path: root/widgets/misc/gal-combo-box.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * gtk-combo-box.c - a customizable combobox
 * Copyright 2000, 2001, Ximian, Inc.
 *
 * Authors:
 *   Miguel de Icaza (miguel@gnu.org)
 *   Adrian E Feiguin (feiguin@ifir.edu.ar)
 *   Paolo Molnaro (lupus@debian.org).
 *   Jon K Hellan (hellan@acm.org)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License, version 2, as published by the Free Software Foundation.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <config.h>
#include <gtk/gtkhbox.h>
#include <gtk/gtktogglebutton.h>
#include <gtk/gtkarrow.h>
#include <gtk/gtkeventbox.h>
#include <gtk/gtkmain.h>
#include <gtk/gtksignal.h>
#include <gtk/gtkwindow.h>
#include <gtk/gtkframe.h>
#include <gtk/gtkvbox.h>
#include <gtk/gtktearoffmenuitem.h>
#include <gdk/gdkkeysyms.h>
#include "gal-combo-box.h"
#include "gal/util/e-util.h"

#define PARENT_TYPE GTK_TYPE_HBOX
static GObjectClass *gal_combo_box_parent_class;

static int gtk_combo_toggle_pressed (GtkToggleButton *tbutton,
                     GalComboBox *combo_box);
static void gtk_combo_popup_tear_off (GalComboBox *combo,
                      gboolean set_position);
static void gtk_combo_set_tearoff_state (GalComboBox *combo,
                     gboolean torn_off);
static void gtk_combo_popup_reparent (GtkWidget *popup, GtkWidget *new_parent, 
                      gboolean unrealize);
static gboolean cb_popup_delete (GtkWidget *w, GdkEventAny *event,
                 GalComboBox *combo);
static void gtk_combo_tearoff_bg_copy (GalComboBox *combo);

enum {
    POP_DOWN_WIDGET,
    POP_DOWN_DONE,
    PRE_POP_DOWN,
    POST_POP_HIDE,
    LAST_SIGNAL
};

static guint gal_combo_box_signals [LAST_SIGNAL] = { 0, };

struct _GalComboBoxPrivate {
    GtkWidget *pop_down_widget;
    GtkWidget *display_widget;

    /*
     * Internal widgets used to implement the ComboBox
     */
    GtkWidget *frame;
    GtkWidget *arrow_button;

    GtkWidget *toplevel;    /* Popup's toplevel when not torn off */
    GtkWidget *tearoff_window; /* Popup's toplevel when torn off */
    guint torn_off;
    
    GtkWidget *tearable;    /* The tearoff "button" */
    GtkWidget *popup;   /* Popup */

    /*
     * Closure for invoking the callbacks above
     */
    void *closure;
};

static void
gal_combo_box_finalize (GObject *object)
{
    GalComboBox *combo_box = GAL_COMBO_BOX (object);

    g_free (combo_box->priv);

    gal_combo_box_parent_class->finalize (object);
}

static void
gal_combo_box_destroy (GtkObject *object)
{
    GtkObjectClass *klass = (GtkObjectClass *)gal_combo_box_parent_class;
    GalComboBox *combo_box = GAL_COMBO_BOX (object);

    if (combo_box->priv->toplevel) {
        gtk_object_destroy (GTK_OBJECT (combo_box->priv->toplevel));
        combo_box->priv->toplevel = NULL;
    }

    if (combo_box->priv->tearoff_window) {
        gtk_object_destroy (GTK_OBJECT (combo_box->priv->tearoff_window));
        combo_box->priv->tearoff_window = NULL;
    }

    if (klass->destroy)
                klass->destroy (object);
}

static gboolean
gal_combo_box_mnemonic_activate (GtkWidget *w, gboolean group_cycling)
{
    GalComboBox *combo_box = GAL_COMBO_BOX (w);
    gtk_toggle_button_set_active (
        GTK_TOGGLE_BUTTON (combo_box->priv->arrow_button), TRUE);
    return TRUE;
}

