Re: Problem with GtkProgressBar and multi thread application

[Jorge Navalon <jorge navalon gmail com>]

On Sun, 2006-12-24 at 00:26 +0100, Tomasz Jankowski wrote:
> Hello!
>
> This is simple code:
> #include <gtk/gtk.h>
>
> gboolean pulse_it (gpointer data)   {
>     gtk_progress_bar_pulse (data);
>     return TRUE;
> }
>
> gint thread_fun (gpointer data) {
>     gint source_id = g_timeout_add (100, (GSourceFunc) pulse_it, data);
>
>     g_usleep (5000000);
>
>     g_source_remove (source_id);
>
>     gdk_threads_enter ();
>     gtk_progress_bar_set_text (data, "lol!");
>     gdk_threads_leave ();
> }
>
> int main( int   argc,
>           char *argv[])
> {
>     GtkWidget    *window;
>     GtkWidget   *pbar;
>
>     gtk_init (&argc, &argv);
>
>     g_thread_init (NULL);
>
>     window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
>     pbar = gtk_progress_bar_new ();
>
>     gtk_container_add (GTK_CONTAINER (window), GTK_WIDGET (pbar));
>
>     gtk_widget_show_all (window);
>
>     g_thread_create (thread_fun, pbar, FALSE, NULL);
>
>     gdk_threads_enter ();
>     gtk_main ();
>     gdk_threads_leave ();
>
>     return 0;
> }
>
>
> It doesn't work form me. Progress bar is pulsing, but when event source is
> removed something weird starts happening. Whole application still works, but
> GUI doesn't update (new progress bar's text doesn't display). Any idea how
> to solve this?! Maybe I'm too stupid...
>
> I use Ubuntu with GTK+v.2.10.6, GLib 2.12.4 and GCC 4.1

I'm no expert in either gtk or threads, but this seems to be the most
usual way to solve your problem:

*change your function so it doesn't require to use gdk_threads_...:


gint thread_fun (gpointer data) {
    gint source_id = g_timeout_add (100, (GSourceFunc) pulse_it, data);

    g_usleep (5000000);

    g_source_remove (source_id);
    
   source_id = g_timeout_add(0, (GSourceFunc) set_lol_text, data);

   // gdk_threads_enter ();
    //gtk_progress_bar_set_text (data, "lol!");
    //gdk_threads_leave ();
}

*add a new function to change the text. This function returns FALSE
indicating that it must be called only once:

gboolean set_lol_text (gpointer data)   {
        gtk_progress_bar_set_text (data, "LOL!");
        return FALSE;
}

I hope this helps.