Here is a port of SDLvncviewer to GTK+2.

I think it may encourage people to implement more features for the viewer,
because a GTK GUI seems to be easier to implement than a SDL one
(and it is more integrated with the major Linux Desktops out there).

Signed-off-by: Christian Beier <dontmind@freeshell.org>

4 files changed, 683 insertions, 3 deletions

diff --git a/AUTHORS b/AUTHORS
index 6152955..4f2a1fc 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -34,8 +34,8 @@ Alessandro Praduroux, Brad Hards, Timo Ketola, Christian Ehrlicher,
 Noriaki Yamazaki, Ben Klopfenstein, Vic Lee, Christian Beier,
 Alexander Dorokhine, Corentin Chary, Wouter Van Meir, George Kiagiadakis,
 Joel Martin, Gernot Tenchio, William Roberts, Cristian Rodríguez,
-George Fleury, Kan-Ru Chen, Steve Guo, Luca Stauble, Peter Watkins and
-Kyle J. McKay.
+George Fleury, Kan-Ru Chen, Steve Guo, Luca Stauble, Peter Watkins,
+Kyle J. McKay and Mateus Cesar Groess.
 
 Probably I forgot quite a few people sending a patch here and there, which
 really made a difference. Without those, some obscure bugs still would
diff --git a/client_examples/Makefile.am b/client_examples/Makefile.am
index 8619dc2..2779d53 100644
--- a/client_examples/Makefile.am
+++ b/client_examples/Makefile.am
@@ -28,7 +28,15 @@ endif
 SDLvncviewer_LDADD=$(LDADD) $(SDL_LIBS) $(X11_LIB)
 endif
 
-noinst_PROGRAMS=ppmtest $(SDLVIEWER) $(FFMPEG_CLIENT) backchannel
+if HAVE_LIBGTK
+GTKVIEWER=gtkvncviewer
+gtkvncviewer_SOURCES=gtkvncviewer.c
+gtkvncviewer_CFLAGS=$(GTK_CFLAGS)
+gtkvncviewer_LDADD=$(LDADD) $(GTK_LIBS)
+endif
+
+
+noinst_PROGRAMS=ppmtest $(SDLVIEWER) $(GTKVIEWER) $(FFMPEG_CLIENT) backchannel
 
 
 
diff --git a/client_examples/gtkvncviewer.c b/client_examples/gtkvncviewer.c
new file mode 100644
index 0000000..9e9e72b
--- /dev/null
+++ b/client_examples/gtkvncviewer.c
@@ -0,0 +1,668 @@
+
+/*
+ * Copyright (C) 2007 - Mateus Cesar Groess
+ *
+ * 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 Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <stdlib.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+#include <rfb/rfbclient.h>
+
+static rfbClient *cl;
+static gchar *server_cut_text = NULL;
+static gboolean framebuffer_allocated = FALSE;
+
+/* Redraw the screen from the backing pixmap */
+static gboolean expose_event (GtkWidget      *widget,
+                              GdkEventExpose *event)
+{
+	static GdkImage *image = NULL;
+
+	if (framebuffer_allocated == FALSE) {
+
+		rfbClientSetClientData (cl, gtk_init, widget);
+
+		image = gdk_drawable_get_image (widget->window, 0, 0,
+		                                widget->allocation.width,
+		                                widget->allocation.height);
+
+		cl->frameBuffer= image->mem;
+
+		cl->width  = widget->allocation.width;
+		cl->height = widget->allocation.height;
+
+		cl->format.bitsPerPixel = image->bits_per_pixel;
+		cl->format.redShift     = image->visual->red_shift;
+		cl->format.greenShift   = image->visual->green_shift;
+		cl->format.blueShift    = image->visual->blue_shift;
+
+		cl->format.redMax   = (1 << image->visual->red_prec) - 1;
+		cl->format.greenMax = (1 << image->visual->green_prec) - 1;
