# Hello World (C)

Susanna Huhtanen
ihmis.suski@gmail.com 2012
Tiffany Antopolski
tiffany.antopolski@gmail.com
Bastian Ilsø
bastianilso@gnome.org
Creating a small "Hello, World" application using GTK+.
Fran Dieguez
frandieguez@gnome.org 2012-2013.

# Hello world

For a detailed walk-through of creating a GTK+ dialog in C, see Getting Started with GTK+

Writing a hello world GTK+ dialog in C can be done as seen in the code sample below:

#include <gtk/gtk.h>

static void activate (GtkApplication* app, gpointer user_data) { GtkWidget *window; GtkWidget *label;

window = gtk_application_window_new (app); label = gtk_label_new ("Hello GNOME!"); gtk_container_add (GTK_CONTAINER (window), label); gtk_window_set_title (GTK_WINDOW (window), "Welcome to GNOME"); gtk_window_set_default_size (GTK_WINDOW (window), 200, 100); gtk_widget_show_all (window); }

int main (int argc, char **argv) { GtkApplication *app; int status;

app = gtk_application_new (NULL, G_APPLICATION_FLAGS_NONE); g_signal_connect (app, "activate", G_CALLBACK (activate), NULL); status = g_application_run (G_APPLICATION (app), argc, argv); g_object_unref (app);

return status; }

GtkApplication initializes GTK+. It also connects the x button that's automatically generated along with the window to the "destroy" signal. We can start building our first window. We do this by creating a variable called window and assigning it a gtk_application_window_new. The window title can be any string you want it to be. To be on the safe side, it's best to stick to UTF-8 encoding. The code above will create a dialog window similar to what can be seen below: