c-gtksimple.h

// Kode sumber https://www.geeksforgeeks.org/how-to-create-gui-in-c-programming-using-gtk-toolkit/
#ifndef GTKSIMPLE
#define GTKSIMPLE
#include <gtk/gtk.h> 

static int counter = 0; 

void greet(GtkWidget* widget, gpointer data) 
{ 
    // printf equivalent in GTK+ 
    g_print("Welcome to GTK\n"); 
    g_print("%s clicked %d times\n", 
    (char*)data, ++counter); 
} 

void destroy(GtkWidget* widget, gpointer data) 
{ 
    gtk_main_quit(); 
} 

/// parameter masukan dihapus, argc dibuat 0, argv dibuat NULL
int main_gtksimple() 
{ 
    GtkWidget* window; 
    GtkWidget* button; 

    gtk_init(0, NULL); 
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL); 
    g_signal_connect(window, "destroy", G_CALLBACK(destroy), NULL); 

    /* Let's set the border width of the window to 20. 
    * You may play with the value and see the 
    * difference. */

    gtk_container_set_border_width(GTK_CONTAINER(window), 20); 
    button = gtk_button_new_with_label("Click Me!"); 
    /// Mengganti GTK_OBJECT dengan G_OBJECT
    g_signal_connect(G_OBJECT(button), "clicked", G_CALLBACK(greet), "button"); 

    gtk_container_add(GTK_CONTAINER(window), button); 
    gtk_widget_show_all(window); 
    gtk_main(); 

    return 0; 
}
#endif