+		cl->format.blueMax  = (1 << image->visual->blue_prec) - 1;
+
+		SetFormatAndEncodings (cl);
+
+		framebuffer_allocated = TRUE;
+	}
+
+	gdk_draw_image (GDK_DRAWABLE (widget->window),
+	                widget->style->fg_gc[gtk_widget_get_state(widget)],
+	                image,
+	                event->area.x, event->area.y,
+	                event->area.x, event->area.y,
+	                event->area.width, event->area.height);
+
+	return FALSE;
+}
+
+struct { int gdk; int rfb; } buttonMapping[] = {
+	{ GDK_BUTTON1_MASK, rfbButton1Mask },
+	{ GDK_BUTTON2_MASK, rfbButton2Mask },
+	{ GDK_BUTTON3_MASK, rfbButton3Mask },
+	{ 0, 0 }
+};
+
+static gboolean button_event (GtkWidget      *widget,
+                              GdkEventButton *event)
+{
+	int x, y;
+	GdkModifierType state;
+	int i, buttonMask;
+
+	gdk_window_get_pointer (event->window, &x, &y, &state);
+
+	for (buttonMask = 0, i = 0; buttonMapping[i].gdk; i++)
+		if (state & buttonMapping[i].gdk)
+			buttonMask |= buttonMapping[i].rfb;
+	SendPointerEvent (cl, x, y, buttonMask);
+
+	return TRUE;
+}
+
+static gboolean motion_notify_event (GtkWidget *widget,
+                                     GdkEventMotion *event)
+{
+	int x, y;
+	GdkModifierType state;
+	int i, buttonMask;
+
+	if (event->is_hint)
+		gdk_window_get_pointer (event->window, &x, &y, &state);
+	else {
+		x = event->x;
+		y = event->y;
+		state = event->state;
+	}
+
+	for (buttonMask = 0, i = 0; buttonMapping[i].gdk; i++)
+		if (state & buttonMapping[i].gdk)
+			buttonMask |= buttonMapping[i].rfb;
+	SendPointerEvent (cl, x, y, buttonMask);
+
+	return TRUE;
+}
+
+static void got_cut_text (rfbClient *cl, const char *text, int textlen)
+{
+	if (server_cut_text != NULL) {
+		g_free (server_cut_text);
+		server_cut_text = NULL;
+	}
+
+	server_cut_text = g_strdup (text);
+}
+
+void received_text_from_clipboard (GtkClipboard *clipboard,
+                                   const gchar *text,
+                                   gpointer data)
+{
+	if (text)
+		SendClientCutText (cl, (char *) text, strlen (text));
+}
+
+static void clipboard_local_to_remote (GtkMenuItem *menuitem,
+                                       gpointer     user_data)
+{
+	GtkClipboard *clipboard;
+
+	clipboard = gtk_widget_get_clipboard (GTK_WIDGET (menuitem),
+	                                      GDK_SELECTION_CLIPBOARD);
+	gtk_clipboard_request_text (clipboard, received_text_from_clipboard,
+	                            NULL);
+}
+
+static void clipboard_remote_to_local (GtkMenuItem *menuitem,
+                                       gpointer     user_data)
+{
+	GtkClipboard *clipboard;
+
+	clipboard = gtk_widget_get_clipboard (GTK_WIDGET (menuitem),
+	                                      GDK_SELECTION_CLIPBOARD);
+
+	gtk_clipboard_set_text (clipboard, server_cut_text,
+	                        strlen (server_cut_text));
+}
+
+static void request_screen_refresh (GtkMenuItem *menuitem,
+                                    gpointer     user_data)
+{
+	SendFramebufferUpdateRequest (cl, 0, 0, cl->width, cl->height, FALSE);
+}
+
+static void send_f8 (GtkMenuItem *menuitem,
+                     gpointer     user_data)
