#!/usr/bin/gjs

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

const Gio = imports.gi.Gio;

const Gtk = imports.gi.Gtk;

class CheckButtonExample {

    // Create the application itself

    constructor() {

        this.application = new Gtk.Application({

            application_id: 'org.example.jscheckbutton',

            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 window when active

    _onActivate() {

        this._window.present();

    }

    // Callback function for 'startup' signal builds the UI

    _onStartup() {

        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,

            default_height: 100,

            default_width: 300,

            border_width: 10,

            title: "CheckButton Example"});

        // Create the check button

        this._button = new Gtk.CheckButton ({label: "Show Title"});

        this._window.add (this._button);

        // Have the check button be checked by default

        this._button.set_active (true);

        // Connect the button to a function that does something when it's toggled

        this._button.connect ("toggled", this._toggledCB.bind(this));

        // Show the window and all child widgets

        this._window.show_all();

    }

    _toggledCB() {

        // Make the window title appear or disappear when the checkbox is toggled

        if (this._button.get_active() == true)

            this._window.set_title ("CheckButton Example");

        else

            this._window.set_title ("");

    }

};

// Run the application

let app = new CheckButtonExample ();

app.application.run (ARGV);