static void
gal_combo_box_class_init (GObjectClass *object_class)
{
    GtkWidgetClass *widget_class = (GtkWidgetClass *)object_class;
    gal_combo_box_parent_class = g_type_class_peek_parent (object_class);

    object_class->finalize = gal_combo_box_finalize;
    widget_class->mnemonic_activate = gal_combo_box_mnemonic_activate;
    ((GtkObjectClass *)object_class)->destroy = gal_combo_box_destroy;

    gal_combo_box_signals [POP_DOWN_WIDGET] = g_signal_new (
        "pop_down_widget",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GalComboBoxClass, pop_down_widget),
        NULL, NULL,
        e_marshal_POINTER__NONE,
        G_TYPE_POINTER, 0, G_TYPE_NONE);

    gal_combo_box_signals [POP_DOWN_DONE] = g_signal_new (
        "pop_down_done",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GalComboBoxClass, pop_down_done),
        NULL, NULL,
        e_marshal_BOOLEAN__OBJECT,
        G_TYPE_BOOLEAN, 1, G_TYPE_OBJECT);

    gal_combo_box_signals [PRE_POP_DOWN] = g_signal_new (
        "pre_pop_down",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GalComboBoxClass, pre_pop_down),
        NULL, NULL,
        e_marshal_NONE__NONE,
        G_TYPE_NONE, 0);

    gal_combo_box_signals [POST_POP_HIDE] = g_signal_new (
        "post_pop_hide",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GalComboBoxClass, post_pop_hide),
        NULL, NULL,
        e_marshal_NONE__NONE,
        G_TYPE_NONE, 0);
}

static void
deactivate_arrow (GalComboBox *combo_box)
{
    GtkToggleButton *arrow;

    arrow = GTK_TOGGLE_BUTTON (combo_box->priv->arrow_button);
    g_signal_handlers_block_matched (arrow,
                     G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
                     0, 0, NULL,
                     gtk_combo_toggle_pressed, combo_box);

    gtk_toggle_button_set_active (arrow, FALSE);
    
        g_signal_handlers_unblock_matched (arrow,
                       G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
                       0, 0, NULL,
                       gtk_combo_toggle_pressed, combo_box);
}

/**
 * gal_combo_box_popup_hide_unconditional
 * @combo_box:  Combo box
 *
 * Hide popup, whether or not it is torn off.
 */
static void
gal_combo_box_popup_hide_unconditional (GalComboBox *combo_box)
{
    gboolean popup_info_destroyed = FALSE;

    g_return_if_fail (combo_box != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo_box));

    gtk_widget_hide (combo_box->priv->toplevel);
    gtk_widget_hide (combo_box->priv->popup);
    if (combo_box->priv->torn_off) {
        GTK_TEAROFF_MENU_ITEM (combo_box->priv->tearable)->torn_off
            = FALSE;
        gtk_combo_set_tearoff_state (combo_box, FALSE);
    }
    
    gtk_grab_remove (combo_box->priv->toplevel);
    gdk_pointer_ungrab (GDK_CURRENT_TIME);
        
    g_object_ref (combo_box->priv->pop_down_widget);
    g_signal_emit (combo_box,
               gal_combo_box_signals [POP_DOWN_DONE], 0,
               combo_box->priv->pop_down_widget, &popup_info_destroyed);

    if (popup_info_destroyed){
        gtk_container_remove (
            GTK_CONTAINER (combo_box->priv->frame),
            combo_box->priv->pop_down_widget);
        combo_box->priv->pop_down_widget = NULL;
    }
    g_object_unref (combo_box->priv->pop_down_widget);
    deactivate_arrow (combo_box);

    g_signal_emit (combo_box, gal_combo_box_signals [POST_POP_HIDE], 0);
}

/**
 * gal_combo_box_popup_hide:
 * @combo_box:  Combo box
 *
 * Hide popup, but not when it is torn off.
 * This is the external interface - for subclasses and apps which expect a
 * regular combo which doesn't do tearoffs.
 */
void
gal_combo_box_popup_hide (GalComboBox *combo_box)
{
    if (!combo_box->priv->torn_off)
        gal_combo_box_popup_hide_unconditional (combo_box);
    else if (GTK_WIDGET_VISIBLE (combo_box->priv->toplevel)) {
        /* Both popup and tearoff window present. Get rid of just
                   the popup shell. */
        gtk_combo_popup_tear_off (combo_box, FALSE);
        deactivate_arrow (combo_box);
    }        
}