+{
+	SendKeyEvent(cl, XK_F8, TRUE);
+	SendKeyEvent(cl, XK_F8, FALSE);
+}
+
+static void send_crtl_alt_del (GtkMenuItem *menuitem,
+                               gpointer     user_data)
+{
+	SendKeyEvent(cl, XK_Control_L, TRUE);
+	SendKeyEvent(cl, XK_Alt_L, TRUE);
+	SendKeyEvent(cl, XK_Delete, TRUE);
+	SendKeyEvent(cl, XK_Alt_L, FALSE);
+	SendKeyEvent(cl, XK_Control_L, FALSE);
+	SendKeyEvent(cl, XK_Delete, FALSE);
+}
+
+GtkWidget *dialog_connecting = NULL;
+
+static void show_connect_window(int argc, char **argv)
+{
+	GtkWidget *label;
+	char buf[256];
+
+	dialog_connecting = gtk_dialog_new_with_buttons ("VNC Viewer",
+	                                       NULL,
+	                                       GTK_DIALOG_DESTROY_WITH_PARENT,
+	                                       /*GTK_STOCK_CANCEL,
+	                                       GTK_RESPONSE_CANCEL,*/
+	                                       NULL);
+
+	/* FIXME: this works only when address[:port] is at end of arg list */
+	char *server;
+	if(argc==1)
+	    server = "localhost";
+	else
+	   server = argv[argc-1];
+	snprintf(buf, 255, "Connecting to %s...", server);
+
+	label = gtk_label_new (buf);
+	gtk_widget_show (label);
+
+	gtk_container_add (GTK_CONTAINER (GTK_DIALOG(dialog_connecting)->vbox),
+	                   label);
+
+	gtk_widget_show (dialog_connecting);
+
+	while (gtk_events_pending ())
+		gtk_main_iteration ();
+}
+
+static void show_popup_menu()
+{
+	GtkWidget *popup_menu;
+	GtkWidget *menu_item;
+
+	popup_menu = gtk_menu_new ();
+
+	menu_item = gtk_menu_item_new_with_label ("Dismiss popup");
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	menu_item = gtk_menu_item_new_with_label ("Clipboard: local -> remote");
+	g_signal_connect (G_OBJECT (menu_item), "activate",
+	                  G_CALLBACK (clipboard_local_to_remote), NULL);
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	menu_item = gtk_menu_item_new_with_label ("Clipboard: local <- remote");
+	g_signal_connect (G_OBJECT (menu_item), "activate",
+	                  G_CALLBACK (clipboard_remote_to_local), NULL);
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	menu_item = gtk_menu_item_new_with_label ("Request refresh");
+	g_signal_connect (G_OBJECT (menu_item), "activate",
+	                  G_CALLBACK (request_screen_refresh), NULL);
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	menu_item = gtk_menu_item_new_with_label ("Send ctrl-alt-del");
+	g_signal_connect (G_OBJECT (menu_item), "activate",
+	                  G_CALLBACK (send_crtl_alt_del), NULL);
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	menu_item = gtk_menu_item_new_with_label ("Send F8");
+	g_signal_connect (G_OBJECT (menu_item), "activate",
+	                  G_CALLBACK (send_f8), NULL);
+	gtk_widget_show (menu_item);
+	gtk_menu_shell_append (GTK_MENU_SHELL (popup_menu), menu_item);
+
+	gtk_menu_popup (GTK_MENU (popup_menu), NULL, NULL, NULL, NULL, 0,
+	                gtk_get_current_event_time());
+}
+
+static rfbKeySym gdkKey2rfbKeySym(guint keyval)
+{
+	rfbKeySym k = 0;
+	switch(keyval) {
+	case GDK_BackSpace: k = XK_BackSpace; break;
+	case GDK_Tab: k = XK_Tab; break;
