Merge pull request #17967 from Snuffleupagus/eventBus-signal

Add `signal`-support in the `EventBus`, and utilize it in the viewer (PR 17964 follow-up)

test/unit/event_utils_spec.js

@@ -143,6 +143,60 @@ describe("event_utils", function () {
       expect(onceCount).toEqual(1);
     });
 
+    it("dispatch event to handlers with/without 'signal' option, aborted *before* dispatch", function () {
+      const eventBus = new EventBus();
+      const ac = new AbortController();
+      let multipleCount = 0,
+        noneCount = 0;
+
+      eventBus.on("test", function () {
+        multipleCount++;
+      });
+      eventBus.on(
+        "test",
+        function () {
+          noneCount++;
+        },
+        { signal: ac.signal }
+      );
+
+      ac.abort();
+
+      eventBus.dispatch("test");
+      eventBus.dispatch("test");
+      eventBus.dispatch("test");
+
+      expect(multipleCount).toEqual(3);
+      expect(noneCount).toEqual(0);
+    });
+
+    it("dispatch event to handlers with/without 'signal' option, aborted *after* dispatch", function () {
+      const eventBus = new EventBus();
+      const ac = new AbortController();
+      let multipleCount = 0,
+        onceCount = 0;
+
+      eventBus.on("test", function () {
+        multipleCount++;
+      });
+      eventBus.on(
+        "test",
+        function () {
+          onceCount++;
+        },
+        { signal: ac.signal }
+      );
+
+      eventBus.dispatch("test");
+      ac.abort();
+
+      eventBus.dispatch("test");
+      eventBus.dispatch("test");
+
+      expect(multipleCount).toEqual(3);
+      expect(onceCount).toEqual(1);
+    });
+
     it("should not re-dispatch to DOM", async function () {
       if (isNodeJS) {
         pending("Document is not supported in Node.js.");

web/annotation_layer_builder.js

@@ -50,7 +50,7 @@ import { PresentationModeState } from "./ui_utils.js";
 class AnnotationLayerBuilder {
   #onAppend = null;
 
-  #onPresentationModeChanged = null;
+  #eventAbortController = null;
 
   /**
    * @param {AnnotationLayerBuilderOptions} options
@@ -155,13 +155,15 @@ class AnnotationLayerBuilder {
     if (this.linkService.isInPresentationMode) {
       this.#updatePresentationModeState(PresentationModeState.FULLSCREEN);
     }
-    if (!this.#onPresentationModeChanged) {
-      this.#onPresentationModeChanged = evt => {
-        this.#updatePresentationModeState(evt.state);
-      };
+    if (!this.#eventAbortController) {
+      this.#eventAbortController = new AbortController();
+
       this._eventBus?._on(
         "presentationmodechanged",
-        this.#onPresentationModeChanged
+        evt => {
+          this.#updatePresentationModeState(evt.state);
+        },
+        { signal: this.#eventAbortController.signal }
       );
     }
   }
@@ -169,13 +171,8 @@ class AnnotationLayerBuilder {
   cancel() {
     this._cancelled = true;
 
-    if (this.#onPresentationModeChanged) {
-      this._eventBus?._off(
-        "presentationmodechanged",
-        this.#onPresentationModeChanged
-      );
-      this.#onPresentationModeChanged = null;
-    }
+    this.#eventAbortController?.abort();
+    this.#eventAbortController = null;
   }
 
   hide() {

web/app.js

@@ -157,7 +157,7 @@ const PDFViewerApplication = {
   url: "",
   baseUrl: "",
   _downloadUrl: "",
-  _boundEvents: Object.create(null),
+  _eventBusAbortController: null,
   _windowAbortController: null,
   documentInfo: null,
   metadata: null,
@@ -1832,75 +1832,87 @@ const PDFViewerApplication = {
   },
 
   bindEvents() {
-    const { eventBus, _boundEvents } = this;
+    if (this._eventBusAbortController) {
+      return;
+    }
+    this._eventBusAbortController = new AbortController();
 
-    _boundEvents.beforePrint = this.beforePrint.bind(this);
-    _boundEvents.afterPrint = this.afterPrint.bind(this);
+    const {
+      eventBus,
+      _eventBusAbortController: { signal },
+    } = this;
 
