#include <gtk/gtk.h>

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

  GtkWidget *window;
  GtkWidget *button;
  GtkWidget *halign;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window), "Tooltip");
  gtk_window_set_default_size(GTK_WINDOW(window), 300, 200);

  /*set border space around the edges of the window*/
  gtk_container_set_border_width(GTK_CONTAINER(window), 15);
  
  button = gtk_button_new_with_label("Button");

  /*set tooltop for widget*/
  gtk_widget_set_tooltip_text(button, "Button widget");

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

  /*flat the container to show all widgets at once*/
  gtk_widget_show_all(window);
  gtk_main();

  return 0;
}