Add the async mail API (still not hooked up though)

svn path=/trunk/; revision=3676

6 files changed, 750 insertions, 2 deletions

diff --git a/mail/.cvsignore b/mail/.cvsignore
index 898d2ab6fc..63d45eccce 100644
--- a/mail/.cvsignore
+++ b/mail/.cvsignore
@@ -11,3 +11,4 @@ evolution-mail
 evolution-mail.pure
 test-mail
 test-sources
+test-thread
\ No newline at end of file
diff --git a/mail/ChangeLog b/mail/ChangeLog
index cc1f6f1679..69e4ffd4bc 100644
--- a/mail/ChangeLog
+++ b/mail/ChangeLog
@@ -1,4 +1,14 @@
-2000-06-21  Peter Williams  <peter@newton.cx>
+2000-06-21  Peter Williams  <peterw@helixcode.com>
+	* mail-thread.{c,h}: New files -- a simple API for executing
+	the major mail ops (fetch_mail etc) asynchronously, allowing
+	the operations to send messages and update a progress bar.
+
+	* test-thread.{c,h}: Tests the mail-thread API.
+
+	* Makefile.am: add mail-thread.[ch] to evolution_mail_SOURCES
+	and declare the test_thread noinst_PROGRAM.
+
+2000-06-21  Peter Williams  <peterw@helixcode.com>
 
 	* mail-format.c (mail_generate_reply): Include "e-setup.h" to
 	get the prototype for evolution_dir.
diff --git a/mail/Makefile.am b/mail/Makefile.am
index 51c7aa3150..e940eeed45 100644
--- a/mail/Makefile.am
+++ b/mail/Makefile.am
@@ -1,4 +1,4 @@
-bin_PROGRAMS =	evolution-mail test-mail
+bin_PROGRAMS =	evolution-mail test-mail test-thread
 
 providerdir = $(libdir)/evolution/camel-providers/$(VERSION)
 
@@ -45,6 +45,8 @@ evolution_mail_SOURCES =		\
 	mail-format.c			\
 	mail-identify.c			\
 	mail-ops.c			\
+	mail-threads.c			\
+	mail-threads.h			\
 	mail-types.h			\
 	main.c				\
 	message-list.c			\
@@ -67,6 +69,7 @@ evolution_mail_LDADD = 					\
 	$(top_builddir)/libibex/libibex.la		\
 	$(top_builddir)/filter/libfilter.la		\
 	$(BONOBO_HTML_GNOME_LIBS)			\
+	$(PTHREAD_LIB)					\
 	$(UNICODE_LIBS)
 
 test_mail_SOURCES = \
@@ -75,6 +78,16 @@ test_mail_SOURCES = \
 test_mail_LDADD = \
 	$(BONOBO_HTML_GNOME_LIBS)
 
+test_thread_SOURCES =	\
+	mail-threads.c	\
+	mail-threads.h	\
+	test-thread.c
+
+test_thread_LDADD = 			\
+	$(BONOBO_VFS_GNOME_LIBS)	\
+	$(PTHREAD_LIB)
+
+test_thread_CFLAGS = -g
 
 GOAD_FILES = evolution-mail.gnorba
 OAF_FILES = evolution-mail.oafinfo
diff --git a/mail/mail-threads.c b/mail/mail-threads.c
new file mode 100644
index 0000000000..ebd2570570
--- /dev/null
+++ b/mail/mail-threads.c
@@ -0,0 +1,566 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ * Author :
+ *  Peter Williams (peterw@helixcode.com)
+ *
+ *  Copyright 2000, Helix Code, Inc. (http://www.helixcode.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include <config.h>
+
+#include <string.h>
+#include <glib.h>
+#include "mail.h"
+#include "mail-threads.h"
+
+/* FIXME: support other thread types!!!! */
+#define USE_PTHREADS
+
+/**
+ * A function and its userdata
+ **/
+
+typedef struct closure_s {
+	void (*func)( gpointer );
+	gpointer data;
+} closure_t;
+
+/**
+ * A command issued through the compipe
+ **/
+
+typedef struct com_msg_s {
+	enum com_msg_type_e { STARTING, PERCENTAGE, HIDE_PBAR, SHOW_PBAR, MESSAGE, ERROR, FINISHED } type;
+	gfloat percentage;
+	gchar *message;
+} com_msg_t;
+
+/** 
+ * @mail_operation_in_progress: When true, there's
+ * another thread executing a major ev-mail operation:
+ * fetch_mail, etc.
