gtk grid add two widgets

Question

I have this code:

/* Descrizione: GUI Client FTP sviluppato come progetto per il corso di Reti di Calcolatori (laurea SSRI presso DTI Crema)
 * Sviluppatori: Paolo Stivanin, Filippo Roncari, Stefano Agostini.
 * Anno: 2012
 * Licenza: GNU AGPL v3 <http://www.gnu.org/licenses/agpl-3.0.html>
 * Sito web: <https://github.com/polslinux/FTPUtils> */

#include <gtk/gtk.h>

/* When "connect" button is clicked a message will appear */
static void print_hello (GtkWidget *widget, gpointer data)
{
  g_print ("Connect button clicked\n");
}

int main (int argc, char *argv[]){

/* Declare widgets */
GtkWidget *window;
GtkWidget *grid;
GtkWidget *button;
GtkWidget *u_name;
GtkWidget *h_name;
GtkWidget *pass;
GtkWidget *label_user;
GtkWidget *label_host;
GtkWidget *label_pass;

/*This is called in all GTK applications. Arguments are parsed from the command line and are returned to the application.*/
gtk_init (&argc, &argv);

/* create a new window, set its title and put it on center */
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_title (GTK_WINDOW (window), "FTP Client");
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
gtk_window_set_resizable(GTK_WINDOW(window), FALSE); /* window is NOT resizable */

/* Here we construct the container that is going pack our buttons */
grid = gtk_grid_new ();
gtk_grid_set_row_spacing (GTK_GRID (grid), 3);

/* Pack the container in the window */
gtk_container_add (GTK_CONTAINER (window), grid);

/* Add labels */
label_user = gtk_label_new("Username  ");
label_host = gtk_label_new("Hostname  ");
label_pass = gtk_label_new("Password  ");

/* Add hostname entry and label */
h_name = gtk_entry_new();
gtk_entry_set_placeholder_text (GTK_ENTRY (h_name), "Hostname"); /* imposto il testo trasparente che scompare quando clicco o scrivo */
gtk_grid_attach (GTK_GRID (grid), label_host, 0, 0, 1, 1);
gtk_grid_attach (GTK_GRID (grid), h_name, 1, 0, 1, 1);

/* Add username entry and label */
u_name = gtk_entry_new();
gtk_entry_set_placeholder_text (GTK_ENTRY (u_name), "Username");
gtk_grid_attach (GTK_GRID (grid), label_user, 0, 1, 1, 1);
gtk_grid_attach (GTK_GRID (grid), u_name, 1, 1, 2, 1);

/* Add password entry and label (visibility set to 0 = not visible */
pass = gtk_entry_new();
gtk_entry_set_placeholder_text (GTK_ENTRY (pass), "Password");
gtk_grid_attach (GTK_GRID (grid), label_pass, 0, 2, 1, 1);
gtk_entry_set_visibility (GTK_ENTRY (pass), 0);
gtk_grid_attach (GTK_GRID (grid), pass, 1, 2, 1, 1);

/* Add connect button */
button = gtk_button_new_with_label ("Connect");
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
gtk_grid_attach (GTK_GRID (grid), button, 0, 3, 2, 1);

/* Add quit button */
button = gtk_button_new_with_label ("Quit");
g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
gtk_grid_attach (GTK_GRID (grid), button, 0, 4, 2, 1);

/* Now that we are done packing our widgets, we show them all in one go, by calling gtk_widget_show_all() on the window.*/
gtk_widget_show_all (window);

/* All GTK applications must have a gtk_main(). Control ends here and waits for an event to occur (like a key press or a mouse event),
 * until gtk_main_quit() is called. */
gtk_main ();

return 0;
}

And i want to add more widgets...how can i do it? For example i want to add a menubar (with About menu for example) but if i do:

gtk_container_add (GTK_CONTAINER (window), menubar);

the compiler tell me that i cannot add more than 1 widget into window...

I'm developing the gui with GTK+ v3.4.1 on Ubuntu 12.04!

Answer 1

You have to add the second widget to the grid, not the window. The window can contain only one widget, in this case the grid. The grid can contain more than one widget.