From bc2bb18af7543f2aabb5ce311ed658b1da471cc2 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 27 Aug 2021 17:45:34 +0200
Subject: [PATCH] Simplify the `PDFViewerApplication.supportsFullscreen` getter

A lot of the code in this getter has existed ever since the initial PresentationMode-implementation was first added all the way back in PR 1938 (which is nine years ago now).
At this point in time however, there's now a simpler way detect if a browser supports the FullScreen API and we should thus be able to simplify this getter; please refer to https://developer.mozilla.org/en-US/docs/Web/API/Document/fullscreenEnabled#browser_compatibility
---
 web/app.js | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/web/app.js b/web/app.js
index 5d12b6dda..c2c6b7eae 100644
--- a/web/app.js
+++ b/web/app.js
@@ -679,21 +679,13 @@ const PDFViewerApplication = {
     if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
       return shadow(this, "supportsFullscreen", document.fullscreenEnabled);
     }
-    const doc = document.documentElement;
-    let support = !!(
-      doc.requestFullscreen ||
-      doc.mozRequestFullScreen ||
-      doc.webkitRequestFullScreen
+    return shadow(
+      this,
+      "supportsFullscreen",
+      document.fullscreenEnabled ||
+        document.mozFullScreenEnabled ||
+        document.webkitFullscreenEnabled
     );
-
-    if (
-      document.fullscreenEnabled === false ||
-      document.mozFullScreenEnabled === false ||
-      document.webkitFullscreenEnabled === false
-    ) {
-      support = false;
-    }
-    return shadow(this, "supportsFullscreen", support);
   },
 
   get supportsIntegratedFind() {