<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="menubar.c" xml:lang="gl">

  <info>

    <title type="text">MenuBar (C)</title>

    <link type="guide" xref="c#menu-combo-toolbar"/>

    <link type="seealso" xref="aboutdialog.c"/>

    <link type="seealso" xref="gmenu.c"/>

    <revision version="0.2" date="2012-08-19" status="draft"/>

    <credit type="author copyright">

      <name>Monica Kochofar</name>

      <email its:translate="no">monicakochofar@gmail.com</email>

      <years>2012</years>

    </credit>

    <desc>A widget which holds GtkMenuItem widgets</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>MenuBar</title>

  <media type="image" mime="image/png" src="media/menubar.png"/>

  
A MenuBar created using XML and GtkBuilder.

<note>

    For a more in-depth look at this sample, please do not hesitate to check out the <link xref="menubar.vala">Vala MenuBar</link> and/or

<link xref="menubar.py">Python MenuBar</link> tutorials.

  
</note>

#include <gtk/gtk.h>

/* Callback function for the "copy" action */

static void

copy_callback (GSimpleAction *simple,

            GVariant      *parameter,

            gpointer       user_data)

{

   g_print ("\"Copy\" activated\n");

}

/* Callback function for the "paste" action */

static void

paste_callback (GSimpleAction *simple,

            GVariant      *parameter,

            gpointer       user_data)

{

   g_print ("\"Paste\" activated\n");

}

/* Callback function for the "shape" action */

static void

shape_callback (GSimpleAction *simple,

            GVariant      *parameter,

            gpointer       user_data)

{

   /* We first gather the value of the GVariant instance with a string type.

    * The overall goal here is to see if shape is set to line, triangle, etc,

    * and put that value within the variable "answer".

    */

   const gchar *answer = g_variant_get_string (parameter, NULL);

   g_printf ("Shape is set to %s.\n", answer);

   /* Note that we set the state of the action */

   g_simple_action_set_state (simple, parameter);

}

/* Callback function in which closes the about_dialog created below */

static void

on_close (GtkDialog *dialog,

          gint       response_id,

          gpointer   user_data)

{

  gtk_widget_destroy (GTK_WIDGET (dialog));

}

/* Callback function for the about action (see aboutdialog.c example) */

static void

about_callback (GSimpleAction *simple,

            GVariant      *parameter,

            gpointer       user_data)

{

   GtkWidget *about_dialog;

   about_dialog = gtk_about_dialog_new ();

   const gchar *authors[] = {"GNOME Documentation Team", NULL};

   const gchar *documenters[] = {"GNOME Documentation Team", NULL};

   /* Fill in the about_dialog with the desired information */

   gtk_about_dialog_set_program_name (GTK_ABOUT_DIALOG (about_dialog), "AboutDialog Example");

   gtk_about_dialog_set_copyright (GTK_ABOUT_DIALOG (about_dialog), "Copyright \xc2\xa9 2012 GNOME Documentation Team");

   gtk_about_dialog_set_authors (GTK_ABOUT_DIALOG (about_dialog), authors);

   gtk_about_dialog_set_documenters (GTK_ABOUT_DIALOG (about_dialog), documenters);

   gtk_about_dialog_set_website_label (GTK_ABOUT_DIALOG (about_dialog), "GNOME Developer Website");

   gtk_about_dialog_set_website (GTK_ABOUT_DIALOG (about_dialog), "http://developer.gnome.org");

   /* The "response" signal is emitted when the dialog receives a delete event,

    * therefore we connect that signal to the on_close callback function

    * created above.

    */

   g_signal_connect (GTK_DIALOG (about_dialog), "response",

                    G_CALLBACK (on_close), NULL);

   /* Show the about dialog */

   gtk_widget_show (about_dialog);

}

static void

activate (GtkApplication *app,

          gpointer        user_data)

{

  GtkWidget *window;

  GSimpleAction *copy_action;

  GSimpleAction *paste_action;

  GSimpleAction *shape_action;

  GSimpleAction *about_action;

  /* Create a window with a title and a default size */

  window = gtk_application_window_new (app);

  gtk_window_set_title (GTK_WINDOW (window), "MenuBar Example");

  gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);

  /* Begin creating the "copy" action.

