, defined below.
    */

web/viewer.css

@@ -55,6 +55,11 @@ select {
   display: none !important;
 }
 
+.pdfViewer.enablePermissions .textLayer > span {
+  user-select: none !important;
+  cursor: not-allowed;
+}
+
 #viewerContainer.pdfPresentationMode:-ms-fullscreen {
   top: 0px !important;
   overflow: hidden !important;