-    eventBus._on("resize", webViewerResize);
-    eventBus._on("hashchange", webViewerHashchange);
-    eventBus._on("beforeprint", _boundEvents.beforePrint);
-    eventBus._on("afterprint", _boundEvents.afterPrint);
-    eventBus._on("pagerender", webViewerPageRender);
-    eventBus._on("pagerendered", webViewerPageRendered);
-    eventBus._on("updateviewarea", webViewerUpdateViewarea);
-    eventBus._on("pagechanging", webViewerPageChanging);
-    eventBus._on("scalechanging", webViewerScaleChanging);
-    eventBus._on("rotationchanging", webViewerRotationChanging);
-    eventBus._on("sidebarviewchanged", webViewerSidebarViewChanged);
-    eventBus._on("pagemode", webViewerPageMode);
-    eventBus._on("namedaction", webViewerNamedAction);
-    eventBus._on("presentationmodechanged", webViewerPresentationModeChanged);
-    eventBus._on("presentationmode", webViewerPresentationMode);
+    eventBus._on("resize", webViewerResize, { signal });
+    eventBus._on("hashchange", webViewerHashchange, { signal });
+    eventBus._on("beforeprint", this.beforePrint.bind(this), { signal });
+    eventBus._on("afterprint", this.afterPrint.bind(this), { signal });
+    eventBus._on("pagerender", webViewerPageRender, { signal });
+    eventBus._on("pagerendered", webViewerPageRendered, { signal });
+    eventBus._on("updateviewarea", webViewerUpdateViewarea, { signal });
+    eventBus._on("pagechanging", webViewerPageChanging, { signal });
+    eventBus._on("scalechanging", webViewerScaleChanging, { signal });
+    eventBus._on("rotationchanging", webViewerRotationChanging, { signal });
+    eventBus._on("sidebarviewchanged", webViewerSidebarViewChanged, { signal });
+    eventBus._on("pagemode", webViewerPageMode, { signal });
+    eventBus._on("namedaction", webViewerNamedAction, { signal });
+    eventBus._on("presentationmodechanged", webViewerPresentationModeChanged, {
+      signal,
+    });
+    eventBus._on("presentationmode", webViewerPresentationMode, { signal });
     eventBus._on(
       "switchannotationeditormode",
-      webViewerSwitchAnnotationEditorMode
+      webViewerSwitchAnnotationEditorMode,
+      { signal }
     );
     eventBus._on(
       "switchannotationeditorparams",
-      webViewerSwitchAnnotationEditorParams
+      webViewerSwitchAnnotationEditorParams,
+      { signal }
     );
-    eventBus._on("print", webViewerPrint);
-    eventBus._on("download", webViewerDownload);
-    eventBus._on("firstpage", webViewerFirstPage);
-    eventBus._on("lastpage", webViewerLastPage);
-    eventBus._on("nextpage", webViewerNextPage);
-    eventBus._on("previouspage", webViewerPreviousPage);
-    eventBus._on("zoomin", webViewerZoomIn);
-    eventBus._on("zoomout", webViewerZoomOut);
-    eventBus._on("zoomreset", webViewerZoomReset);
-    eventBus._on("pagenumberchanged", webViewerPageNumberChanged);
-    eventBus._on("scalechanged", webViewerScaleChanged);
-    eventBus._on("rotatecw", webViewerRotateCw);
-    eventBus._on("rotateccw", webViewerRotateCcw);
-    eventBus._on("optionalcontentconfig", webViewerOptionalContentConfig);
-    eventBus._on("switchscrollmode", webViewerSwitchScrollMode);
-    eventBus._on("scrollmodechanged", webViewerScrollModeChanged);
-    eventBus._on("switchspreadmode", webViewerSwitchSpreadMode);
-    eventBus._on("spreadmodechanged", webViewerSpreadModeChanged);
-    eventBus._on("documentproperties", webViewerDocumentProperties);
-    eventBus._on("findfromurlhash", webViewerFindFromUrlHash);
-    eventBus._on("updatefindmatchescount", webViewerUpdateFindMatchesCount);
-    eventBus._on("updatefindcontrolstate", webViewerUpdateFindControlState);
+    eventBus._on("print", webViewerPrint, { signal });
+    eventBus._on("download", webViewerDownload, { signal });
+    eventBus._on("firstpage", webViewerFirstPage, { signal });
+    eventBus._on("lastpage", webViewerLastPage, { signal });
+    eventBus._on("nextpage", webViewerNextPage, { signal });
+    eventBus._on("previouspage", webViewerPreviousPage, { signal });
+    eventBus._on("zoomin", webViewerZoomIn, { signal });
+    eventBus._on("zoomout", webViewerZoomOut, { signal });
+    eventBus._on("zoomreset", webViewerZoomReset, { signal });
+    eventBus._on("pagenumberchanged", webViewerPageNumberChanged, { signal });
+    eventBus._on("scalechanged", webViewerScaleChanged, { signal });
+    eventBus._on("rotatecw", webViewerRotateCw, { signal });
+    eventBus._on("rotateccw", webViewerRotateCcw, { signal });
+    eventBus._on("optionalcontentconfig", webViewerOptionalContentConfig, {
+      signal,
+    });
+    eventBus._on("switchscrollmode", webViewerSwitchScrollMode, { signal });
+    eventBus._on("scrollmodechanged", webViewerScrollModeChanged, { signal });
+    eventBus._on("switchspreadmode", webViewerSwitchSpreadMode, { signal });
+    eventBus._on("spreadmodechanged", webViewerSpreadModeChanged, { signal });
+    eventBus._on("documentproperties", webViewerDocumentProperties, { signal });
+    eventBus._on("findfromurlhash", webViewerFindFromUrlHash, { signal });
+    eventBus._on("updatefindmatchescount", webViewerUpdateFindMatchesCount, {
+      signal,
+    });
+    eventBus._on("updatefindcontrolstate", webViewerUpdateFindControlState, {
+      signal,
+    });
 
