From 5a069464692236d34016ce35e060afaaeacd44a0 Mon Sep 17 00:00:00 2001
From: JeLuF <jf@mormo.org>
Date: Thu, 10 Nov 2022 23:23:20 +0100
Subject: [PATCH] Add event listener beforeunload When closing the window, a
 warning is shown if there are any render results.

---
 ui/media/js/main.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/ui/media/js/main.js b/ui/media/js/main.js
index abed8b7c..9dc83eeb 100644
--- a/ui/media/js/main.js
+++ b/ui/media/js/main.js
@@ -1417,4 +1417,17 @@ document.querySelectorAll(".tab").forEach(tab => {
     })
 })
 
+window.addEventListener("beforeunload", function(e) {
+    const msg = "Unsaved pictures will be lost!";
+
+    let elementList = document.getElementsByClassName("imageTaskContainer");
+    if (elementList.length != 0) {
+        e.preventDefault();
+        (e || window.event).returnValue = msg;
+        return msg;
+    } else {
+        return true;
+    }
+});
+
 createCollapsibles()