#!/usr/bin/gjs

imports.gi.versions.Gtk = '3.0';

const Gio = imports.gi.Gio;

const GLib = imports.gi.GLib;

const Gtk = imports.gi.Gtk;

class Application {

    //create the application

    constructor() {

        this.application = new Gtk.Application({

            application_id: 'org.example.myapp',

            flags: Gio.ApplicationFlags.FLAGS_NONE

        });

       this.application.connect('activate', this._onActivate.bind(this));

    }

    //callback function for 'activate' signal

    _onActivate() {

        let myWindow = new Gtk.Window({type: Gtk.WindowType.TOPLEVEL});

        myWindow.title = "Welcome to GNOME";

       /* Here are a few ways we can customize our window.

       Try uncommenting them or changing their values! */

        //myWindow.set_default_size (400,200);

        //myWindow.set_has_resize_grip (false);

        //myWindow.set_opacity (0.5);

        //myWindow.maximize ();

        //show the window and all child widgets (none in this case)

        myWindow.show_all();

        this.application.add_window(myWindow);

    }

};

//run the application

let app = new Application ();

app.application.run (ARGV);