     if (AppOptions.get("pdfBug")) {
-      _boundEvents.reportPageStatsPDFBug = reportPageStatsPDFBug;
-
-      eventBus._on("pagerendered", _boundEvents.reportPageStatsPDFBug);
-      eventBus._on("pagechanging", _boundEvents.reportPageStatsPDFBug);
+      eventBus._on("pagerendered", reportPageStatsPDFBug, { signal });
+      eventBus._on("pagechanging", reportPageStatsPDFBug, { signal });
     }
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
-      eventBus._on("fileinputchange", webViewerFileInputChange);
-      eventBus._on("openfile", webViewerOpenFile);
+      eventBus._on("fileinputchange", webViewerFileInputChange, { signal });
+      eventBus._on("openfile", webViewerOpenFile, { signal });
     }
     if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
-      // The `unbindEvents` method is unused in MOZCENTRAL builds,
-      // hence we don't need to unregister these event listeners.
       eventBus._on(
         "annotationeditorstateschanged",
-        webViewerAnnotationEditorStatesChanged
+        webViewerAnnotationEditorStatesChanged,
+        { signal }
       );
-      eventBus._on("reporttelemetry", webViewerReportTelemetry);
+      eventBus._on("reporttelemetry", webViewerReportTelemetry, { signal });
     }
   },
 
@@ -2049,62 +2061,8 @@ const PDFViewerApplication = {
   },
 
   unbindEvents() {
-    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
-      throw new Error("Not implemented: unbindEvents");
-    }
-    const { eventBus, _boundEvents } = this;
-
-    eventBus._off("resize", webViewerResize);
-    eventBus._off("hashchange", webViewerHashchange);
-    eventBus._off("beforeprint", _boundEvents.beforePrint);
-    eventBus._off("afterprint", _boundEvents.afterPrint);
-    eventBus._off("pagerender", webViewerPageRender);
-    eventBus._off("pagerendered", webViewerPageRendered);
-    eventBus._off("updateviewarea", webViewerUpdateViewarea);
-    eventBus._off("pagechanging", webViewerPageChanging);
-    eventBus._off("scalechanging", webViewerScaleChanging);
-    eventBus._off("rotationchanging", webViewerRotationChanging);
-    eventBus._off("sidebarviewchanged", webViewerSidebarViewChanged);
-    eventBus._off("pagemode", webViewerPageMode);
-    eventBus._off("namedaction", webViewerNamedAction);
-    eventBus._off("presentationmodechanged", webViewerPresentationModeChanged);
-    eventBus._off("presentationmode", webViewerPresentationMode);
-    eventBus._off("print", webViewerPrint);
-    eventBus._off("download", webViewerDownload);
-    eventBus._off("firstpage", webViewerFirstPage);
-    eventBus._off("lastpage", webViewerLastPage);
-    eventBus._off("nextpage", webViewerNextPage);
-    eventBus._off("previouspage", webViewerPreviousPage);
-    eventBus._off("zoomin", webViewerZoomIn);
-    eventBus._off("zoomout", webViewerZoomOut);
-    eventBus._off("zoomreset", webViewerZoomReset);
-    eventBus._off("pagenumberchanged", webViewerPageNumberChanged);
-    eventBus._off("scalechanged", webViewerScaleChanged);
-    eventBus._off("rotatecw", webViewerRotateCw);
-    eventBus._off("rotateccw", webViewerRotateCcw);
-    eventBus._off("optionalcontentconfig", webViewerOptionalContentConfig);
-    eventBus._off("switchscrollmode", webViewerSwitchScrollMode);
-    eventBus._off("scrollmodechanged", webViewerScrollModeChanged);
-    eventBus._off("switchspreadmode", webViewerSwitchSpreadMode);
-    eventBus._off("spreadmodechanged", webViewerSpreadModeChanged);
-    eventBus._off("documentproperties", webViewerDocumentProperties);
-    eventBus._off("findfromurlhash", webViewerFindFromUrlHash);
-    eventBus._off("updatefindmatchescount", webViewerUpdateFindMatchesCount);
-    eventBus._off("updatefindcontrolstate", webViewerUpdateFindControlState);
-
-    if (_boundEvents.reportPageStatsPDFBug) {
-      eventBus._off("pagerendered", _boundEvents.reportPageStatsPDFBug);
-      eventBus._off("pagechanging", _boundEvents.reportPageStatsPDFBug);
-
-      _boundEvents.reportPageStatsPDFBug = null;
-    }
-    if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
-      eventBus._off("fileinputchange", webViewerFileInputChange);
-      eventBus._off("openfile", webViewerOpenFile);
-    }
-
-    _boundEvents.beforePrint = null;
-    _boundEvents.afterPrint = null;
+    this._eventBusAbortController?.abort();
+    this._eventBusAbortController = null;
   },
 
