From bb372420d7179510c5bffd0c5c7b3c7051e4014f Mon Sep 17 00:00:00 2001
From: Willian Wang <git@willian.wang>
Date: Fri, 8 Sep 2023 10:55:49 -0300
Subject: [PATCH] Replace unload event with visibilitychange (#480)

This should fix bfcache compatibility issues.

https://developer.mozilla.org/en-US/docs/Web/API/Window/unload_event#usage_notes
---
 src/content/index.js | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/content/index.js b/src/content/index.js
index 6af79f0..be529b6 100644
--- a/src/content/index.js
+++ b/src/content/index.js
@@ -9,7 +9,7 @@ const init = async () => {
   await initSettings();
   document.addEventListener("mouseup", handleMouseUp);
   document.addEventListener("keydown", handleKeyDown);
-  window.addEventListener("unload", onUnload, { once: true });
+  document.addEventListener("visibilitychange", handleVisibilityChange);
   browser.storage.onChanged.addListener(handleSettingsChange);
   browser.runtime.onMessage.addListener(handleMessage);
   overWriteLogLevel();
@@ -133,8 +133,12 @@ const handleKeyDown = e => {
   }
 };
 
-const onUnload = () => {
-  browser.storage.onChanged.removeListener(handleSettingsChange);
+const handleVisibilityChange = () => {
+  if (document.visibilityState === "hidden") {
+    browser.storage.onChanged.removeListener(handleSettingsChange);
+  } else {
+    browser.storage.onChanged.addListener(handleSettingsChange);
+  }
 };
 
 let isEnabled = true;