   * Note that it is an action without a state.

   */

  copy_action = g_simple_action_new ("copy", NULL);

  /* Connected to a callback function */

  g_signal_connect (copy_action, "activate", G_CALLBACK (copy_callback),

                    GTK_WINDOW (window));

  /* Added to the window */

  g_action_map_add_action (G_ACTION_MAP (window), G_ACTION (copy_action));

  /* Begin creating the "paste" action.

   * Note that it is an action without a state.

   */

  paste_action = g_simple_action_new ("paste", NULL);

  /* Connect the action to a callback function */

  g_signal_connect (paste_action, "activate", G_CALLBACK (paste_callback),

                    GTK_WINDOW (window));

  /* Add it to the window */

  g_action_map_add_action (G_ACTION_MAP (window), G_ACTION (paste_action));

  /* Begin creating the "shape" action.

   * Note that it is an action with a state.

   * First we state that the parameter type of the simple action is a string.

   * When using g_variant_type_new, it is appropriate to free the return value

   * once you're done with it.

   */

  GVariantType *type_string = g_variant_type_new ("s");

  /* parameters for the g_simple_action_new_stateful are: (name, parameter type,

   * initial state).

   */

  shape_action = g_simple_action_new_stateful ("shape", type_string,

                                               g_variant_new_string ("line"));

  /* Connect the action to a callback function */

  g_signal_connect (shape_action, "activate", G_CALLBACK (shape_callback),

                    GTK_WINDOW (window));

  /* Add it to the window */

  g_action_map_add_action (G_ACTION_MAP (window), G_ACTION (shape_action));

  g_variant_type_free (type_string);

  /* Begin creating the "about" action.

   * Note that it is an action without a state.

   */

  about_action = g_simple_action_new ("about", NULL);

  /* Connect the action to a callback function */

  g_signal_connect (about_action, "activate", G_CALLBACK (about_callback),

                    GTK_WINDOW (window));

  /* Add it to the window */

  g_action_map_add_action (G_ACTION_MAP (window), G_ACTION (about_action));

  gtk_widget_show_all (window);

}

/* Callback function for the "new" action */

static void

new_callback (GSimpleAction *simple,

         GVariant      *parameter,

         gpointer       user_data)

{

  g_print ("You clicked \"New\"\n");

}

/* Callback function for the "quit" action */

static void

quit_callback (GSimpleAction *simple,

         GVariant      *parameter,

         gpointer       user_data)

{

  GApplication *application = user_data;

  g_print ("You clicked \"Quit\"\n");

  g_application_quit (application);

}

/* Callback function for the "state" action */

static void

state_callback (GSimpleAction *simple,

         GVariant      *parameter,

         gpointer       user_data)

{

   /* The two possibilities in this case for the "answer" variable are either

    * "on" or "off".

    */

   const gchar *answer = g_variant_get_string (parameter, NULL);

   /* We print the information to the user */

   g_printf ("State is set to %s.\n", answer);

   /* Note that we set the state of the action */

   g_simple_action_set_state (simple, parameter);

}

/* Callback function for the "awesome" action */

static void

awesome_callback (GSimpleAction *simple,

         GVariant      *parameter,

         gpointer       user_data)

{

  GVariant *action_state = g_action_get_state (G_ACTION (simple));

  gboolean active = g_variant_get_boolean (action_state);

  GVariant *new_state = g_variant_new_boolean (!active);

  /* Set the new state for the action.

   * (Keeps track of whether it was last checked or unchecked).