   unbindWindowEvents() {

web/event_utils.js

@@ -44,29 +44,21 @@ async function waitOnEventOrTimeout({ target, name, delay = 0 }) {
     throw new Error("waitOnEventOrTimeout - invalid parameters.");
   }
   const { promise, resolve } = Promise.withResolvers();
+  const ac = new AbortController();
 
   function handler(type) {
-    if (target instanceof EventBus) {
-      target._off(name, eventHandler);
-    } else {
-      target.removeEventListener(name, eventHandler);
-    }
+    ac.abort(); // Remove event listener.
+    clearTimeout(timeout);
 
-    if (timeout) {
-      clearTimeout(timeout);
-    }
     resolve(type);
   }
 
-  const eventHandler = handler.bind(null, WaitOnType.EVENT);
-  if (target instanceof EventBus) {
-    target._on(name, eventHandler);
-  } else {
-    target.addEventListener(name, eventHandler);
-  }
+  const evtMethod = target instanceof EventBus ? "_on" : "addEventListener";
+  target[evtMethod](name, handler.bind(null, WaitOnType.EVENT), {
+    signal: ac.signal,
+  });
 
-  const timeoutHandler = handler.bind(null, WaitOnType.TIMEOUT);
-  const timeout = setTimeout(timeoutHandler, delay);
+  const timeout = setTimeout(handler.bind(null, WaitOnType.TIMEOUT), delay);
 
   return promise;
 }
@@ -87,6 +79,7 @@ class EventBus {
     this._on(eventName, listener, {
       external: true,
       once: options?.once,
+      signal: options?.signal,
     });
   }
 
@@ -96,10 +89,7 @@ class EventBus {
    * @param {Object} [options]
    */
   off(eventName, listener, options = null) {
-    this._off(eventName, listener, {
-      external: true,
-      once: options?.once,
-    });
+    this._off(eventName, listener);
   }
 
   /**
@@ -138,11 +128,25 @@ class EventBus {
    * @ignore
    */
   _on(eventName, listener, options = null) {
+    let rmAbort = null;
+    if (options?.signal instanceof AbortSignal) {
+      const { signal } = options;
+      if (signal.aborted) {
+        console.error("Cannot use an `aborted` signal.");
+        return;
+      }
+      const onAbort = () => this._off(eventName, listener);
+      rmAbort = () => signal.removeEventListener("abort", onAbort);
+
+      signal.addEventListener("abort", onAbort);
+    }
+
     const eventListeners = (this.#listeners[eventName] ||= []);
     eventListeners.push({
       listener,
       external: options?.external === true,
       once: options?.once === true,
+      rmAbort,
     });
   }
 