/*
 * Find best location for displaying
 */
void
gal_combo_box_get_pos (GalComboBox *combo_box, int *x, int *y)
{
    GtkWidget *wcombo = GTK_WIDGET (combo_box);
    int ph, pw;

    gdk_window_get_origin (wcombo->window, x, y);
    *y += wcombo->allocation.height + wcombo->allocation.y;
    *x += wcombo->allocation.x;

    ph = combo_box->priv->popup->allocation.height;
    pw = combo_box->priv->popup->allocation.width;

    if ((*y + ph) > gdk_screen_height ())
        *y = gdk_screen_height () - ph;

    if ((*x + pw) > gdk_screen_width ())
        *x = gdk_screen_width () - pw;
}

static void
gal_combo_box_popup_display (GalComboBox *combo_box)
{
    int x, y;

    g_return_if_fail (combo_box != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo_box));
    
    /*
     * If we have no widget to display on the popdown,
     * create it
     */
    if (!combo_box->priv->pop_down_widget){
        GtkWidget *pw = NULL;

        g_signal_emit (combo_box,
                   gal_combo_box_signals [POP_DOWN_WIDGET], 0, &pw);
        g_assert (pw != NULL);
        combo_box->priv->pop_down_widget = pw;
        gtk_container_add (GTK_CONTAINER (combo_box->priv->frame), pw);
    }

    g_signal_emit (combo_box, gal_combo_box_signals [PRE_POP_DOWN], 0);
    
    if (combo_box->priv->torn_off) {
        /* To give the illusion that tearoff still displays the
         * popup, we copy the image in the popup window to the
         * background. Thus, it won't be blank after reparenting */
        gtk_combo_tearoff_bg_copy (combo_box);

        /* We force an unrealize here so that we don't trigger
         * redrawing/ clearing code - we just want to reveal our
         * backing pixmap.
         */
        gtk_combo_popup_reparent (combo_box->priv->popup,
                      combo_box->priv->toplevel, TRUE);
    }

    gal_combo_box_get_pos (combo_box, &x, &y);
    
    gtk_widget_set_uposition (combo_box->priv->toplevel, x, y);
    gtk_widget_realize (combo_box->priv->popup);
    gtk_widget_show (combo_box->priv->popup);
    gtk_widget_realize (combo_box->priv->toplevel);
    gtk_widget_show (combo_box->priv->toplevel);
    
    gtk_grab_add (combo_box->priv->toplevel);
    gdk_pointer_grab (combo_box->priv->toplevel->window, TRUE,
              GDK_BUTTON_PRESS_MASK |
              GDK_BUTTON_RELEASE_MASK |
              GDK_POINTER_MOTION_MASK,
              NULL, NULL, GDK_CURRENT_TIME);
}

static int
gtk_combo_toggle_pressed (GtkToggleButton *tbutton, GalComboBox *combo_box)
{
    if (tbutton->active)
        gal_combo_box_popup_display (combo_box);
    else
        gal_combo_box_popup_hide_unconditional (combo_box);

    return TRUE;
}

static  gint
gal_combo_box_button_press (GtkWidget *widget, GdkEventButton *event, GalComboBox *combo_box)
{
    GtkWidget *child;

    child = gtk_get_event_widget ((GdkEvent *) event);
    if (child != widget){
        while (child){
            if (child == widget)
                return FALSE;
            child = child->parent;
        }
    }

    gal_combo_box_popup_hide (combo_box);
    return TRUE;
}

/**
 * gal_combo_box_key_press
 * @widget:     Widget
 * @event:      Event
 * @combo_box:  Combo box
 *
 * Key press handler which dismisses popup on escape.
 * Popup is dismissed whether or not popup is torn off.
 */
static  gint
gal_combo_box_key_press (GtkWidget *widget, GdkEventKey *event,
             GalComboBox *combo_box)
{
    if (event->keyval == GDK_Escape) {
        gal_combo_box_popup_hide_unconditional (combo_box);
        return TRUE;
    } else
        return FALSE;
}

