#!/usr/bin/gjs

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

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

const Gdk = imports.gi.Gdk;

const GObject = imports.gi.GObject;

const Gtk = imports.gi.Gtk;

class ColorbuttonExample {

    // Create the application itself

    constructor() {

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

        // 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: "ColorButton",

                                                   default_width: 150,

                                                   default_height: 50,

                                                   border_width: 10 });

        this.button = new Gtk.ColorButton();

        this.color = new Gdk.RGBA();

        this.color.red = 0.0;

        this.color.green = 0.0;

        this.color.blue = 1.0;

        this.color.alpha = 0.5;

        this.button.set_rgba(this.color);

        this.button.connect("color-set", this.onColorChosen.bind(this));

        this.label = new Gtk.Label();

        this.label.set_text("Click to choose a color");

        let grid = new Gtk.Grid();

        grid.attach(this.button, 0, 0, 2, 1);

        grid.attach(this.label, 0, 1, 2, 1);

        this.window.add(grid);

        this.window.show_all();

    }

    onColorChosen() {

        let colorName = this.color.to_string();

        this.label.set_text("You chose the color " + colorName);

    }

};

// Run the application

let app = new ColorbuttonExample ();

app.application.run (ARGV);