+ *
+ * Because camel is not thread-safe we work
+ * with the restriction that more than one mailbox
+ * cannot be accessed at once. Thus we cannot
+ * concurrently check mail and move messages, etc.
+ **/
+
+static gboolean mail_operation_in_progress;
+
+/**
+ * @queue_window: The little window on the screen that
+ * shows the progress of the current operation and the
+ * operations that are queued to proceed after it.
+ *
+ * @queue_window_pending: The vbox that contains the
+ * list of pending operations.
+ *
+ * @queue_window_message: The label that contains the
+ * operation's message to the user
+ **/
+
+static GtkWidget *queue_window = NULL;
+static GtkWidget *queue_window_pending = NULL;
+static GtkWidget *queue_window_message = NULL;
+static GtkWidget *queue_window_progress = NULL;
+
+/**
+ * @op_queue: The list of operations the are scheduled
+ * to proceed after the currently executing one.
+ **/
+
+static GSList *op_queue = NULL;
+
+/**
+ * @compipe: The pipe through which the dispatcher communicates
+ * with the main thread for GTK+ calls
+ *
+ * @chan_reader: the GIOChannel that reads our pipe
+ */
+
+#define READER compipe[0]
+#define WRITER compipe[1]
+
+static int compipe[2] = { -1, -1 };
+
+GIOChannel *chan_reader = NULL;
+
+/**
+ * Static prototypes
+ **/
+
+static void create_queue_window( void );
+static void dispatch( closure_t *clur );
+static void *dispatch_func( void *data );
+static void check_compipe( void );
+static gboolean read_msg( GIOChannel *source, GIOCondition condition, gpointer userdata );
+static void remove_next_pending( void );
+
+/* Pthread code */
+#ifdef USE_PTHREADS
+
+#include <pthread.h>
+
+/**
+ * @dispatch_thread: the pthread_t (when using pthreads, of
+ * course) representing our dispatcher routine.
+ **/
+static pthread_t dispatch_thread;
+
+/* FIXME: do we need to set any attributes for our thread? */
+
+#else /* defined USE_PTHREADS */
+choke on this: no thread type defined
+#endif
+
+/**
+ * mail_operation_try:
+ * @description: A user-friendly string describing the operation.
+ * @callback: the function to call in another thread to start the operation
+ * @user_data: extra data passed to the callback
+ *
+ * Waits for the currently executing operation to finished, then
+ * executes the callback function in another thread. Returns TRUE
+ * on success, FALSE on some sort of queueing error.
+ **/
+
+gboolean
+mail_operation_try( const gchar *description, void (*callback)( gpointer ), gpointer user_data )
+{
+	closure_t *clur;
+	g_assert( callback );
+
+	clur = g_new( closure_t, 1 );
+	clur->func = callback;
+	clur->data = user_data;
+
+	if( mail_operation_in_progress == FALSE ) {
+		/* We got the lock. Yippeee! This means that no operations
+		 * are pending, either, so we'll create the queue window and
+		 * show only the message and progress bar.
+		 */
+
+		mail_operation_in_progress = TRUE;
+
+		check_compipe();
+		create_queue_window();
+		gtk_widget_show_all( queue_window );
+		gnome_win_hints_set_layer( queue_window, 
+					   WIN_LAYER_ONTOP );
+		gnome_win_hints_set_state( queue_window, 
+					   WIN_STATE_ARRANGE_IGNORE );
+		gnome_win_hints_set_hints( queue_window, 
+					   WIN_HINTS_SKIP_FOCUS |
+					   WIN_HINTS_SKIP_WINLIST |
+					   WIN_HINTS_SKIP_TASKBAR );
+		gtk_widget_hide( queue_window_pending );
+
+		dispatch( clur );
+	} else {
+		GtkWidget *label;
+
+		/* Zut. We already have an operation running. Well,
+		 * queue ourselves up. */
+		
+		/* Yes, prepend is faster. But we pop operations
+		 * off the beginning later and that's a lot easier.