static void
cb_state_change (GtkWidget *widget, GtkStateType old_state, GalComboBox *combo_box)
{
    GtkStateType const new_state = GTK_WIDGET_STATE(widget);
    gtk_widget_set_state (combo_box->priv->display_widget, new_state);
}

static void
gal_combo_box_init (GalComboBox *combo_box)
{
    GtkWidget *arrow;
    GdkCursor *cursor;

    combo_box->priv = g_new0 (GalComboBoxPrivate, 1);

    /*
     * Create the arrow
     */
    combo_box->priv->arrow_button = gtk_toggle_button_new ();
    gtk_button_set_relief (GTK_BUTTON (combo_box->priv->arrow_button), GTK_RELIEF_NONE);
    GTK_WIDGET_UNSET_FLAGS (combo_box->priv->arrow_button, GTK_CAN_FOCUS);

    arrow = gtk_arrow_new (GTK_ARROW_DOWN, GTK_SHADOW_NONE);
    gtk_container_add (GTK_CONTAINER (combo_box->priv->arrow_button), arrow);
    gtk_box_pack_end (GTK_BOX (combo_box), combo_box->priv->arrow_button, FALSE, FALSE, 0);
    g_signal_connect (combo_box->priv->arrow_button, "toggled",
              G_CALLBACK (gtk_combo_toggle_pressed), combo_box);
    gtk_widget_show_all (combo_box->priv->arrow_button);

    /*
     * prelight the display widget when mousing over the arrow.
     */
    g_signal_connect (combo_box->priv->arrow_button, "state-changed",
              G_CALLBACK (cb_state_change), combo_box);

    /*
     * The pop-down container
     */

    combo_box->priv->toplevel = gtk_window_new (GTK_WINDOW_POPUP);
    gtk_widget_ref (combo_box->priv->toplevel);
    gtk_object_sink (GTK_OBJECT (combo_box->priv->toplevel));
    gtk_window_set_policy (GTK_WINDOW (combo_box->priv->toplevel),
                   FALSE, TRUE, FALSE);

    combo_box->priv->popup = gtk_event_box_new ();
    gtk_container_add (GTK_CONTAINER (combo_box->priv->toplevel),
               combo_box->priv->popup);
    gtk_widget_show (combo_box->priv->popup);

    gtk_widget_realize (combo_box->priv->popup);
    cursor = gdk_cursor_new (GDK_TOP_LEFT_ARROW);
    gdk_window_set_cursor (combo_box->priv->popup->window, cursor);
    gdk_cursor_destroy (cursor);

    combo_box->priv->torn_off = FALSE;
    combo_box->priv->tearoff_window = NULL;
    
    combo_box->priv->frame = gtk_frame_new (NULL);
    gtk_container_add (GTK_CONTAINER (combo_box->priv->popup),
               combo_box->priv->frame);
    gtk_frame_set_shadow_type (GTK_FRAME (combo_box->priv->frame), GTK_SHADOW_OUT);

    g_signal_connect (combo_box->priv->toplevel, "button_press_event",
              G_CALLBACK (gal_combo_box_button_press), combo_box);
    g_signal_connect (combo_box->priv->toplevel, "key_press_event",
              G_CALLBACK (gal_combo_box_key_press), combo_box);
}

E_MAKE_TYPE (gal_combo_box,
         "MyGalComboBox",
         GalComboBox,
         gal_combo_box_class_init,
         gal_combo_box_init,
         PARENT_TYPE)

/**
 * gal_combo_box_set_display:
 * @combo_box: the Combo Box to modify
 * @display_widget: The widget to be displayed

