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#include <gtk/gtk.h>
/* This is a callback function. The data arguments are ignored
* in this example. More on callbacks below.
*/
static void
print_hello (GtkWidget *widget,
gpointer data)
{
g_print ("Hello World\n");
}
static gboolean
on_delete_event (GtkWidget *widget,
GdkEvent *event,
gpointer data)
{
/* If you return FALSE in the "delete_event" signal handler,
* GTK will emit the "destroy" signal. Returning TRUE means
* you don't want the window to be destroyed.
*
* This is useful for popping up 'are you sure you want to quit?'
* type dialogs.
*/
g_print ("delete event occurred\n");
return TRUE;
}
int
main (int argc,
char *argv[])
{
/* GtkWidget is the storage type for widgets */
GtkWidget *window;
GtkWidget *button;
/* 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, and set its title */
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_title (GTK_WINDOW (window), "Hello");
/* When the window emits the "delete-event" signal (which is emitted
* by GTK+ in response to an event coming from the window manager,
* usually as a result of clicking the "close" window control), we
* ask it to call the on_delete_event() function as defined above.
*
* The data passed to the callback function is NULL and is ignored
* in the callback function.
*/
g_signal_connect (window, "delete-event", G_CALLBACK (on_delete_event), NULL);
/* Here we connect the "destroy" event to the gtk_main_quit() function.
*
* This signal is emitted when we call gtk_widget_destroy() on the window,
* or if we return FALSE in the "delete_event" callback.
*/
g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
/* Sets the border width of the window. */
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
/* Creates a new button with the label "Hello World". */
button = gtk_button_new_with_label ("Hello World");
/* When the button receives the "clicked" signal, it will call the
* function print_hello() passing it NULL as its argument.
*
* The print_hello() function is defined above.
*/
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
/* The g_signal_connect_swapped() function will connect the "clicked" signal
* of the button to the gtk_widget_destroy() function; instead of calling it
* using the button as its argument, it will swap it with the user data
* argument. This will cause the window to be destroyed by calling
* gtk_widget_destroy() on the window.
*/
g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_widget_destroy), window);
/* This packs the button into the window. A GtkWindow inherits from GtkBin,
* which is a special container that can only have one child
*/
gtk_container_add (GTK_CONTAINER (window), button);
/* The final step is to display this newly created widget... */
gtk_widget_show (button);
/* ... and the window */
gtk_widget_show (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;
}
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