   */

  g_simple_action_set_state (simple, new_state);

  if (active)

     g_print ("You unchecked \"Awesome\"\n");

  else

     g_print ("You checked \"Awesome\"\n");

}

/* Startup function for the menu we are creating in this sample */

static void

startup (GApplication *app,

         gpointer      user_data)

{

  /* Initialize variables */

  GSimpleAction *new_action;

  GSimpleAction *quit_action;

  GSimpleAction *state_action;

  GSimpleAction *awesome_action;

  GtkBuilder *builder;

  GError *error = NULL;

  /* Begin creating the "new" action.

   * Note that it is an action without a state.

   */

  new_action = g_simple_action_new ("new", NULL);

  g_signal_connect (new_action, "activate", G_CALLBACK (new_callback), app);

  /* It is added to the overall application */

  g_action_map_add_action (G_ACTION_MAP (app), G_ACTION (new_action));

  /* Begin creating the "quit" action.

   * Note that it is an action without a state.

   */

  quit_action = g_simple_action_new ("quit", NULL);

  g_signal_connect (quit_action, "activate", G_CALLBACK (quit_callback), app);

  /* It is added to the overall application */

  g_action_map_add_action (G_ACTION_MAP (app), G_ACTION (quit_action));

  /* Begin creating the "state" action.

   * Note that it is an action with a state.

   */

  GVariantType *type_string2 = g_variant_type_new ("s");

  state_action = g_simple_action_new_stateful ("state", type_string2,

                                               g_variant_new_string ("off"));

  g_signal_connect (state_action, "activate", G_CALLBACK (state_callback), app);

  /* It is added to the overall application */

  g_action_map_add_action (G_ACTION_MAP (app), G_ACTION (state_action));

  g_variant_type_free (type_string2);

  /* Begin creating the "awesome" action.

   * Note that it is an action with a state.

   */

  awesome_action = g_simple_action_new_stateful ("awesome", NULL, g_variant_new_boolean (FALSE));

  g_signal_connect (awesome_action, "activate", G_CALLBACK (awesome_callback), app);

  /* It is added to the overall application */

  g_action_map_add_action (G_ACTION_MAP (app), G_ACTION (awesome_action));

  /* A builder to add the User Interface designed with GLADE to the grid: */

  builder = gtk_builder_new ();

  /* Get the file (if it is there):

   * Note: you must make sure that the file is in the current directory for

   * this to work. The function used here returns a non-null value within

   * our variable "error" if an error is indeed found.

   */

  gtk_builder_add_from_file (builder, "menubar.ui", &error);

  if (error != NULL) {

     g_print ("%s\n", error->message);

     g_error_free (error);

  }

  /* Extract the menubar */

  GObject *menubar = gtk_builder_get_object (builder, "menubar");

  gtk_application_set_menubar (GTK_APPLICATION (app), G_MENU_MODEL (menubar));

  /* Extract the appmenu */

  GObject *appmenu = gtk_builder_get_object (builder, "appmenu");

  gtk_application_set_app_menu (GTK_APPLICATION (app), G_MENU_MODEL (appmenu));

}

/* Startup function for the application */

int

main (int argc, char **argv)

{

  GtkApplication *app;

  int status;

  app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);

  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);

  g_signal_connect (app, "startup", G_CALLBACK (startup), NULL);

  status = g_application_run (G_APPLICATION (app), argc, argv);

  g_object_unref (app);

  return status;

}

Neste exemplo empregaremos o seguinte:

<list>

  <item>
<link href="http://developer.gnome.org/gtk3/stable/GtkApplication.html">GtkApplication</link>
</item>

  <item>
<link href="http://developer.gnome.org/gtk3/stable/GtkWindow.html">GtkWindow</link>
</item>

  <item>
<link href="http://developer.gnome.org/gio/stable/GSimpleAction.html">GSimpleAction</link>
</item>

  <item>
<link href="http://developer.gnome.org/gtk/stable/GtkAboutDialog.html">GtkAboutDialog</link>
</item>

  <item>
<link href="http://developer.gnome.org/glib/stable/glib-GVariantType.html">GtkVariantType</link>
</item>

</list>

</page>