 * Sets the displayed widget for the @combo_box to be @display_widget
 */
void
gal_combo_box_set_display (GalComboBox *combo_box, GtkWidget *display_widget)
{
    g_return_if_fail (combo_box != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo_box));
    g_return_if_fail (display_widget != NULL);
    g_return_if_fail (GTK_IS_WIDGET (display_widget));

    if (combo_box->priv->display_widget &&
        combo_box->priv->display_widget != display_widget)
        gtk_container_remove (GTK_CONTAINER (combo_box),
                      combo_box->priv->display_widget);

    combo_box->priv->display_widget = display_widget;

    gtk_box_pack_start (GTK_BOX (combo_box), display_widget, TRUE, TRUE, 0);
}

static gboolean
cb_tearable_enter_leave (GtkWidget *w, GdkEventCrossing *event, gpointer data)
{
    gboolean const flag = GPOINTER_TO_INT(data);
    gtk_widget_set_state (w, flag ? GTK_STATE_PRELIGHT : GTK_STATE_NORMAL);
    return FALSE;
}

/**
 * gtk_combo_popup_tear_off
 * @combo:         Combo box
 * @set_position:  Set to position of popup shell if true
 *
 * Tear off the popup
 *
 * FIXME:
 * Gtk popup menus are toplevel windows, not dialogs. I think this is wrong,
 * and make the popups dialogs. But may be there should be a way to make
 * them toplevel. We can do this after creating:
 * GTK_WINDOW (tearoff)->type = GTK_WINDOW_TOPLEVEL;
 */
static void
gtk_combo_popup_tear_off (GalComboBox *combo, gboolean set_position)
{
    int x, y;
    
    if (!combo->priv->tearoff_window) {
        GtkWidget *tearoff;
        gchar *title;
        
        /* FIXME: made this a toplevel, not a dialog ! */
        tearoff = gtk_window_new (GTK_WINDOW_TOPLEVEL);
        gtk_widget_ref (tearoff);
        gtk_object_sink (GTK_OBJECT (tearoff));
        combo->priv->tearoff_window = tearoff;
        gtk_widget_set_app_paintable (tearoff, TRUE);
        g_signal_connect (tearoff, "key_press_event",
                  G_CALLBACK (gal_combo_box_key_press),
                  combo);
        gtk_widget_realize (tearoff);
        title = g_object_get_data (G_OBJECT (combo),
                       "gtk-combo-title");
        if (title)
            gdk_window_set_title (tearoff->window, title);
        gtk_window_set_policy (GTK_WINDOW (tearoff),
                       FALSE, TRUE, FALSE);
        gtk_window_set_transient_for 
            (GTK_WINDOW (tearoff),
             GTK_WINDOW (gtk_widget_get_toplevel
                     GTK_WIDGET (combo)));
    }

    if (GTK_WIDGET_VISIBLE (combo->priv->popup)) {
        gtk_widget_hide (combo->priv->toplevel);
        
        gtk_grab_remove (combo->priv->toplevel);
        gdk_pointer_ungrab (GDK_CURRENT_TIME);
    }

    gtk_combo_popup_reparent (combo->priv->popup,
                  combo->priv->tearoff_window, FALSE);

    /* It may have got confused about size */
    gtk_widget_queue_resize (GTK_WIDGET (combo->priv->popup));

    if (set_position) {
        gal_combo_box_get_pos (combo, &x, &y);
        gtk_widget_set_uposition (combo->priv->tearoff_window, x, y);
    }
    gtk_widget_show (GTK_WIDGET (combo->priv->popup));
    gtk_widget_show (combo->priv->tearoff_window);
        
}

/**
 * gtk_combo_set_tearoff_state
 * @combo_box:  Combo box
 * @torn_off:   TRUE: Tear off. FALSE: Pop down and reattach
 *
 * Set the tearoff state of the popup
 *
 * Compare with gtk_menu_set_tearoff_state in gtk/gtkmenu.c
 */
static void       
gtk_combo_set_tearoff_state (GalComboBox *combo,
                 gboolean  torn_off)
{
    g_return_if_fail (combo != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo));
    
    if (combo->priv->torn_off != torn_off) {
        combo->priv->torn_off = torn_off;
        
        if (combo->priv->torn_off) {
            gtk_combo_popup_tear_off (combo, TRUE);
            deactivate_arrow (combo);
        } else {
            gtk_widget_hide (combo->priv->tearoff_window);
            gtk_combo_popup_reparent (combo->priv->popup,
                          combo->priv->toplevel,
                          FALSE);
        }
    }
}

