#include <gtk/gtk.h>

void print_msg(GtkWidget *widget, gpointer window) {

  g_print("Button clicked\n");
}

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

  GtkWidget *window;
  GtkWidget *button;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window), "Mnemonic");
  gtk_window_set_default_size(GTK_WINDOW(window), 300, 200);
  gtk_container_set_border_width(GTK_CONTAINER(window), 15);

  /*set mnemonic*/
  button = gtk_button_new_with_mnemonic("_Button");

  /*connect signal with callback fct print_msg*/
  g_signal_connect(button, "clicked", 
      G_CALLBACK(print_msg), NULL);  
  
  /*source:https://stackoverflow.com/questions/58746046/alternative-to-deprecated-gtk-alignment-new*/
  gtk_widget_set_halign (button, GTK_ALIGN_START);
  gtk_widget_set_valign (button, GTK_ALIGN_START);

  gtk_container_add(GTK_CONTAINER(window), button);

  gtk_widget_show_all(window);
  
  g_signal_connect(G_OBJECT(window), "destroy",
      G_CALLBACK(gtk_main_quit), NULL); 

  gtk_main();

  return 0;
}