facilitate broadcasting messages to different execution contexts within the webextension

2 files changed, 116 insertions, 1 deletions

diff --git a/common/broadcast.js b/common/broadcast.js
new file mode 100644
index 0000000..bc18103
--- /dev/null
+++ b/common/broadcast.js
@@ -0,0 +1,113 @@
+/**
+ * This file is part of Haketilo.
+ *
+ * Function: Broadcast messages to different execution contexts of the extension
+ *
+ * Copyright (C) 2021 Wojtek Kosior
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you
+ * may distribute forms of that code without the copy of the GNU
+ * GPL normally required by section 4, provided you include this
+ * license notice and, in case of non-source distribution, a URL
+ * through which recipients can access the Corresponding Source.
+ * If you modify file(s) with this exception, you may extend this
+ * exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * As a special exception to the GPL, any HTML file which merely
+ * makes function calls to this code, and for that purpose
+ * includes it by reference shall be deemed a separate work for
+ * copyright law purposes. If you modify this code, you may extend
+ * this exception to your version of the code, but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * I, Wojtek Kosior, thereby promise not to sue for violation of this file's
+ * license. Although I request that you do not make use this code in a
+ * proprietary program, I am not going to enforce this in court.
+ */
+
+/*
+ * IMPORTS_START
+ * IMPORT CONNECTION_TYPE
+ * IMPORTS_END
+ */
+
+function sender_connection()
+{
+    return {
+	port: browser.runtime.connect({name: CONNECTION_TYPE.BROADCAST_SEND})
+    };
+}
+
+function out(sender_conn, channel_name, value)
+{
+    sender_conn.port.postMessage(["broadcast", channel_name, value]);
+}
+
+function prepare(sender_conn, channel_name, value, timeout=5000)
+{
+    sender_conn.port.postMessage(["prepare", channel_name, value, timeout]);
+}
+
+function discard(sender_conn)
+{
+    sender_conn.port.postMessage(["discard"]);
+}
+
+function flush(sender_conn)
+{
+    sender_conn.port.postMessage(["flush"]);
+}
+
+function listener_connection(cb)
+{
+    const conn = {
+	port: browser.runtime.connect({name: CONNECTION_TYPE.BROADCAST_LISTEN})
+    };
+
+    conn.port.onMessage.addListener(cb);
+
+    return conn;
+}
+
+function subscribe(listener_conn, channel_name)
+{
+    listener_conn.port.postMessage(["subscribe", channel_name]);
+}
+
+function unsubscribe(listener_conn, channel_name)
+{
+    listener_conn.port.postMessage(["unsubscribe", channel_name]);
+}
+
+function close(conn)
+{
+    conn.port.disconnect();
+}
+
+const broadcast = {
+    sender_connection, out, prepare, discard, flush,
+    listener_connection, subscribe, unsubscribe,
+    close
+};
+
+/*
+ * EXPORTS_START
+ * EXPORT broadcast
+ * EXPORTS_END
+ */
diff --git a/common/connection_types.js b/common/connection_types.js
index a571cb9..9747e5c 100644
--- a/common/connection_types.js
+++ b/common/connection_types.js
@@ -49,7 +49,9 @@
 const CONNECTION_TYPE = {
     REMOTE_STORAGE : "0",
     PAGE_ACTIONS : "1",
-    ACTIVITY_INFO : "2"
+    ACTIVITY_INFO : "2",
+    BROADCAST_SEND: "3",
+    BROADCAST_LISTEN: "4"
 };
 
 /*