@@ -155,7 +159,9 @@ class EventBus {
       return;
     }
     for (let i = 0, ii = eventListeners.length; i < ii; i++) {
-      if (eventListeners[i].listener === listener) {
+      const evt = eventListeners[i];
+      if (evt.listener === listener) {
+        evt.rmAbort?.(); // Ensure that the `AbortSignal` listener is removed.
         eventListeners.splice(i, 1);
         return;
       }

web/pdf_history.js

@@ -53,6 +53,8 @@ function getCurrentHash() {
 }
 
 class PDFHistory {
+  #eventAbortController = null;
+
   /**
    * @param {PDFHistoryOptions} options
    */
@@ -64,7 +66,6 @@ class PDFHistory {
     this._fingerprint = "";
     this.reset();
 
-    this._boundEvents = null;
     // Ensure that we don't miss a "pagesinit" event,
     // by registering the listener immediately.
     this.eventBus._on("pagesinit", () => {
@@ -679,29 +680,22 @@ class PDFHistory {
   }
 
   #bindEvents() {
-    if (this._boundEvents) {
+    if (this.#eventAbortController) {
       return; // The event listeners were already added.
     }
-    this._boundEvents = {
-      updateViewarea: this.#updateViewarea.bind(this),
-      popState: this.#popState.bind(this),
-      pageHide: this.#pageHide.bind(this),
-    };
+    this.#eventAbortController = new AbortController();
+    const { signal } = this.#eventAbortController;
 
-    this.eventBus._on("updateviewarea", this._boundEvents.updateViewarea);
-    window.addEventListener("popstate", this._boundEvents.popState);
-    window.addEventListener("pagehide", this._boundEvents.pageHide);
+    this.eventBus._on("updateviewarea", this.#updateViewarea.bind(this), {
+      signal,
+    });
+    window.addEventListener("popstate", this.#popState.bind(this), { signal });
+    window.addEventListener("pagehide", this.#pageHide.bind(this), { signal });
   }
 
   #unbindEvents() {
-    if (!this._boundEvents) {
-      return; // The event listeners were already removed.
-    }
-    this.eventBus._off("updateviewarea", this._boundEvents.updateViewarea);
-    window.removeEventListener("popstate", this._boundEvents.popState);
-    window.removeEventListener("pagehide", this._boundEvents.pageHide);
-
-    this._boundEvents = null;
+    this.#eventAbortController?.abort();
+    this.#eventAbortController = null;
   }
 }
 

web/pdf_scripting_manager.js

@@ -37,6 +37,8 @@ class PDFScriptingManager {
 
   #docProperties = null;
 
+  #eventAbortController = null;
+
   #eventBus = null;
 
   #externalServices = null;
@@ -108,46 +110,66 @@ class PDFScriptingManager {
       await this.#destroyScripting();
       return;
     }
+    const eventBus = this.#eventBus;
 
-    this._internalEvents.set("updatefromsandbox", event => {
-      if (event?.source === window) {
-        this.#updateFromSandbox(event.detail);
-      }
-    });
-    this._internalEvents.set("dispatcheventinsandbox", event => {
-      this.#scripting?.dispatchEventInSandbox(event.detail);
-    });
+    this.#eventAbortController = new AbortController();
+    const { signal } = this.#eventAbortController;
 
-    this._internalEvents.set("pagechanging", ({ pageNumber, previous }) => {
-      if (pageNumber === previous) {
-        return; // The current page didn't change.
-      }
-      this.#dispatchPageClose(previous);
-      this.#dispatchPageOpen(pageNumber);
-    });
-    this._internalEvents.set("pagerendered", ({ pageNumber }) => {
-      if (!this._pageOpenPending.has(pageNumber)) {
-        return; // No pending "PageOpen" event for the newly rendered page.
-      }
-      if (pageNumber !== this.#pdfViewer.currentPageNumber) {
-        return; // The newly rendered page is no longer the current one.
-      }
-      this.#dispatchPageOpen(pageNumber);
-    });
-    this._internalEvents.set("pagesdestroy", async () => {
-      await this.#dispatchPageClose(this.#pdfViewer.currentPageNumber);
+    eventBus._on(
+      "updatefromsandbox",
+      event => {
+        if (event?.source === window) {
+          this.#updateFromSandbox(event.detail);
+        }
+      },
+      { signal }
+    );
+    eventBus._on(
+      "dispatcheventinsandbox",
+      event => {
+        this.#scripting?.dispatchEventInSandbox(event.detail);
+      },
+      { signal }
+    );
 