+		 */
+
+		op_queue = g_slist_append( op_queue, clur );
+
+		/* Show us in the pending window. */
+		label = gtk_label_new( description );
+		gtk_misc_set_alignment( GTK_MISC( label ), 1.0, 0.5 );
+		gtk_box_pack_start( GTK_BOX( queue_window_pending ), label,
+				    TRUE, TRUE, 2 );
+
+		/* If we want the next op to be on the bottom, uncomment this */
+		/* 1 = first on list always (0-based) */
+		/* gtk_box_reorder_child( GTK_BOX( queue_window_pending ), label, 1 ); */
+		gtk_widget_show_all( queue_window_pending );
+	}
+
+	return TRUE;
+}
+
+/**
+ * mail_op_set_percentage:
+ * @percentage: the percentage that will be displayed in the progress bar
+ *
+ * Set the percentage of the progress bar for the currently executing operation.
+ * Threadsafe for, nay, intended to be called by, the dispatching thread.
+ **/
+
+void mail_op_set_percentage( gfloat percentage )
+{
+	com_msg_t msg;
+
+	msg.type = PERCENTAGE;
+	msg.percentage = percentage;
+	write( WRITER, &msg, sizeof( msg ) );
+}
+
+/**
+ * mail_op_hide_progressbar:
+ *
+ * Hide the progress bar in the status box
+ * Threadsafe for, nay, intended to be called by, the dispatching thread.
+ **/
+
+/* FIXME: I'd much rather have one of those Netscape-style progress
+ * bars that just zips back and forth, but gtkprogressbar can't do
+ * that, right? 
+ */
+
+void mail_op_hide_progressbar( void )
+{
+	com_msg_t msg;
+
+	msg.type = HIDE_PBAR;
+	write( WRITER, &msg, sizeof( msg ) );
+}
+
+/**
+ * mail_op_show_progressbar:
+ *
+ * Show the progress bar in the status box
+ * Threadsafe for, nay, intended to be called by, the dispatching thread.
+ **/
+
+void mail_op_show_progressbar( void )
+{
+	com_msg_t msg;
+
+	msg.type = SHOW_PBAR;
+	write( WRITER, &msg, sizeof( msg ) );
+}
+
+/**
+ * mail_op_set_message:
+ * @fmt: printf-style format string for the message
+ * @...: arguments to the format string
+ *
+ * Set the message displayed above the progress bar for the currently
+ * executing operation.
+ * Threadsafe for, nay, intended to be called by, the dispatching thread.
+ **/
+
+void mail_op_set_message( gchar *fmt, ... )
+{
+	com_msg_t msg;
+	va_list val;
+
+	va_start( val, fmt );
+	msg.type = MESSAGE;
+	msg.message = g_strdup_vprintf( fmt, val );
+	va_end( val );
+
+	write( WRITER, &msg, sizeof( msg ) );
+}
+
+/**
+ * mail_op_error:
+ * @fmt: printf-style format string for the error
+ * @...: arguments to the format string
+ *
+ * Opens an error dialog for the currently executing operation.
+ * Threadsafe for, nay, intended to be called by, the dispatching thread.
+ **/
+
+void mail_op_error( gchar *fmt, ... )
+{
+	com_msg_t msg;
+	va_list val;
+
+	va_start( val, fmt );
+	msg.type = ERROR;
+	msg.message = g_strdup_vprintf( fmt, val );
+	va_end( val );
+
+	write( WRITER, &msg, sizeof( msg ) );
+}
+
+/**
+ * mail_operation_wait_for_finish:
+ *
+ * Waits for the currently executing async operations
+ * to finish executing
+ */
+
+void mail_operation_wait_for_finish( void )
+{
+	while( mail_operation_in_progress ) {
+		while( gtk_events_pending() )
+			gtk_main_iteration();
+	}
+}
+
+/* ** Static functions **************************************************** */
+
+/**
+ * create_queue_window:
+ *
+ * Creates the queue_window widget that displays the progress of the
+ * current operation.
