Making Windows Busy

[Anthony Edward Cooper <aecooper coosoft plus com>]

   Hi all,

I'm writing a GTK2 Perl application and I am trying to write a routine 
that will make a window busy, i.e. display the busy cursor and stop all 
input events (keyboard and mouse clicks, but not move movement) from 
going to the window).

This is using Perl version 5.8.5 on WhiteBox 4 respin 1 (clone of RHAS4U3).

I include the following:

use strict;
use Glib qw(FALSE TRUE);
use Gnome2;
use Gnome2::VFS -init;
use Gtk2 -init;
set_locale Gtk2;
init Gtk2;
use Gtk2::GladeXML;
use Gtk2::Helper;
use Gtk2::Pango;
use Gtk2::SourceView;
use IPC::Open3;
use Monotone::AutomateStdio;
use POSIX qw(:errno_h :sys_wait_h);
use POSIX qw(strftime);

I use the following routine to update the display when inside a callback 
that is busy doing some processing:

sub gtk2_update()
{

   return if (Gtk2->main_level() == 0);
   while (Gtk2->events_pending())
   {
       Gtk2->main_iteration();
   }

}

and the following to make a window busy/unbusy:

sub make_busy($$)
{

   my($instance, $busy) = @_;

   # Create and store the cursors if we haven't done so already.

   if (! exists($instance->{busy_cursor}))
   {
       $instance->{normal_cursor} = Gtk2::Gdk::Cursor->new("left-ptr");
       $instance->{busy_cursor} = Gtk2::Gdk::Cursor->new("watch");
   }

   # Do it. Make the application bar grab the input when the window is 
busy,
   # that way we gobble up keyboard and mouse events that could muck up the
   # application state.

   if ($busy)
   {
       $instance->{window}->window()->set_cursor($instance->{busy_cursor});
       Gtk2->grab_add($instance->{appbar});
   }
   else
   {
       $instance->{window}->window()->
           set_cursor($instance->{normal_cursor});
       Gtk2->grab_remove($instance->{appbar});
   }

}

This sort of works. However if the mouse cursor is moved to a widget 
whilst the window is busy, then the window is made unbusy, the user has 
to move the cursor away from the widget and then back again before it 
will respond to a button click (I suspect because the movement was lost 
along with everything else).

I have tried to interrupt the flow of events by writing my own main 
event loop but that didn't work very well. I'm sure there is an easy 
answer as it is a common thing to want to do but I can't find anything 
on this. Any ideas?

MTIA,

Tony Cooper.