//!/usr/bin/gjs

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

const Gtk = imports.gi.Gtk;

class FontChooserWidgetExample {

    // Create the application itthis

    constructor() {

        this.application = new Gtk.Application({ application_id: 'org.example.fontchooserwidget' });

        // 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 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,

                                                    title: "FontChooserWidget",

                                                    default_width: 200,

                                                    default_height: 200,

                                                    border_width: 10 });

        this.fontChooser = new Gtk.FontChooserWidget();

        // a default font

        this.fontChooser.set_font("Sans");

        // a text to preview the font

        this.fontChooser.set_preview_text("This is an example of preview text!");

        // connect signal from the font chooser to the callback function

        this.fontChooser.connect("notify::font", this._fontCb.bind(this));

        // add the font chooser to the window

        this.window.add(this.fontChooser);

        this.window.show_all();

   }

     // callback function:

     _fontCb() {

        // print in the terminal

        print("You chose the font " + this.fontChooser.get_font());

    }

};

// Run the application

let app = new FontChooserWidgetExample();

app.application.run (ARGV);