[api-minor] Deprecate getGlobalEventBus and update the "viewer components" examples accordingly

To avoid outright breaking third-party usages of the "viewer components" the `getGlobalEventBus` functionality is left intact, but a deprecation message is printed if the function is invoked.

The various examples are updated to *explicitly* initialize an `EventBus` instance, and provide that when initializing the relevant viewer components.

web/app.js

@@ -18,7 +18,7 @@ import {
   animationStarted,
   AutoPrintRegExp,
   DEFAULT_SCALE_VALUE,
-  getGlobalEventBus,
+  EventBus,
   getPDFFileNameFromURL,
   isValidRotation,
   isValidScrollMode,
@@ -343,7 +343,7 @@ const PDFViewerApplication = {
 
     const eventBus =
       appConfig.eventBus ||
-      getGlobalEventBus(AppOptions.get("eventBusDispatchToDOM"));
+      new EventBus({ dispatchToDOM: AppOptions.get("eventBusDispatchToDOM") });
     this.eventBus = eventBus;
 
     const pdfRenderingQueue = new PDFRenderingQueue();

web/base_viewer.js

@@ -1088,17 +1088,20 @@ class BaseViewer {
    * @param {HTMLDivElement} textLayerDiv
    * @param {number} pageIndex
    * @param {PageViewport} viewport
+   * @param {boolean} enhanceTextSelection
+   * @param {EventBus} eventBus
    * @returns {TextLayerBuilder}
    */
   createTextLayerBuilder(
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false
+    enhanceTextSelection = false,
+    eventBus
   ) {
     return new TextLayerBuilder({
       textLayerDiv,
-      eventBus: this.eventBus,
+      eventBus,
       pageIndex,
       viewport,
       findController: this.isInPresentationMode ? null : this.findController,

web/interfaces.js

@@ -146,13 +146,15 @@ class IPDFTextLayerFactory {
    * @param {number} pageIndex
    * @param {PageViewport} viewport
    * @param {boolean} enhanceTextSelection
+   * @param {EventBus} eventBus
    * @returns {TextLayerBuilder}
    */
   createTextLayerBuilder(
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false
+    enhanceTextSelection = false,
+    eventBus
   ) {}
 }
 

web/pdf_find_bar.js

@@ -25,7 +25,7 @@ const MATCHES_COUNT_LIMIT = 1000;
  * is done by PDFFindController.
  */
 class PDFFindBar {
-  constructor(options, eventBus = getGlobalEventBus(), l10n = NullL10n) {
+  constructor(options, eventBus, l10n = NullL10n) {
     this.opened = false;
 
     this.bar = options.bar || null;
@@ -38,7 +38,7 @@ class PDFFindBar {
     this.findResultsCount = options.findResultsCount || null;
     this.findPreviousButton = options.findPreviousButton || null;
     this.findNextButton = options.findNextButton || null;
-    this.eventBus = eventBus;
+    this.eventBus = eventBus || getGlobalEventBus();
     this.l10n = l10n;
 
     // Add event listeners to the DOM elements.

web/pdf_find_controller.js

@@ -67,9 +67,9 @@ class PDFFindController {
   /**
    * @param {PDFFindControllerOptions} options
    */
-  constructor({ linkService, eventBus = getGlobalEventBus() }) {
+  constructor({ linkService, eventBus }) {
     this._linkService = linkService;
-    this._eventBus = eventBus;
+    this._eventBus = eventBus || getGlobalEventBus();
 
     this._reset();
     eventBus.on("findbarclose", this._onFindBarClose.bind(this));

web/pdf_page_view.js

@@ -444,7 +444,8 @@ class PDFPageView {
         textLayerDiv,
         this.id - 1,
         this.viewport,
-        this.textLayerMode === TextLayerMode.ENABLE_ENHANCE
+        this.textLayerMode === TextLayerMode.ENABLE_ENHANCE,
+        this.eventBus
       );
     }
     this.textLayer = textLayer;

web/pdf_viewer.component.js

@@ -21,12 +21,7 @@ import {
   DefaultTextLayerFactory,
   TextLayerBuilder,
 } from "./text_layer_builder.js";
-import {
-  EventBus,
-  getGlobalEventBus,
-  NullL10n,
-  ProgressBar,
-} from "./ui_utils.js";
+import { EventBus, NullL10n, ProgressBar } from "./ui_utils.js";
 import { PDFLinkService, SimpleLinkService } from "./pdf_link_service.js";
 import { DownloadManager } from "./download_manager.js";
 import { GenericL10n } from "./genericl10n.js";
@@ -41,9 +36,6 @@ const pdfjsVersion = PDFJSDev.eval("BUNDLE_VERSION");
 // eslint-disable-next-line no-unused-vars
 const pdfjsBuild = PDFJSDev.eval("BUNDLE_BUILD");
 
-// For backwards compatibility, ensure that events are re-dispatched to the DOM.
-getGlobalEventBus(/* dispatchToDOM = */ true);
-
 export {
   PDFViewer,
   PDFSinglePageViewer,

web/text_layer_builder.js

@@ -444,19 +444,22 @@ class DefaultTextLayerFactory {
    * @param {number} pageIndex
    * @param {PageViewport} viewport
    * @param {boolean} enhanceTextSelection
+   * @param {EventBus} eventBus
    * @returns {TextLayerBuilder}
    */
   createTextLayerBuilder(
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false
+    enhanceTextSelection = false,
+    eventBus
   ) {
     return new TextLayerBuilder({
       textLayerDiv,
       pageIndex,
       viewport,
       enhanceTextSelection,
+      eventBus,
     });
   }
 }

web/ui_utils.js

@@ -757,9 +757,8 @@ const animationStarted = new Promise(function(resolve) {
 });
 
 /**
- * Simple event bus for an application. Listeners are attached using the
- * `on` and `off` methods. To raise an event, the `dispatch` method shall be
- * used.
+ * Simple event bus for an application. Listeners are attached using the `on`
+ * and `off` methods. To raise an event, the `dispatch` method shall be used.
  */
 class EventBus {
   constructor({ dispatchToDOM = false } = {}) {
@@ -832,6 +831,9 @@ class EventBus {
 
 let globalEventBus = null;
 function getGlobalEventBus(dispatchToDOM = false) {
+  console.error(
+    "getGlobalEventBus is deprecated, use a manually created EventBus instance instead."
+  );
   if (!globalEventBus) {
     globalEventBus = new EventBus({ dispatchToDOM });
   }

web/viewer.js

@@ -60,7 +60,7 @@ function getViewerConfiguration() {
     appContainer: document.body,
     mainContainer: document.getElementById("viewerContainer"),
     viewerContainer: document.getElementById("viewer"),
-    eventBus: null, // Using global event bus with (optional) DOM events.
+    eventBus: null,
     toolbar: {
       container: document.getElementById("toolbarViewer"),
       numPages: document.getElementById("numPages"),