+	case GDK_Clear: k = XK_Clear; break;
+	case GDK_Return: k = XK_Return; break;
+	case GDK_Pause: k = XK_Pause; break;
+	case GDK_Escape: k = XK_Escape; break;
+	case GDK_space: k = XK_space; break;
+	case GDK_Delete: k = XK_Delete; break;
+	case GDK_KP_0: k = XK_KP_0; break;
+	case GDK_KP_1: k = XK_KP_1; break;
+	case GDK_KP_2: k = XK_KP_2; break;
+	case GDK_KP_3: k = XK_KP_3; break;
+	case GDK_KP_4: k = XK_KP_4; break;
+	case GDK_KP_5: k = XK_KP_5; break;
+	case GDK_KP_6: k = XK_KP_6; break;
+	case GDK_KP_7: k = XK_KP_7; break;
+	case GDK_KP_8: k = XK_KP_8; break;
+	case GDK_KP_9: k = XK_KP_9; break;
+	case GDK_KP_Decimal: k = XK_KP_Decimal; break;
+	case GDK_KP_Divide: k = XK_KP_Divide; break;
+	case GDK_KP_Multiply: k = XK_KP_Multiply; break;
+	case GDK_KP_Subtract: k = XK_KP_Subtract; break;
+	case GDK_KP_Add: k = XK_KP_Add; break;
+	case GDK_KP_Enter: k = XK_KP_Enter; break;
+	case GDK_KP_Equal: k = XK_KP_Equal; break;
+	case GDK_Up: k = XK_Up; break;
+	case GDK_Down: k = XK_Down; break;
+	case GDK_Right: k = XK_Right; break;
+	case GDK_Left: k = XK_Left; break;
+	case GDK_Insert: k = XK_Insert; break;
+	case GDK_Home: k = XK_Home; break;
+	case GDK_End: k = XK_End; break;
+	case GDK_Page_Up: k = XK_Page_Up; break;
+	case GDK_Page_Down: k = XK_Page_Down; break;
+	case GDK_F1: k = XK_F1; break;
+	case GDK_F2: k = XK_F2; break;
+	case GDK_F3: k = XK_F3; break;
+	case GDK_F4: k = XK_F4; break;
+	case GDK_F5: k = XK_F5; break;
+	case GDK_F6: k = XK_F6; break;
+	case GDK_F7: k = XK_F7; break;
+	case GDK_F8: k = XK_F8; break;
+	case GDK_F9: k = XK_F9; break;
+	case GDK_F10: k = XK_F10; break;
+	case GDK_F11: k = XK_F11; break;
+	case GDK_F12: k = XK_F12; break;
+	case GDK_F13: k = XK_F13; break;
+	case GDK_F14: k = XK_F14; break;
+	case GDK_F15: k = XK_F15; break;
+	case GDK_Num_Lock: k = XK_Num_Lock; break;
+	case GDK_Caps_Lock: k = XK_Caps_Lock; break;
+	case GDK_Scroll_Lock: k = XK_Scroll_Lock; break;
+	case GDK_Shift_R: k = XK_Shift_R; break;
+	case GDK_Shift_L: k = XK_Shift_L; break;
+	case GDK_Control_R: k = XK_Control_R; break;
+	case GDK_Control_L: k = XK_Control_L; break;
+	case GDK_Alt_R: k = XK_Alt_R; break;
+	case GDK_Alt_L: k = XK_Alt_L; break;
+	case GDK_Meta_R: k = XK_Meta_R; break;
+	case GDK_Meta_L: k = XK_Meta_L; break;
+#if 0
+	/* TODO: find out keysyms */
+	case GDK_Super_L: k = XK_LSuper; break;      /* left "windows" key */
+	case GDK_Super_R: k = XK_RSuper; break;      /* right "windows" key */
+	case GDK_Multi_key: k = XK_Compose; break;
+#endif
+	case GDK_Mode_switch: k = XK_Mode_switch; break;
+	case GDK_Help: k = XK_Help; break;
+	case GDK_Print: k = XK_Print; break;
+	case GDK_Sys_Req: k = XK_Sys_Req; break;
+	case GDK_Break: k = XK_Break; break;
+	default: break;
+	}
+	if (k == 0) {
+		if (keyval < 0x100)
+			k = keyval;
+		else
+			rfbClientLog ("Unknown keysym: %d\n", keyval);
+	}
+
+	return k;
+}
+
+static gboolean key_event (GtkWidget *widget, GdkEventKey *event,
+                                 gpointer user_data)
+{
+	if ((event->type == GDK_KEY_PRESS) && (event->keyval == GDK_F8))
+		show_popup_menu();
+	else
+		SendKeyEvent(cl, gdkKey2rfbKeySym (event->keyval),
