<?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="aboutdialog.py" xml:lang="ca">
  <info>
    <title type="text">AboutDialog (Python)</title>
    <link type="guide" xref="beginner.py#windows"/>
    <link type="next" xref="messagedialog.py"/>
    <revision version="0.1" date="2012-06-11" status="draft"/>

    <credit type="author copyright">
      <name>Marta Maria Casetti</name>
      <email its:translate="no">mmcasetti@gmail.com</email>
      <years>2012</years>
    </credit>

    <desc>A window that displays information about an application</desc>
  </info>

  <title>AboutDialog</title>
  <media type="image" mime="image/png" src="media/aboutdialog_GMenu.png"/>
  <p>An AboutDialog example using Gtk.ApplicationWindow and Menu (the "about" is displayed if "About" in the menu is selected).</p>

  <links type="section"/>

  <section id="code">
  <title>Code used to generate this example</title>

  <code mime="text/x-python" style="numbered">from gi.repository import Gtk
from gi.repository import Gio
import sys


class MyWindow(Gtk.ApplicationWindow):

     # constructor for a window (the parent window)
    def __init__(self, app):
        Gtk.Window.__init__(self, title="AboutDialog Example", application=app)
        self.set_default_size(200, 200)

        # create the about_action (a Gio.SimpleAction)
        about_action = Gio.SimpleAction.new("about", None)
        # connect the signal from the action to the function about_cb()
        about_action.connect("activate", self.about_cb)
        # add the action to the application
        app.add_action(about_action)

    # callback function for the about_action's "activate" signal
    def about_cb(self, action, parameter):
        # a  Gtk.AboutDialog
        aboutdialog = Gtk.AboutDialog()

        # lists of authors and documenters (will be used later)
        authors = ["GNOME Documentation Team"]
        documenters = ["GNOME Documentation Team"]

        # we fill in the aboutdialog
        aboutdialog.set_program_name("AboutDialog Example")
        aboutdialog.set_copyright(
            "Copyright \xc2\xa9 2012 GNOME Documentation Team")
        aboutdialog.set_authors(authors)
        aboutdialog.set_documenters(documenters)
        aboutdialog.set_website("http://developer.gnome.org")
        aboutdialog.set_website_label("GNOME Developer Website")

        # we do not want to show the title, which by default would be "About AboutDialog Example"
        # we have to reset the title of the messagedialog window after setting
        # the program name
        aboutdialog.set_title("")

        # to close the aboutdialog when "close" is clicked we connect the
        # "response" signal to on_close
        aboutdialog.connect("response", self.on_close)
        # show the aboutdialog
        aboutdialog.show()

    # destroy the aboutdialog
    def on_close(self, action, parameter):
        action.destroy()


class MyApplication(Gtk.Application):

    def __init__(self):
        Gtk.Application.__init__(self)

    def do_activate(self):
        win = MyWindow(self)
        win.show_all()

    def quit_cb(self, action, parameter):
        self.quit()

    def do_startup(self):
        Gtk.Application.do_startup(self)

        # create a menu (a Gio.Menu)
        menu = Gio.Menu()
        # append a menu item with label "About" and action "app.about"
        menu.append("About", "app.about")
        # append a menu item with label "Quit" and action "app.quit"
        menu.append("Quit", "app.quit")
        # set menu as the menu for the application
        self.set_app_menu(menu)

        # a new simpleaction - for the application
        quit_action = Gio.SimpleAction.new("quit", None)
        quit_action.connect("activate", self.quit_cb)
        self.add_action(quit_action)

app = MyApplication()
exit_status = app.run(sys.argv)
sys.exit(exit_status)
</code>

  </section>

  <section id="methods">
  <title>Useful methods for an AboutDialog widget</title>
    <p>In line 15 the signal <code>"activate"</code> is connected to the callback function <code>about_cb()</code> using <code><var>widget</var>.connect(<var>signal</var>, <var>callback function</var>)</code>. See <link xref="signals-callbacks.py"/> for a more detailed explanation.</p>
  </section>

  <section id="references">
  <title>API References</title>
  <p>
    In this sample we used the following:
  </p>
  <list>
    <item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkAboutDialog.html">GtkAboutDialog</link></p></item>
    <item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkApplicationWindow.html">GtkApplicationWindow</link></p></item>
    <item><p><link href="http://developer.gnome.org/gio/stable/GMenu.html">GMenu</link></p></item>
    <item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkApplication.html">GtkApplication</link></p></item>
  </list>
  </section>
</page>
