Add downloader (video -> mp3) plugin (in music menu)

plugins/downloader/back.js

@@ -0,0 +1,33 @@
+const { join } = require("path");
+
+const { dialog } = require("electron");
+
+const { injectCSS, listenAction } = require("../utils");
+const { ACTIONS, CHANNEL } = require("./actions.js");
+
+const sendError = (win, err) => {
+	const dialogOpts = {
+		type: "info",
+		buttons: ["OK"],
+		title: "Error in download!",
+		message: "Argh! Apologies, download failed…",
+		detail: err.toString(),
+	};
+	dialog.showMessageBox(dialogOpts);
+};
+
+function handle(win) {
+	injectCSS(win.webContents, join(__dirname, "style.css"));
+
+	listenAction(CHANNEL, (event, action, error) => {
+		switch (action) {
+			case ACTIONS.ERROR:
+				sendError(win, error);
+				break;
+			default:
+				console.log("Unknown action: " + action);
+		}
+	});
+}
+
+module.exports = handle;