/**
 * gtk_combo_tearoff_bg_copy
 * @combo_box:  Combo box
 *
 * Copy popup window image to the tearoff window.
 */
static void
gtk_combo_tearoff_bg_copy (GalComboBox *combo)
{
    GdkPixmap *pixmap;
    GdkGC *gc;
    GdkGCValues gc_values;

    GtkWidget *widget = combo->priv->popup;

    if (combo->priv->torn_off) {
        gc_values.subwindow_mode = GDK_INCLUDE_INFERIORS;
        gc = gdk_gc_new_with_values (widget->window,
                         &gc_values, GDK_GC_SUBWINDOW);
      
        pixmap = gdk_pixmap_new (widget->window,
                     widget->allocation.width,
                     widget->allocation.height,
                     -1);

        gdk_draw_pixmap (pixmap, gc,
                 widget->window,
                 0, 0, 0, 0, -1, -1);
        gdk_gc_unref (gc);
      
        gtk_widget_set_usize (combo->priv->tearoff_window,
                      widget->allocation.width,
                      widget->allocation.height);
      
        gdk_window_set_back_pixmap
            (combo->priv->tearoff_window->window, pixmap, FALSE);
        gdk_pixmap_unref (pixmap);
    }
}

/**
 * gtk_combo_popup_reparent
 * @popup:       Popup
 * @new_parent:  New parent
 * @unrealize:   Unrealize popup if TRUE.
 *
 * Reparent the popup, taking care of the refcounting
 *
 * Compare with gtk_menu_reparent in gtk/gtkmenu.c
 */
static void 
gtk_combo_popup_reparent (GtkWidget *popup, 
              GtkWidget *new_parent, 
              gboolean unrealize)
{
    GtkObject *object = GTK_OBJECT (popup);
    gboolean was_floating = GTK_OBJECT_FLOATING (object);

    g_object_ref (object);
    gtk_object_sink (object);

    if (unrealize) {
        g_object_ref (object);
        gtk_container_remove (GTK_CONTAINER (popup->parent), popup);
        gtk_container_add (GTK_CONTAINER (new_parent), popup);
        g_object_unref (object);
    }
    else
        gtk_widget_reparent (GTK_WIDGET (popup), new_parent);
    gtk_widget_set_usize (new_parent, -1, -1);
  
    if (was_floating)
        GTK_OBJECT_SET_FLAGS (object, GTK_FLOATING);
    else
        g_object_unref (object);
}

/**
 * cb_tearable_button_release
 * @w:      Widget
 * @event:  Event
 * @combo:  Combo box
 *
 * Toggle tearoff state.
 */
static gboolean
cb_tearable_button_release (GtkWidget *w, GdkEventButton *event,
                GalComboBox *combo)
{
    GtkTearoffMenuItem *tearable;
    
    g_return_val_if_fail (w != NULL, FALSE);
    g_return_val_if_fail (GTK_IS_TEAROFF_MENU_ITEM (w), FALSE);

    tearable = GTK_TEAROFF_MENU_ITEM (w);
    tearable->torn_off = !tearable->torn_off;

    if (!combo->priv->torn_off) {
        gboolean need_connect;
            
        need_connect = (!combo->priv->tearoff_window);
        gtk_combo_set_tearoff_state (combo, TRUE);
        if (need_connect)
            g_signal_connect (combo->priv->tearoff_window,  
                      "delete_event",
                      G_CALLBACK (cb_popup_delete),
                      combo);
    } else
        gal_combo_box_popup_hide_unconditional (combo);
    
    return TRUE;
}

static gboolean
cb_popup_delete (GtkWidget *w, GdkEventAny *event, GalComboBox *combo)
{
    gal_combo_box_popup_hide_unconditional (combo);
    return TRUE;
}

void
gal_combo_box_construct (GalComboBox *combo_box, GtkWidget *display_widget, GtkWidget *pop_down_widget)
{
    GtkWidget *tearable;
    GtkWidget *vbox;

    g_return_if_fail (combo_box != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo_box));
    g_return_if_fail (display_widget  != NULL);
    g_return_if_fail (GTK_IS_WIDGET (display_widget));