+		             (event->type == GDK_KEY_PRESS) ? TRUE : FALSE);
+	return FALSE;
+}
+
+void quit ()
+{
+	exit (0);
+}
+
+static rfbBool resize (rfbClient *client) {
+	GtkWidget *window;
+	GtkWidget *scrolled_window;
+	GtkWidget *drawing_area=NULL;
+	static char first=TRUE;
+	int tmp_width, tmp_height;
+
+	if (first) {
+		first=FALSE;
+
+		/* Create the drawing area */
+
+		drawing_area = gtk_drawing_area_new ();
+		gtk_widget_set_size_request (GTK_WIDGET (drawing_area),
+		                             client->width, client->height);
+
+		/* Signals used to handle backing pixmap */
+
+		g_signal_connect (G_OBJECT (drawing_area), "expose_event",
+		                  G_CALLBACK (expose_event), NULL);
+
+		/* Event signals */
+
+		g_signal_connect (G_OBJECT (drawing_area),
+		                  "motion-notify-event",
+		                  G_CALLBACK (motion_notify_event), NULL);
+		g_signal_connect (G_OBJECT (drawing_area),
+		                  "button-press-event",
+		                  G_CALLBACK (button_event), NULL);
+		g_signal_connect (G_OBJECT (drawing_area),
+		                  "button-release-event",
+		                  G_CALLBACK (button_event), NULL);
+
+		gtk_widget_set_events (drawing_area, GDK_EXPOSURE_MASK
+		                       | GDK_LEAVE_NOTIFY_MASK
+		                       | GDK_BUTTON_PRESS_MASK
+		                       | GDK_BUTTON_RELEASE_MASK
+		                       | GDK_POINTER_MOTION_MASK
+		                       | GDK_POINTER_MOTION_HINT_MASK);
+
+		gtk_widget_show (drawing_area);
+
+		scrolled_window = gtk_scrolled_window_new (NULL, NULL);
+		gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
+		                                GTK_POLICY_AUTOMATIC,
+		                                GTK_POLICY_AUTOMATIC);
+		gtk_scrolled_window_add_with_viewport (
+		                  GTK_SCROLLED_WINDOW (scrolled_window),
+		                  drawing_area);
+		g_signal_connect (G_OBJECT (scrolled_window),
+		                  "key-press-event", G_CALLBACK (key_event),
+		                  NULL);
+		g_signal_connect (G_OBJECT (scrolled_window),
+		                  "key-release-event", G_CALLBACK (key_event),
+		                  NULL);
+		gtk_widget_show (scrolled_window);
+
+		window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+		gtk_window_set_title (GTK_WINDOW (window), client->desktopName);
+		gtk_container_add (GTK_CONTAINER (window), scrolled_window);
+		tmp_width = (int) (
+		            gdk_screen_get_width (gdk_screen_get_default ())
+		            * 0.85);
+		if (client->width > tmp_width) {
+			tmp_height = (int) (
+			             gdk_screen_get_height (
+			                     gdk_screen_get_default ())
+			             * 0.85);
+			gtk_widget_set_size_request (window,
+			                             tmp_width, tmp_height);
+		} else {
+			gtk_widget_set_size_request (window,
+			       client->width + 2,
+			       client->height + 2);
+		}
+
+		g_signal_connect (G_OBJECT (window), "destroy",
+		                  G_CALLBACK (quit), NULL);
+
+		gtk_widget_show (window);
+	} else {
+		gtk_widget_set_size_request (GTK_WIDGET (drawing_area),
+		                             client->width, client->height);
