#!/usr/bin/gjs

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

const Gio = imports.gi.Gio;

const Gtk = imports.gi.Gtk;

class SpinButtonExample {

    // Create the application itself

    constructor() {

        this.application = new Gtk.Application({

            application_id: 'org.example.jsspinbutton'

        });

        // 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,

            border_width: 20,

            title: "Kitten Feeder"});

        // Create the first spinbutton using a function

        this._kittens = Gtk.SpinButton.new_with_range (1, 9001, 1);

        this._kittens.connect ("value-changed", this._newValue.bind(this));

        // Create an adjustment to use for the second spinbutton

        this._adjustment = new Gtk.Adjustment ({

            value: 1,

            lower: 0,

            upper: 9001,

            step_increment: 1,

            page_increment: 10 });

        // Create the second spinbutton

        this._tuna = new Gtk.SpinButton ({ adjustment: this._adjustment });

        this._tuna.connect ("value-changed", this._newValue.bind(this));

        // this._tuna.set_digits (1);

        // this._tuna.set_wrap (true);

        // Create the text labels to go with the spinbuttons

        this._startLabel = new Gtk.Label ({ label: "There are " });

        this._kittenLabel = new Gtk.Label ({ label: " kitten(s), and "});

        this._tunaLabel = new Gtk.Label ({ label: " can(s) of tuna."});

        this.perKitten = Math.floor((this._tuna.get_value() / this._kittens.get_value()));

        this._lastLabel = new Gtk.Label ({

            label: "That's " + this.perKitten + " can(s) of tuna per kitten." });

        // Create a grid to put the spinbuttons and their labels in

        this._spinGrid = new Gtk.Grid ({

            halign: Gtk.Align.CENTER,

            valign: Gtk.Align.CENTER,

            margin_bottom: 20 });

        // Attach everything to the grid

        this._spinGrid.attach (this._startLabel, 0, 0, 1, 1);

        this._spinGrid.attach (this._kittens, 1, 0, 1, 1);

        this._spinGrid.attach (this._kittenLabel, 2, 0, 1, 1);

        this._spinGrid.attach (this._tuna, 3, 0, 1, 1);

        this._spinGrid.attach (this._tunaLabel, 4, 0, 1, 1);

        // Create a main grid to hold it and the last label

        this._mainGrid = new Gtk.Grid ({

            halign: Gtk.Align.CENTER,

            valign: Gtk.Align.CENTER });

        // Attach the smaller grid and the last label to the main grid

        this._mainGrid.attach (this._spinGrid, 0, 0, 1, 1);

        this._mainGrid.attach (this._lastLabel, 0, 1, 1, 1);

        // Add the main grid to the window

        this._window.add (this._mainGrid);

        // Show the window and all child widgets

        this._window.show_all();

    }

    _newValue() {

        // Update the label which shows how many cans there are per kitten

        this.perKitten = Math.floor((this._tuna.get_value() / this._kittens.get_value()))

        this._lastLabel.set_label ("That's " + this.perKitten + " can(s) of tuna per kitten.");

    }

};

// Run the application

let app = new SpinButtonExample ();

app.application.run (ARGV);