From cad3afadc26577ed1afeccdc3cd3812ef481201e Mon Sep 17 00:00:00 2001
From: glacambre <code@lacamb.re>
Date: Tue, 2 Oct 2018 12:38:30 +0200
Subject: [PATCH] messaging.ts: Implement messageOwnTab function

messageOwnTab does exactly what the name suggests. In a lot of cases,
it can and should replace messageActiveTab when it is called from the
content/commandline_frame script.
---
 src/messaging.ts | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/messaging.ts b/src/messaging.ts
index 75b0c8d7..1d2b3664 100644
--- a/src/messaging.ts
+++ b/src/messaging.ts
@@ -7,6 +7,7 @@ export type TabMessageType =
     | "commandline_content"
     | "commandline_frame"
 export type NonTabMessageType =
+    | "tabid_background"
     | "commandline_background"
     | "controller_background"
     | "browser_proxy_background"
@@ -83,6 +84,18 @@ export async function messageTab(tabId, type: TabMessageType, command, args?) {
     return browserBg.tabs.sendMessage(tabId, message)
 }
 
+let ownTabId = undefined
+export async function messageOwnTab(type: TabMessageType, command, args?) {
+    if (ownTabId === undefined) {
+        ownTabId = await browser.runtime.sendMessage({
+            type: "tabid_background",
+        })
+    }
+    if (ownTabId === undefined)
+        throw new Error("Can't message own tab: ownTabId is undefined")
+    return messageTab(ownTabId, type, command, args)
+}
+
 export async function messageAllTabs(
     type: TabMessageType,
     command: string,
@@ -112,6 +125,12 @@ export function addListener(type: MessageType, callback: listener) {
     }
 }
 
+addListener("tabid_background", (message, sender, sendResponse) => {
+    sendResponse(
+        sender.tab ? sender.tab.id : new Error("Message sender not in a tab"),
+    )
+})
+
 /** Recv a message from runtime.onMessage and send to all listeners */
 function onMessage(message, sender, sendResponse) {
     if (listeners.get(message.type)) {