+	}
+
+	return TRUE;
+}
+
+static void update (rfbClient *cl, int x, int y, int w, int h) {
+	GtkWidget *drawing_area = rfbClientGetClientData (cl, gtk_init);
+
+	if (drawing_area != NULL)
+		gtk_widget_queue_draw_area (drawing_area, x, y, w, h);
+}
+
+static void kbd_leds (rfbClient *cl, int value, int pad) {
+        /* note: pad is for future expansion 0=unused */
+        fprintf (stderr, "Led State= 0x%02X\n", value);
+        fflush (stderr);
+}
+
+/* trivial support for textchat */
+static void text_chat (rfbClient *cl, int value, char *text) {
+        switch (value) {
+        case rfbTextChatOpen:
+                fprintf (stderr, "TextChat: We should open a textchat window!\n");
+                TextChatOpen (cl);
+                break;
+        case rfbTextChatClose:
+                fprintf (stderr, "TextChat: We should close our window!\n");
+                break;
+        case rfbTextChatFinished:
+                fprintf (stderr, "TextChat: We should close our window!\n");
+                break;
+        default:
+                fprintf (stderr, "TextChat: Received \"%s\"\n", text);
+                break;
+        }
+        fflush (stderr);
+}
+
+static gboolean on_entry_key_press_event (GtkWidget *widget, GdkEventKey *event,
+                                          gpointer user_data)
+{
+	if (event->keyval == GDK_Escape)
+		gtk_dialog_response (GTK_DIALOG(user_data), GTK_RESPONSE_REJECT);
+	else if (event->keyval == GDK_Return)
+		gtk_dialog_response (GTK_DIALOG(user_data), GTK_RESPONSE_ACCEPT);
+
+	return FALSE;
+}
+
+static void GtkErrorLog (const char *format, ...)
+{
+	GtkWidget *dialog, *label;
+	va_list args;
+	char buf[256];
+
+	if (dialog_connecting != NULL) {
+		gtk_widget_destroy (dialog_connecting);
+		dialog_connecting = NULL;
+	}
+
+	va_start (args, format);
+	vsnprintf (buf, 255, format, args);
+	va_end (args);
+
+	if (g_utf8_validate (buf, strlen (buf), NULL)) {
+		label = gtk_label_new (buf);
+	} else {
+		const gchar *charset;
+		gchar       *utf8;
+
+		(void) g_get_charset (&charset);
+		utf8 = g_convert_with_fallback (buf, strlen (buf), "UTF-8",
+		                                charset, NULL, NULL, NULL, NULL);
+
+		if (utf8) {
+			label = gtk_label_new (utf8);
+			g_free (utf8);
+		} else {
+			label = gtk_label_new (buf);
+			g_warning ("Message Output is not in UTF-8"
+			           "nor in locale charset.\n");
+		}
+	}
+
+	dialog = gtk_dialog_new_with_buttons ("Error",
+	                                       NULL,
+	                                       GTK_DIALOG_DESTROY_WITH_PARENT,
+	                                       GTK_STOCK_OK,
+	                                       GTK_RESPONSE_ACCEPT,
+	                                       NULL);
+	label = gtk_label_new (buf);
+	gtk_widget_show (label);
+
+	gtk_container_add (GTK_CONTAINER (GTK_DIALOG(dialog)->vbox),
+	                   label);
+	gtk_widget_show (dialog);
+
+	switch (gtk_dialog_run (GTK_DIALOG (dialog))) {
+	case GTK_RESPONSE_ACCEPT:
+		break;
+	default:
+		break;
+	}
+	gtk_widget_destroy (dialog);
+}
+
+static void GtkDefaultLog (const char *format, ...)
