#!/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 AboutDialogExample {

    // Create the application itself

    constructor() {

        this.application = new Gtk.Application({

            application_id: 'org.example.jsaboutdialog',

            flags: Gio.ApplicationFlags.FLAGS_NONE

        });

        // Connect 'activate' and 'startup' signals to the callback functions

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

        this.application.connect('startup', this._onStartup.bind(this));

    }

    // Callback function for 'activate' signal presents windows when active

    _onActivate() {

        this._window.present();

    }

    // Callback function for 'startup' signal creates the menu and builds the UI

    _onStartup() {

        this._initMenus();

        this._buildUI();

    }

    // Build the application's UI

    _buildUI() {

        // Create the application window

        this._window = new Gtk.ApplicationWindow({ application: this.application,

                                                   window_position: Gtk.WindowPosition.CENTER,

                                                   title: "AboutDialog Example",

                                                   default_height: 250,

                                                   default_width: 350 });

        // Show the window and all child widgets

        this._window.show_all();

    }

    // Create the application menu

    _initMenus() {

        let menu = new Gio.Menu();

        menu.append("About", 'app.about');

        menu.append("Quit",'app.quit');

        this.application.set_app_menu(menu);

        // Create the "About" menu option and have it call the _showAbout() function

        let aboutAction = new Gio.SimpleAction({ name: 'about' });

        aboutAction.connect('activate', () => { this._showAbout(); });

        this.application.add_action(aboutAction);

        // Create the "Quit" menu option and have it close the window

        let quitAction = new Gio.SimpleAction ({ name: 'quit' });

        quitAction.connect('activate', () => { this._window.destroy(); });

        this.application.add_action(quitAction);

    }

    _showAbout() {

        // String arrays of the names of the people involved in the project

        var authors = ["GNOME Documentation Team"];

        var documenters = ["GNOME Documentation Team"];

        // Create the About dialog

        let aboutDialog = new Gtk.AboutDialog({ title: "AboutDialog Example",

                                                program_name: "GtkApplication Example",

                                                copyright: "Copyright \xa9 2012 GNOME Documentation Team",

                                                authors: authors,

                                                documenters: documenters,

                                                website: "http://developer.gnome.org",

                                                website_label: "GNOME Developer Website" });

        // Attach the About dialog to the window

        aboutDialog.modal = true;

        aboutDialog.transient_for = this._window;

        // Show the About dialog

        aboutDialog.show();

        // Connect the Close button to the destroy signal for the dialog

        aboutDialog.connect('response', function() {

            aboutDialog.destroy();

        });

    }

};

// Run the application

let app = new AboutDialogExample();

app.application.run(ARGV);