about control signal and event.........

[=?big5?b?tsC8eSBLYXNvbiBIdWFuZw==?= <kasonhuang kinposh com cn>]

hi:
i am doing a project.in that i must contrast the mouse clicked signal with key pressed event.
i doing a testing code. like  following:

#include <gtk/gtk.h>


GtkWidget *xpm_label_box( GtkWidget *parent,
                          gchar     *xpm_filename,
                          gchar     *label_text )
{
    GtkWidget *box1;
    GtkWidget *label;
    GtkWidget *pixmapwid;
    GdkPixmap *pixmap;
    GdkBitmap *mask;
    GtkStyle *style;

    box1 = gtk_hbox_new (FALSE, 0);
    gtk_container_set_border_width (GTK_CONTAINER (box1), 2);

    style = gtk_widget_get_style(parent);

    pixmap = gdk_pixmap_create_from_xpm (parent->window, &mask,
					 &style->bg[GTK_STATE_NORMAL],
					 xpm_filename);
    pixmapwid = gtk_pixmap_new (pixmap, mask);

    label = gtk_label_new (label_text);

    gtk_box_pack_start (GTK_BOX (box1),
			pixmapwid, FALSE, FALSE, 3);

    gtk_box_pack_start (GTK_BOX (box1), label, FALSE, FALSE, 3);

    gtk_widget_show(pixmapwid);
    gtk_widget_show(label);

    return(box1);
}

void clickedcallback( GtkWidget *widget, gpointer   data )
{
    g_print ("clicked signal happened\n");
}

void buttonpresscallback( GtkWidget *widget,GdkEvent *event, gpointer data)
{
  g_print ("button_press_event happened\n");
}

void buttonreleasecallback( GtkWidget *widget,GdkEvent *event, gpointer data)
{
  g_print ("button_release_event happened\n");
}

int main( int   argc, char *argv[] )
{
    GtkWidget *window;
    GtkWidget *button;
    GtkWidget *box1;

    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title (GTK_WINDOW (window), "Pixmap'd Buttons!");
    gtk_signal_connect (GTK_OBJECT (window), "destroy",
			GTK_SIGNAL_FUNC (gtk_exit), NULL);
    gtk_signal_connect (GTK_OBJECT (window), "delete_event",
			GTK_SIGNAL_FUNC (gtk_exit), NULL);
    gtk_container_set_border_width (GTK_CONTAINER (window), 10);
    gtk_widget_realize(window);

    /*  the following is the key code i tested, how to call back a function by button_press_event, but not by mouse clicked.
    *   the result is that  mouse clicked will turn to happen button_press_event at same time. how to happen 
    *   clicked signal not happen button_press_event.
   */
    button = gtk_button_new ();
    gtk_signal_connect (GTK_OBJECT (button),"clicked",
		GTK_SIGNAL_FUNC (clickedcallback), (gpointer) "cool button");
    gtk_signal_connect (GTK_OBJECT (button),"button_press_event",
		GTK_SIGNAL_FUNC (buttonpresscallback), NULL);
   gtk_signal_connect (GTK_OBJECT (button),"button_release_event",
		GTK_SIGNAL_FUNC (buttonreleasecallback), NULL);

    box1 = xpm_label_box(window, "info.xpm", "cool button");
    gtk_widget_show(box1);
    gtk_container_add (GTK_CONTAINER (button), box1);
    gtk_widget_show(button);
    gtk_container_add (GTK_CONTAINER (window), button);
    gtk_widget_show (window);

    gtk_main ();
    return(0);
}

my problem is writen in the code by note,maybe i should to trace gdkevent .someone could help me.
thanks a lot!
kason