+ */
+
+static void
+create_queue_window( void )
+{
+	GtkWidget *vbox;
+	GtkWidget *pending_vb, *pending_lb;
+	GtkWidget *progress_lb, *progress_bar;
+
+	/* Check to see if we've only hidden it */
+	if( queue_window != NULL )
+		return;
+
+	queue_window = gtk_window_new( GTK_WINDOW_DIALOG );
+	gtk_container_set_border_width( GTK_CONTAINER( queue_window ), 8 );
+
+	vbox = gtk_vbox_new( FALSE, 4 );
+
+	pending_vb = gtk_vbox_new( TRUE, 2 );
+	queue_window_pending = pending_vb;
+
+	pending_lb = gtk_label_new( _("Currently pending operations:") );
+	gtk_misc_set_alignment( GTK_MISC( pending_lb ), 0.0, 0.0 );
+	gtk_box_pack_start( GTK_BOX( pending_vb ), pending_lb,
+			    TRUE, TRUE, 0 );
+
+	gtk_box_pack_start( GTK_BOX( vbox ), pending_vb,
+			    TRUE, TRUE, 4 );
+
+	/* FIXME: 'operation' is not the warmest cuddliest word. */
+	progress_lb = gtk_label_new( _("Starting operation...") );
+	queue_window_message = progress_lb;
+	gtk_box_pack_start( GTK_BOX( vbox ), progress_lb,
+			    TRUE, TRUE, 4 );
+
+	progress_bar = gtk_progress_bar_new();
+	queue_window_progress = progress_bar;
+	/* FIXME: is this fit for l10n? */
+	gtk_progress_bar_set_orientation( GTK_PROGRESS_BAR( progress_bar ), 
+					  GTK_PROGRESS_LEFT_TO_RIGHT );
+	gtk_progress_bar_set_bar_style( GTK_PROGRESS_BAR( progress_bar ), 
+					GTK_PROGRESS_CONTINUOUS );
+	gtk_box_pack_start( GTK_BOX( vbox ), progress_bar,
+			    TRUE, TRUE, 4 );
+
+	gtk_container_add( GTK_CONTAINER( queue_window ), vbox );
+}
+
+/**
+ * check_compipe:
+ *
+ * Check and see if our pipe has been opened and open
+ * it if necessary.
+ **/
+
+static void check_compipe( void )
+{
+	if( READER > 0 )
+		return;
+
+	if( pipe( compipe ) < 0 ) { 
+		g_warning( "Call to pipe(2) failed!" );
+		
+		/* FIXME: better error handling. How do we react? */
+		return;
+	}
+
+	chan_reader = g_io_channel_unix_new( READER );
+	g_io_add_watch( chan_reader, G_IO_IN, read_msg, NULL );
+}
+
+/**
+ * dispatch:
+ * @clur: The function to execute and its userdata
+ *
+ * Start a thread that executes the closure and exit
+ * it when done.
+ */
+
+static void dispatch( closure_t *clur )
+{
+	int res;
+
+	res = pthread_create( &dispatch_thread, NULL, (void *) &dispatch_func, clur );
+
+	if( res != 0 ) {
+		g_warning( "Error launching dispatch thread!" );
+		/* FIXME: more error handling */
+	}
+}
+
+/**
+ * dispatch_func:
+ * @data: the closure to run
+ *
+ * Runs the closure and exits the thread.
+ */
+
+static void *dispatch_func( void *data )
+{
+	com_msg_t msg;
+	closure_t *clur = (closure_t *) data;
+
+	msg.type = STARTING;
+	write( WRITER, &msg, sizeof( msg ) );
+
+	(clur->func)( clur->data );
+
+	msg.type = FINISHED;
+	write( WRITER, &msg, sizeof( msg ) );
+
+	g_free( data );
+
+	pthread_exit( 0 );
+	return NULL; /*NOTREACHED*/
+}
+
+/**
+ * read_msg:
+ * @userdata: unused
+ *
+ * A message has been recieved on our pipe; perform the appropriate 
+ * action.