    GTK_BOX (combo_box)->spacing = 0;
    GTK_BOX (combo_box)->homogeneous = FALSE;

    combo_box->priv->pop_down_widget = pop_down_widget;
    combo_box->priv->display_widget = NULL;

    vbox = gtk_vbox_new (FALSE, 5);
    tearable = gtk_tearoff_menu_item_new ();
    g_signal_connect (tearable, "enter-notify-event",
              G_CALLBACK (cb_tearable_enter_leave),
              GINT_TO_POINTER (TRUE));
    g_signal_connect (tearable, "leave-notify-event",
              G_CALLBACK (cb_tearable_enter_leave),
              GINT_TO_POINTER (FALSE));
    g_signal_connect (tearable, "button-release-event",
              G_CALLBACK (cb_tearable_button_release),
              (gpointer) combo_box);
    gtk_box_pack_start (GTK_BOX (vbox), tearable, FALSE, FALSE, 0);
    gtk_box_pack_start (GTK_BOX (vbox), pop_down_widget, TRUE, TRUE, 0);
    combo_box->priv->tearable = tearable;

    /*
     * Finish setup
     */
    gal_combo_box_set_display (combo_box, display_widget);

    gtk_container_add (GTK_CONTAINER (combo_box->priv->frame), vbox);
    gtk_widget_show_all (combo_box->priv->frame);
}

GtkWidget *
gal_combo_box_new (GtkWidget *display_widget, GtkWidget *optional_popdown)
{
    GalComboBox *combo_box;

    g_return_val_if_fail (display_widget  != NULL, NULL);
    g_return_val_if_fail (GTK_IS_WIDGET (display_widget), NULL);

    combo_box = g_object_new (GAL_COMBO_BOX_TYPE, NULL);
    gal_combo_box_construct (combo_box, display_widget, optional_popdown);
    return GTK_WIDGET (combo_box);
}

void
gal_combo_box_set_arrow_relief (GalComboBox *cc, GtkReliefStyle relief)
{
    g_return_if_fail (cc != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (cc));

    gtk_button_set_relief (GTK_BUTTON (cc->priv->arrow_button), relief);
}

/**
 * gal_combo_box_set_title
 * @combo: Combo box
 * @title: Title
 *
 * Set a title to display over the tearoff window.
 *
 * FIXME:
 *
 * This should really change the title even when the popup is already torn off.
 * I guess the tearoff window could attach a listener to title change or
 * something. But I don't think we need the functionality, so I didn't bother
 * to investigate.
 */
void       
gal_combo_box_set_title (GalComboBox *combo,
             const gchar *title)
{
    g_return_if_fail (combo != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo));
    
    g_object_set_data_full (G_OBJECT (combo), "gtk-combo-title",
                g_strdup (title), (GDestroyNotify) g_free);
}

/**
 * gal_combo_box_set_arrow_sensitive
 * @combo:  Combo box
 * @sensitive:  Sensitivity value
 *
 * Toggle the sensitivity of the arrow button
 */

void
gal_combo_box_set_arrow_sensitive (GalComboBox *combo,
                   gboolean sensitive)
{
    g_return_if_fail (combo != NULL);

    gtk_widget_set_sensitive (combo->priv->arrow_button, sensitive);
}

/**
 * gal_combo_box_set_tearable:
 * @combo: Combo box
 * @tearable: whether to allow the @combo to be tearable
 *
 * controls whether the combo box's pop up widget can be torn off.
 */
void
gal_combo_box_set_tearable (GalComboBox *combo, gboolean tearable)
{
    g_return_if_fail (combo != NULL);
    g_return_if_fail (GAL_IS_COMBO_BOX (combo));

    if (tearable){
        gtk_widget_show (combo->priv->tearable);
    } else {
        gtk_combo_set_tearoff_state (combo, FALSE);
        gtk_widget_hide (combo->priv->tearable);
    }
}