title: Alternative to deprecated gtk_alignment_new
body: <p>I used the GtkAlignment widget to control the alignment and size of its child widget. But <code>gtk_alignment_new</code> has been deprecated since version 3.14 and should not be used in newly-written code. What functions should I use as alternatives to let the code be gtk3+ compatible?   </p>
  
  <pre><code>#include &lt;gtk/gtk.h&gt;
  
  int main(int argc, char *argv[]) {
  
    GtkWidget *window;
    GtkWidget *button;
    GtkWidget *halign;
  
    gtk_init(&amp;argc, &amp;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);
    gtk_container_set_border_width(GTK_CONTAINER(window), 15);
  
    button = gtk_button_new_with_label("Button");
    gtk_widget_set_tooltip_text(button, "Button widget");
  
    halign = gtk_alignment_new(0, 0, 0, 0);
    gtk_container_add(GTK_CONTAINER(halign), button);
    gtk_container_add(GTK_CONTAINER(window), halign);  
  
    gtk_widget_show_all(window);
  
    g_signal_connect(G_OBJECT(window), "destroy",
        G_CALLBACK(gtk_main_quit), NULL);  
  
    gtk_main();
  
    return 0;
  }
  </code></pre>