Re: Bypassing Force Quit

[David Nečas (Yeti) <yeti physics muni cz>]

On Wed, May 16, 2007 at 02:19:19PM -0400, Dan Gruhn wrote:
> I am running on FedoraCore5 and I have an application that when the user 
> clicks the "X" in the upper right wants to query for saving any changed 
> data.  I have currently coded this as a signal handler for the delete 
> event which puts up a modal dialog box with the questions and waits for 
> the user's response.  However, after some internal timeout, I get 
> another dialog box warning me that the window titled "..." is not 
> responding and do I want to force it to quit, losing all of my data.
>
> I would like to disable this if possible, but I've not yet found a way.  
> Is this caused by GTK?  Has anyone encountered this and have you found a 
> way around it?

You are probably doing something wrong.  As you can try
yourself, this program

======================================================
#include <gtk/gtk.h>

static gboolean
deleted(GtkWindow *window)
{
    GtkWidget *dialog;
    gint response;

    dialog = gtk_message_dialog_new(window, 0,
                                    GTK_MESSAGE_QUESTION,
                                    GTK_BUTTONS_YES_NO,
                                    "Really close window?");
    response = gtk_dialog_run(GTK_DIALOG(dialog));
    gtk_widget_destroy(dialog);

    return response == GTK_RESPONSE_NO;
}

int
main(int argc, char *argv[])
{
    GtkWidget *window, *widget;

    gtk_init(&argc, &argv);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_default_size(GTK_WINDOW(window), 400, 300);

    widget = gtk_label_new("Try to close me");
    gtk_container_add(GTK_CONTAINER(window), widget);
    gtk_widget_show_all(window);
    g_signal_connect(G_OBJECT(window), "delete-event",
                     G_CALLBACK(deleted), NULL);
    g_signal_connect(G_OBJECT(window), "destroy", gtk_main_quit, NULL);

    gtk_main();

    return 0;
}
======================================================

does exactly what you describe, yet it does not raise any
`force quit' dialog.  While this is no hard proof, it still
supports the theory if you let Gtk+ main loop run it
properly responds to anything the window manager may want
a response to.

However, if one replaces the body of deleted() with
sleep(3), metacity indeed starts complaininig about
a non-responsive application with the `force quit' dialog.
This is because the window does not respond to the ping sent
after delete events in 2.25 second now (the timeout value
seems to be hardwired in metacity).

Usually there is no reason why a yes/no dialog construction
should take several seconds.  And even if there is, your
application should not become non-responsive for such a long
time, so do the necessary work in a way that lets Gtk+ main
loop to run.

Yeti

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