From 9fa20ad8c5cede72655b32b3a31e6aa2cbc28374 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Tue, 9 Feb 2021 12:01:07 +0100
Subject: [PATCH] [GENERIC viewer] Skip the `iframe`-case when checking if the
 `container` div, on `BaseViewer`-instances, is absolutely positioned (PR
 12354 follow-up)

Given that `getComputedStyle` only works on visible elements, the result of PR 12354 is that if the viewer is placed in a *hidden* `iframe` the viewer will now be broken. This obviously wasn't the intention of that PR, hence I believe that we should limit the `position: absolute;` check slightly to avoid this.
---
 web/base_viewer.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/web/base_viewer.js b/web/base_viewer.js
index 0ad5257b2..3c6f169f5 100644
--- a/web/base_viewer.js
+++ b/web/base_viewer.js
@@ -172,7 +172,10 @@ class BaseViewer {
         throw new Error("Invalid `container` and/or `viewer` option.");
       }
 
-      if (getComputedStyle(this.container).position !== "absolute") {
+      if (
+        this.container.offsetParent &&
+        getComputedStyle(this.container).position !== "absolute"
+      ) {
         throw new Error("The `container` must be absolutely positioned.");
       }
     }