<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its" xmlns:xi="http://www.w3.org/2001/XInclude" type="guide" style="task" id="spinner.js" xml:lang="gl">
  <info>
  <title type="text">Spinner (JavaScript)</title>
    <link type="guide" xref="beginner.js#display-widgets"/>
    <revision version="0.1" date="2012-06-03" status="draft"/>

    <credit type="author copyright">
      <name>Taryn Fox</name>
      <email its:translate="no">jewelfox@fursona.net</email>
      <years>2012</years>
    </credit>

    <desc>Unha animación spinner</desc>
  
    <mal:credit xmlns:mal="http://projectmallard.org/1.0/" type="translator copyright">
      <mal:name>Fran Dieguez</mal:name>
      <mal:email>frandieguez@gnome.org</mal:email>
      <mal:years>2012-2013.</mal:years>
    </mal:credit>
  </info>

  <title>Indicador de progreso</title>
  <media type="image" mime="image/png" src="media/spinner.png"/>
  <p>This Spinner is stopped and started by pressing the spacebar.</p>

<code mime="application/javascript" style="numbered">#!/usr/bin/gjs

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

const Gio = imports.gi.Gio;
const GLib = imports.gi.GLib;
const Gtk = imports.gi.Gtk;
const Gdk = imports.gi.Gdk;

class SpinnerExample {

    // Create the application itself
    constructor() {
        this.application = new Gtk.Application({
            application_id: 'org.example.jsspinner',
            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 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: "Spinner Example",
            default_height: 200,
            default_width: 200,
            border_width: 30
        });

        // Create a spinner which starts spinning automatically
        this._spinner = new Gtk.Spinner ({active: true});
        this._window.add (this._spinner);

        // Connect a keypress event to the function that makes it start or stop spinning
        this._window.connect("key-press-event", this._onKeyPress.bind(this));

        // Show the window and all child widgets
        this._window.show_all();
    }

    _onKeyPress(widget, event) {

        // Get the value of the key that was pressed
        let [, keyval] = event.get_keyval();

        // If it was the spacebar, toggle the spinner to start or stop
        if (keyval == Gdk.KEY_space) {
            if (this._spinner.active == true)
                this._spinner.stop();
            else
                this._spinner.start();
        }
    }
};

// Run the application
let app = new SpinnerExample ();
app.application.run (ARGV);
</code>
<p>Neste exemplo empregaremos o seguinte:</p>
<list>
  <item><p><link href="http://www.roojs.org/seed/gir-1.2-gtk-3.0/gjs/Gdk.html">Gdk - Key Values</link></p></item>
  <item><p><link href="http://www.roojs.com/seed/gir-1.2-gtk-3.0/gjs/Gtk.Application.html">Gtk.Application</link></p></item>
  <item><p><link href="http://developer.gnome.org/gtk3/stable/GtkApplicationWindow.html">Gtk.ApplicationWindow</link></p></item>
    <item><p><link href="http://www.roojs.org/seed/gir-1.2-gtk-3.0/gjs/Gtk.Spinner.html">Gtk.Spinner</link></p></item>
</list>
</page>
