From b04bb1bfeb419604de9a87151a8baae405580449 Mon Sep 17 00:00:00 2001
From: Carlos Quintana <carlos.quintana@proton.ch>
Date: Thu, 19 May 2022 11:52:31 +0200
Subject: [PATCH] Allow to query if extension is installed

---
 src/background/index.js           | 16 ++++++++++++++++
 src/content_script/input_tools.js | 12 +++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/background/index.js b/src/background/index.js
index bfecca1..9b485d2 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -88,6 +88,20 @@ const isMessageAllowed = (url) => {
   return false;
 };
 
+/**
+ * Handle the event of a page querying if the SL extension is installed
+ * @return {{data: {version: string}, tag: string}}
+ */
+const handleExtensionInstalledQuery = () => {
+  const manifest = browser.runtime.getManifest();
+  return {
+    tag: "EXTENSION_INSTALLED_RESPONSE",
+    data: {
+      version: manifest.version,
+    },
+  };
+};
+
 /**
  * Register onMessage listener
  */
@@ -104,6 +118,8 @@ browser.runtime.onMessage.addListener(async function (request, sender) {
 
   if (request.tag === "EXTENSION_SETUP") {
     return await handleExtensionSetup();
+  } else if (request.tag === "EXTENSION_INSTALLED_QUERY") {
+    return handleExtensionInstalledQuery();
   }
 });
 
diff --git a/src/content_script/input_tools.js b/src/content_script/input_tools.js
index 424c988..85f4265 100644
--- a/src/content_script/input_tools.js
+++ b/src/content_script/input_tools.js
@@ -245,6 +245,8 @@ if (!window._hasExecutedSlExtension) {
     if (!window.hasSlListenerRegistered) {
       window.hasSlListenerRegistered = true;
 
+      let hasProcessedSetup = false;
+
       /**
        * Callback called for every event
        * @param {MessageEvent<any>} event
@@ -253,7 +255,15 @@ if (!window._hasExecutedSlExtension) {
         if (event.source !== window) return;
         if (!event.data.tag) return;
         if (event.data.tag === "PERFORM_EXTENSION_SETUP") {
-          await sendMessageToBackground("EXTENSION_SETUP");
+          if (!hasProcessedSetup) {
+            hasProcessedSetup = true;
+            await sendMessageToBackground("EXTENSION_SETUP");
+          }
+        } else if (event.data.tag === "EXTENSION_INSTALLED_QUERY") {
+          const res = await sendMessageToBackground(
+            "EXTENSION_INSTALLED_QUERY"
+          );
+          window.postMessage(res);
         }
       };