title: gtk callback multiple arguments
body: <pre><code>#include &lt;gtk/gtk.h&gt;
  #include &lt;stdio.h&gt;
  
  typedef struct {
      const gchar *host;
  } example;
  
  void b_clicked (GtkButton *c_button, example *test){
      g_print("Hostname: %s\n", test-&gt;host);
  }
  
  int main (int argc, char *argv[]){
  
  GtkWidget *window;
  GtkWidget *grid;
  GtkWidget *c_button;
  GtkWidget *q_button;
  GtkWidget *label_host;
  GtkWidget *h_name;
  
  gtk_init (&amp;argc, &amp;argv);
  
  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title (GTK_WINDOW (window), "FTP Client");
  gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
  gtk_container_set_border_width (GTK_CONTAINER (window), 10);
  gtk_window_set_resizable(GTK_WINDOW(window), FALSE);
  
  grid = gtk_grid_new ();
  gtk_container_add (GTK_CONTAINER (window), grid);
  gtk_grid_set_row_spacing (GTK_GRID (grid), 3);
  
  label_host = gtk_label_new("Hostname");
  
  example test;
  h_name = gtk_entry_new();
  test.host = gtk_entry_get_text(GTK_ENTRY (h_name));
  gtk_entry_set_placeholder_text (GTK_ENTRY (h_name), "Hostname");
  c_button = gtk_button_new_with_label ("Connect");
  g_signal_connect (c_button, "clicked", G_CALLBACK (b_clicked), (gpointer*)&amp;test);
  q_button = gtk_button_new_with_label ("Quit");
  g_signal_connect (q_button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
  
  gtk_grid_attach (GTK_GRID (grid), label_host, 0, 0, 1, 1);
  gtk_grid_attach (GTK_GRID (grid), h_name, 1, 0, 1, 1);
  gtk_grid_attach (GTK_GRID (grid), c_button, 0, 3, 2, 1);
  gtk_grid_attach (GTK_GRID (grid), q_button, 0, 4, 2, 1);
  
  gtk_widget_show_all (window);
  
  gtk_main ();
  
  return 0;
  }
  </code></pre>
  
  <p>What is wrong whit this??<br>
  i have no errors and no warnings but on the terminal this program doesn't write anything :(<br>
  if i write:<br></p>
  
  <pre><code>test.host="trying something"
  </code></pre>
  
  <p>it works but with gtk_entry_get_text it doesn't show nothing :(<br>
  i don't understand...why it doesn't work with gtk_entry_get_text?</p>