From 547556b5b2940fb26c8d3faed131d1a2005abab2 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sun, 30 Oct 2022 17:36:20 +0100
Subject: [PATCH] Prevent keyboard interaction with form elements in
 PresentationMode (issue 12232)

This uses the relatively new `HTMLElement.inert` property, see https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/inert for additional information. The only "problem" is that this isn't yet available in all Firefox channels, but until https://bugzilla.mozilla.org/show_bug.cgi?id=1764263 is fixed we're no worse off than before.
---
 web/annotation_layer_builder.js | 50 +++++++++++++++++++++++++++++++++
 web/interfaces.js               |  5 ++++
 web/pdf_link_service.js         | 14 +++++++++
 3 files changed, 69 insertions(+)

diff --git a/web/annotation_layer_builder.js b/web/annotation_layer_builder.js
index 25dd70021..efbf308bf 100644
--- a/web/annotation_layer_builder.js
+++ b/web/annotation_layer_builder.js
@@ -24,6 +24,7 @@
 
 import { AnnotationLayer } from "pdfjs-lib";
 import { NullL10n } from "./l10n_utils.js";
+import { PresentationModeState } from "./ui_utils.js";
 
 /**
  * @typedef {Object} AnnotationLayerBuilderOptions
@@ -46,6 +47,8 @@ import { NullL10n } from "./l10n_utils.js";
  */
 
 class AnnotationLayerBuilder {
+  #onPresentationModeChanged = null;
+
   /**
    * @param {AnnotationLayerBuilderOptions} options
    */
@@ -82,6 +85,7 @@ class AnnotationLayerBuilder {
 
     this.div = null;
     this._cancelled = false;
+    this._eventBus = linkService.eventBus;
   }
 
   /**
@@ -134,11 +138,34 @@ class AnnotationLayerBuilder {
 
       AnnotationLayer.render(parameters);
       this.l10n.translate(this.div);
+
+      // Ensure that interactive form elements in the annotationLayer are
+      // disabled while PresentationMode is active (see issue 12232).
+      if (this.linkService.isInPresentationMode) {
+        this.#updatePresentationModeState(PresentationModeState.FULLSCREEN);
+      }
+      if (!this.#onPresentationModeChanged) {
+        this.#onPresentationModeChanged = evt => {
+          this.#updatePresentationModeState(evt.state);
+        };
+        this._eventBus?._on(
+          "presentationmodechanged",
+          this.#onPresentationModeChanged
+        );
+      }
     }
   }
 
   cancel() {
     this._cancelled = true;
+
+    if (this.#onPresentationModeChanged) {
+      this._eventBus?._off(
+        "presentationmodechanged",
+        this.#onPresentationModeChanged
+      );
+      this.#onPresentationModeChanged = null;
+    }
   }
 
   hide() {
@@ -147,6 +174,29 @@ class AnnotationLayerBuilder {
     }
     this.div.hidden = true;
   }
+
+  #updatePresentationModeState(state) {
+    if (!this.div) {
+      return;
+    }
+    let disableFormElements = false;
+
+    switch (state) {
+      case PresentationModeState.FULLSCREEN:
+        disableFormElements = true;
+        break;
+      case PresentationModeState.NORMAL:
+        break;
+      default:
+        return;
+    }
+    for (const section of this.div.childNodes) {
+      if (section.hasAttribute("data-internal-link")) {
+        continue;
+      }
+      section.inert = disableFormElements;
+    }
+  }
 }
 
 export { AnnotationLayerBuilder };
diff --git a/web/interfaces.js b/web/interfaces.js
index 7cce362fc..2331511a1 100644
--- a/web/interfaces.js
+++ b/web/interfaces.js
@@ -61,6 +61,11 @@ class IPDFLinkService {
    */
   set rotation(value) {}
 
+  /**
+   * @type {boolean}
+   */
+  get isInPresentationMode() {}
+
   /**
    * @type {boolean}
    */
diff --git a/web/pdf_link_service.js b/web/pdf_link_service.js
index 52cba0ec2..de8172e6b 100644
--- a/web/pdf_link_service.js
+++ b/web/pdf_link_service.js
@@ -173,6 +173,13 @@ class PDFLinkService {
     this.pdfViewer.pagesRotation = value;
   }
 
+  /**
+   * @type {boolean}
+   */
+  get isInPresentationMode() {
+    return this.pdfViewer.isInPresentationMode;
+  }
+
   #goToDestinationHelper(rawDest, namedDest = null, explicitDest) {
     // Dest array looks like that: <page-ref> </XYZ|/FitXXX> <args..>
     const destRef = explicitDest[0];
@@ -673,6 +680,13 @@ class SimpleLinkService {
    */
   set rotation(value) {}
 
+  /**
+   * @type {boolean}
+   */
+  get isInPresentationMode() {
+    return false;
+  }
+
   /**
    * @param {string|Array} dest - The named, or explicit, PDF destination.
    */