+ **/
+
+static gboolean read_msg( GIOChannel *source, GIOCondition condition, gpointer userdata )
+{
+	com_msg_t msg;
+	closure_t *clur;
+	GSList *temp;
+	guint size;
+	#if 0
+	GtkWidget *err_dialog;
+	#else
+	gchar *errmsg;
+	#endif
+
+	g_io_channel_read( source, (gchar *) &msg, 
+			   sizeof( msg ) / sizeof( gchar ), 
+			   &size );
+
+	if( size != sizeof( msg ) ) {
+		g_warning( _("Incomplete message written on pipe!") );
+		msg.type = ERROR;
+		msg.message = g_strdup( _("Error reading commands from dispatching thread.") );
+	}
+
+	switch( msg.type ) {
+	case STARTING:
+		gtk_label_set_text( GTK_LABEL( queue_window_message ),
+				    _("Starting operation...") );
+		gtk_progress_bar_update( GTK_PROGRESS_BAR( queue_window_progress ), 0.0 );
+		break;
+	case PERCENTAGE:
+		gtk_progress_bar_update( GTK_PROGRESS_BAR( queue_window_progress ), msg.percentage );
+		break;
+	case HIDE_PBAR:
+		gtk_widget_hide( GTK_WIDGET( queue_window_progress ) );
+		break;
+	case SHOW_PBAR:
+		gtk_widget_show( GTK_WIDGET( queue_window_progress ) );
+		break;
+	case MESSAGE:
+		gtk_label_set_text( GTK_LABEL( queue_window_message ),
+				    msg.message );
+		g_free( msg.message );
+		break;
+	case ERROR:
+		#if 0
+		/* FIXME FIXME: the gnome_dialog_ functions are causing coredumps
+		 * on my machine! Every time, threads or not... "IMLIB ERROR: Cannot
+		 * allocate XImage buffer". Until then, work around
+		 */
+		err_dialog = gnome_error_dialog( msg.message );
+		gnome_dialog_run_and_close( GNOME_DIALOG( err_dialog ) );
+		#else
+		errmsg = g_strdup_printf( "ERROR: %s", msg.message );
+		gtk_label_set_text( GTK_LABEL( queue_window_message ),
+				    errmsg );
+		g_free( errmsg );
+		#endif
+		g_free( msg.message );
+		break;
+		/* Don't fall through; dispatch_func does the FINISHED
+		 * call for us 
+		 */
+	case FINISHED:
+		if( op_queue == NULL ) {
+			/* All done! */
+			gtk_widget_hide( queue_window );
+			mail_operation_in_progress = FALSE;
+		} else {
+			/* There's another operation left */
+			
+			/* Pop it off the front */
+			clur = op_queue->data;
+			temp = g_slist_next( op_queue );
+			g_slist_free_1( op_queue );
+			op_queue = temp;
+
+			/* Clear it out of the 'pending' vbox */
+			remove_next_pending();
+
+			/* Run run run little process */
+			dispatch( clur );
+		}
+		break;
+	default:
+		g_warning( _("Corrupted message from dispatching thread?") );
+		break;
+	}
+
+	return TRUE;
+}
+
+/**
+ * remove_next_pending:
+ *
+ * Remove an item from the list of pending items. If
+ * that's the last one, additionally hide the little
+ * 'pending' message.
+ **/
+
+static void remove_next_pending( void )
+{
+	GList *children;
+
+	children = gtk_container_children( GTK_CONTAINER( queue_window_pending ) );
+
+	/* Skip past the header label */
+	children = g_list_first( children );
+	children = g_list_next( children );
+
+	/* Nuke the one on top */
+	gtk_container_remove( GTK_CONTAINER( queue_window_pending ),
+			      GTK_WIDGET( children->data ) );
+
+	/* Hide it? */
+	if( g_list_next( children ) == NULL )
+		gtk_widget_hide( queue_window_pending );
+
+	/* FIXME: The window gets really messed up here */
+	gtk_container_resize_children( GTK_CONTAINER( queue_window_pending ) );
+	gtk_container_resize_children( GTK_CONTAINER( queue_window ) );
+}
diff --git a/mail/mail-threads.h b/mail/mail-threads.h
new file mode 100644
index 0000000000..89fa439fa9
--- /dev/null
+++ b/mail/mail-threads.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ * Author :
+ *  Peter Williams (peterw@helixcode.com)