-      await this.#scripting?.dispatchEventInSandbox({
-        id: "doc",
-        name: "WillClose",
-      });
+    eventBus._on(
+      "pagechanging",
+      ({ pageNumber, previous }) => {
+        if (pageNumber === previous) {
+          return; // The current page didn't change.
+        }
+        this.#dispatchPageClose(previous);
+        this.#dispatchPageOpen(pageNumber);
+      },
+      { signal }
+    );
+    eventBus._on(
+      "pagerendered",
+      ({ pageNumber }) => {
+        if (!this._pageOpenPending.has(pageNumber)) {
+          return; // No pending "PageOpen" event for the newly rendered page.
+        }
+        if (pageNumber !== this.#pdfViewer.currentPageNumber) {
+          return; // The newly rendered page is no longer the current one.
+        }
+        this.#dispatchPageOpen(pageNumber);
+      },
+      { signal }
+    );
+    eventBus._on(
+      "pagesdestroy",
+      async () => {
+        await this.#dispatchPageClose(this.#pdfViewer.currentPageNumber);
 
-      this.#closeCapability?.resolve();
-    });
+        await this.#scripting?.dispatchEventInSandbox({
+          id: "doc",
+          name: "WillClose",
+        });
 
-    for (const [name, listener] of this._internalEvents) {
-      this.#eventBus._on(name, listener);
-    }
+        this.#closeCapability?.resolve();
+      },
+      { signal }
+    );
 
     try {
       const docProperties = await this.#docProperties(pdfDocument);
@@ -168,7 +190,7 @@ class PDFScriptingManager {
         },
       });
 
-      this.#eventBus.dispatch("sandboxcreated", { source: this });
+      eventBus.dispatch("sandboxcreated", { source: this });
     } catch (error) {
       console.error(`setDocument: "${error.message}".`);
 
@@ -242,13 +264,6 @@ class PDFScriptingManager {
     return this.#ready;
   }
 
-  /**
-   * @private
-   */
-  get _internalEvents() {
-    return shadow(this, "_internalEvents", new Map());
-  }
-
   /**
    * @private
    */
@@ -466,10 +481,8 @@ class PDFScriptingManager {
     this.#willPrintCapability?.reject(new Error("Scripting destroyed."));
     this.#willPrintCapability = null;
 
-    for (const [name, listener] of this._internalEvents) {
-      this.#eventBus._off(name, listener);
-    }
-    this._internalEvents.clear();
+    this.#eventAbortController?.abort();
+    this.#eventAbortController = null;
 
     this._pageOpenPending.clear();
     this._visitedPages.clear();

web/text_highlighter.js

@@ -29,6 +29,8 @@
  * either the text layer or XFA layer depending on the type of document.
  */
 class TextHighlighter {
+  #eventAbortController = null;
+
   /**
    * @param {TextHighlighterOptions} options
    */
@@ -37,7 +39,6 @@ class TextHighlighter {
     this.matches = [];
     this.eventBus = eventBus;
     this.pageIdx = pageIndex;
-    this._onUpdateTextLayerMatches = null;
     this.textDivs = null;
     this.textContentItemsStr = null;
     this.enabled = false;
@@ -69,15 +70,18 @@ class TextHighlighter {
       throw new Error("TextHighlighter is already enabled.");
     }
     this.enabled = true;
-    if (!this._onUpdateTextLayerMatches) {
-      this._onUpdateTextLayerMatches = evt => {
-        if (evt.pageIndex === this.pageIdx || evt.pageIndex === -1) {
-          this._updateMatches();
-        }
-      };
+
+    if (!this.#eventAbortController) {
+      this.#eventAbortController = new AbortController();
+
       this.eventBus._on(
         "updatetextlayermatches",
-        this._onUpdateTextLayerMatches
+        evt => {
+          if (evt.pageIndex === this.pageIdx || evt.pageIndex === -1) {
+            this._updateMatches();
+          }
+        },
+        { signal: this.#eventAbortController.signal }
       );
     }
     this._updateMatches();
@@ -88,13 +92,10 @@ class TextHighlighter {
       return;
     }
     this.enabled = false;
-    if (this._onUpdateTextLayerMatches) {
-      this.eventBus._off(
-        "updatetextlayermatches",
-        this._onUpdateTextLayerMatches
-      );
-      this._onUpdateTextLayerMatches = null;
-    }
+
+    this.#eventAbortController?.abort();
+    this.#eventAbortController = null;
+
     this._updateMatches(/* reset = */ true);
   }