+{
+	va_list args;
+	char buf[256];
+	time_t log_clock;
+
+	va_start (args, format);
+
+	time (&log_clock);
+	strftime (buf, 255, "%d/%m/%Y %X ", localtime (&log_clock));
+	fprintf (stdout, buf);
+
+	vfprintf (stdout, format, args);
+	fflush (stdout);
+
+	va_end (args);
+}
+
+static char * get_password (rfbClient *client)
+{
+	GtkWidget *dialog, *entry;
+	char *password;
+
+	gtk_widget_destroy (dialog_connecting);
+	dialog_connecting = NULL;
+
+	dialog = gtk_dialog_new_with_buttons ("Password",
+	                                       NULL,
+	                                       GTK_DIALOG_DESTROY_WITH_PARENT,
+	                                       GTK_STOCK_CANCEL,
+	                                       GTK_RESPONSE_REJECT,
+	                                       GTK_STOCK_OK,
+	                                       GTK_RESPONSE_ACCEPT,
+	                                       NULL);
+	entry = gtk_entry_new ();
+	gtk_entry_set_visibility (GTK_ENTRY (entry),
+	                          FALSE);
+	g_signal_connect (GTK_OBJECT(entry), "key-press-event",
+	                    G_CALLBACK(on_entry_key_press_event),
+	                    GTK_OBJECT (dialog));
+	gtk_widget_show (entry);
+
+	gtk_container_add (GTK_CONTAINER (GTK_DIALOG(dialog)->vbox),
+	                   entry);
+	gtk_widget_show (dialog);
+
+	switch (gtk_dialog_run (GTK_DIALOG (dialog))) {
+	case GTK_RESPONSE_ACCEPT:
+		password = strdup (gtk_entry_get_text (GTK_ENTRY (entry)));
+		break;
+	default:
+		password = NULL;
+		break;
+	}
+	gtk_widget_destroy (dialog);
+	return password;
+}
+
+int main (int argc, char *argv[])
+{
+	int i;
+	GdkImage *image;
+
+	rfbClientLog = GtkDefaultLog;
+	rfbClientErr = GtkErrorLog;
+
+	gtk_init (&argc, &argv);
+
+	/* create a dummy image just to make use of its properties */
+	image = gdk_image_new (GDK_IMAGE_FASTEST, gdk_visual_get_system(),
+				200, 100);
+
+	cl = rfbGetClient (image->depth / 3, 3, image->bpp);
+
+	cl->format.redShift     = image->visual->red_shift;
+	cl->format.greenShift   = image->visual->green_shift;
+	cl->format.blueShift    = image->visual->blue_shift;
+
+	cl->format.redMax   = (1 << image->visual->red_prec) - 1;
+	cl->format.greenMax = (1 << image->visual->green_prec) - 1;
+	cl->format.blueMax  = (1 << image->visual->blue_prec) - 1;
+
+	g_object_unref (image);
+
+	cl->MallocFrameBuffer = resize;
+	cl->canHandleNewFBSize = TRUE;
+	cl->GotFrameBufferUpdate = update;
+	cl->GotXCutText = got_cut_text;
+	cl->HandleKeyboardLedState = kbd_leds;
+	cl->HandleTextChat = text_chat;
+	cl->GetPassword = get_password;
+
+	show_connect_window (argc, argv);
+
+	if (!rfbInitClient (cl, &argc, argv))
+		return 1;
+
+	while (1) {
+		while (gtk_events_pending ())
+			gtk_main_iteration ();
+		i = WaitForMessage (cl, 500);
+		if (i < 0)
+			return 0;
+		if (i && framebuffer_allocated == TRUE)
+			if (!HandleRFBServerMessage(cl))
+				return 0;
+	}
+
+	gtk_main ();
+
+	return 0;
+}
+
diff --git a/configure.ac b/configure.ac
index 31aa1f2..c5578fa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -740,6 +740,10 @@ AC_SUBST(SDL_CFLAGS)
 AC_SUBST(SDL_LIBS)
 
 
+# Check for GTK+. if present, build the GTK+ vnc viewer example
+PKG_CHECK_MODULES([GTK], [gtk+-2.0])
+AM_CONDITIONAL(HAVE_LIBGTK, test ! -z "$GTK_LIBS")
+
 AC_CANONICAL_HOST
 MINGW=`echo $host_os | grep mingw32  2>/dev/null`
 AM_CONDITIONAL(MINGW, test ! -z "$MINGW" )