+ *
+ *  Copyright 2000, Helix Code, Inc. (http://www.helixcode.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef _MAIL_THREADS_H_
+#define _MAIL_THREADS_H_
+
+/* Schedule to operation to happen eventually */
+
+gboolean mail_operation_try( const gchar *description, 
+			     void (*callback)( gpointer ), 
+			     gpointer user_data );
+
+/* User interface hooks for the other thread */
+
+void mail_op_set_percentage( gfloat percentage );
+void mail_op_hide_progressbar( void );
+void mail_op_show_progressbar( void );
+void mail_op_set_message( gchar *fmt, ... ) G_GNUC_PRINTF( 1, 2 );
+void mail_op_error( gchar *fmt, ... ) G_GNUC_PRINTF( 1, 2 );
+
+/* Wait for the async operations to finish */
+void mail_operation_wait_for_finish( void );
+
+#endif /* defined _MAIL_THREADS_H_ */
diff --git a/mail/test-thread.c b/mail/test-thread.c
new file mode 100644
index 0000000000..f2b46be763
--- /dev/null
+++ b/mail/test-thread.c
@@ -0,0 +1,113 @@
+/* Tests the multithreaded UI code */
+
+#include "config.h"
+#include <unistd.h>
+#include <glib.h>
+#include <gtk/gtk.h>
+#include <stdio.h>
+#include "mail-threads.h"
+
+static void op_1( gpointer userdata );
+static void op_2( gpointer userdata );
+static void op_3( gpointer userdata );
+static void op_4( gpointer userdata );
+static gboolean queue_ops( void );
+
+static gboolean queue_ops( void )
+{
+	int i;
+	gchar buf[32];
+
+	g_message( "Top of queue_ops" );
+
+	mail_operation_try( "The Crawling Progress Bar of Doom", op_1, NULL );
+	mail_operation_try( "The Mysterious Message Setter", op_2, NULL );
+	mail_operation_try( "The Error Dialog of No Return", op_3, NULL );
+
+	for( i = 0; i < 7; i++ ) {
+		sprintf( buf, "Queue Filler %d", i );
+		mail_operation_try( buf, op_4, GINT_TO_POINTER( i ) );
+	}
+
+	g_message( "Waiting for finish..." );
+	mail_operation_wait_for_finish();
+
+	g_message( "Ops done -- queue some more!" );
+
+	mail_operation_try( "Progress Bar Redux", op_1, NULL );
+
+	g_message( "Waiting for finish again..." );
+	mail_operation_wait_for_finish();
+
+	g_message( "Ops done -- more, more!" );
+
+	for( i = 0; i < 3; i++ ) {
+		sprintf( buf, "Queue Filler %d", i );
+		mail_operation_try( buf, op_4, GINT_TO_POINTER( i ) );
+	}
+
+	g_message( "Waiting for finish AGAIN..." );
+	mail_operation_wait_for_finish();
+	g_message( "Ops done again. Exiting 0" );
+	gtk_exit( 0 );
+	return FALSE;
+}
+
+static void op_1( gpointer userdata )
+{
+	gfloat pct;
+
+	mail_op_show_progressbar();
+	mail_op_set_message( "Watch the progress bar!" );
+
+	for( pct = 0.0; pct < 1.0; pct += 0.1 ) {
+		sleep( 1 );
+		mail_op_set_percentage( pct );
+	}
+}
+
+static void op_2( gpointer userdata )
+{
+	int i;
+
+	mail_op_hide_progressbar();
+	for( i = 10; i > 0; i-- ) {
+		mail_op_set_message( "%d", i );
+		sleep( 1 );
+	}
+
+	mail_op_set_message( "BOOOM!" );
+	sleep( 1 );
+}
+
+static void op_3( gpointer userdata )
+{
+	gfloat pct;
+
+	mail_op_show_progressbar();
+	mail_op_set_message( "Frobulating the foosamatic" );
+
+	for( pct = 0.0; pct < 0.3; pct += 0.1 ) {
+		mail_op_set_percentage( pct );
+		sleep( 1 );
+	}
+
+	mail_op_error( "Oh no! The foosamatic was booby-trapped!" );
+	sleep( 1 );
+}
+
+static void op_4( gpointer userdata )
+{
+	mail_op_hide_progressbar();
+	mail_op_set_message( "Filler # %d", GPOINTER_TO_INT( userdata ) );
+	sleep( 1 );
+}
+
+int main( int argc, char **argv )
+{
+	g_thread_init( NULL );
+	gtk_init( &argc, &argv );
+	gtk_idle_add( (GtkFunction) queue_ops, NULL );
+	gtk_main();
+	return 0;
+}