[eel-canvas] don't use GtkObject (GTK3)

the ::destroy signal of GtkObject has only been moved to GtkWidget in GTK3
(after GtkObject removal): http://developer.gnome.org/gtk3/3.0/ch25s02.html
So, we conditionals in this case, to keep working with GTK2

Nautilus commit message: This implies adding a 'destroy' signal to EelCanvasItem,
with similar semantics to gtk_object_destroy()
http://git.gnome.org/browse/nautilus/commit/?id=1f615321613751a5dbc84d5ef7f20edd104b8dc4

3 files changed, 63 insertions, 57 deletions

diff --git a/eel/eel-canvas-rect-ellipse.c b/eel/eel-canvas-rect-ellipse.c
index 9d738243..18263ce9 100644
--- a/eel/eel-canvas-rect-ellipse.c
+++ b/eel/eel-canvas-rect-ellipse.c
@@ -68,7 +68,6 @@ enum
 
 static void eel_canvas_re_class_init (EelCanvasREClass *klass);
 static void eel_canvas_re_init       (EelCanvasRE      *re);
-static void eel_canvas_re_destroy    (GtkObject          *object);
 static void eel_canvas_re_set_property (GObject              *object,
                                         guint                 param_id,
                                         const GValue         *value,
@@ -133,11 +132,9 @@ static void
 eel_canvas_re_class_init (EelCanvasREClass *klass)
 {
     GObjectClass *gobject_class;
-    GtkObjectClass *object_class;
     EelCanvasItemClass *item_class;
 
     gobject_class = (GObjectClass *) klass;
-    object_class = (GtkObjectClass *) klass;
     item_class = (EelCanvasItemClass *) klass;
 
     re_parent_class = g_type_class_peek_parent (klass);
@@ -223,8 +220,6 @@ eel_canvas_re_class_init (EelCanvasREClass *klass)
                           0.0, G_MAXDOUBLE, 0.0,
                           G_PARAM_READWRITE));
 
-    object_class->destroy = eel_canvas_re_destroy;
-
     item_class->realize = eel_canvas_re_realize;
     item_class->unrealize = eel_canvas_re_unrealize;
     item_class->translate = eel_canvas_re_translate;
@@ -241,22 +236,6 @@ eel_canvas_re_init (EelCanvasRE *re)
     re->width = 0.0;
 }
 
-static void
-eel_canvas_re_destroy (GtkObject *object)
-{
-    EelCanvasRE *re;
-
-    g_return_if_fail (object != NULL);
-    g_return_if_fail (EEL_IS_CANVAS_RE (object));
-
-    re = EEL_CANVAS_RE (object);
-
-    /* remember, destroy can be run multiple times! */
-
-    if (GTK_OBJECT_CLASS (re_parent_class)->destroy)
-        (* GTK_OBJECT_CLASS (re_parent_class)->destroy) (object);
-}
-
 static void get_bounds (EelCanvasRE *re, double *px1, double *py1, double *px2, double *py2)
 {
     EelCanvasItem *item;
diff --git a/eel/eel-canvas.c b/eel/eel-canvas.c
index ff38d197..647de723 100644
--- a/eel/eel-canvas.c
+++ b/eel/eel-canvas.c
@@ -101,6 +101,7 @@ enum
 
 enum
 {
+    ITEM_DESTROY,
     ITEM_EVENT,
     ITEM_LAST_SIGNAL
 };
@@ -111,7 +112,7 @@ static int  emit_event                       (EelCanvas *canvas, GdkEvent *event
 
 static guint item_signals[ITEM_LAST_SIGNAL];
 
-static GtkObjectClass *item_parent_class;
+static GObjectClass *item_parent_class;
 
 static gpointer accessible_item_parent_class;
 static gpointer accessible_parent_class;
@@ -145,10 +146,10 @@ eel_canvas_item_get_type (void)
             (GInstanceInitFunc) eel_canvas_item_init
         };
 
-        canvas_item_type = g_type_register_static (gtk_object_get_type (),
-                           "EelCanvasItem",
-                           &canvas_item_info,
-                           0);
+        canvas_item_type = g_type_register_static (G_TYPE_INITIALLY_UNOWNED,
+        					   "EelCanvasItem",
+        					   &canvas_item_info,
+        					   0);
     }
 
     return canvas_item_type;
@@ -359,9 +360,21 @@ eel_canvas_item_dispose (GObject *object)
         item->canvas = NULL;
     }
 
+    g_object_set_data (object, "in-destruction", GINT_TO_POINTER (1));
+    g_signal_emit (object, item_signals[ITEM_DESTROY], 0);
+
+    g_object_set_data (object, "in-destruction", NULL);
+
     G_OBJECT_CLASS (item_parent_class)->dispose (object);
 }
 
+void
+eel_canvas_item_destroy (EelCanvasItem *item)
+{
+	if (g_object_get_data (G_OBJECT (item), "in-destruction") == NULL) {
+		g_object_run_dispose (G_OBJECT (item));
+	}
+}
 
 /* Realize handler for canvas items */
 static void
@@ -1200,7 +1213,7 @@ static void eel_canvas_group_get_property(GObject               *object,
         GValue                *value,
         GParamSpec            *pspec);
 
-static void eel_canvas_group_destroy     (GtkObject             *object);
+static void eel_canvas_group_destroy     (EelCanvasItem         *object);
 
 static void   eel_canvas_group_update      (EelCanvasItem *item,
         double           i2w_dx,
@@ -1266,11 +1279,9 @@ static void
 eel_canvas_group_class_init (EelCanvasGroupClass *klass)
 {
     GObjectClass *gobject_class;
-    GtkObjectClass *object_class;
     EelCanvasItemClass *item_class;
 
     gobject_class = (GObjectClass *) klass;
-    object_class = (GtkObjectClass *) klass;
     item_class = (EelCanvasItemClass *) klass;
 
     group_parent_class = g_type_class_peek_parent (klass);
@@ -1293,8 +1304,7 @@ eel_canvas_group_class_init (EelCanvasGroupClass *klass)
                           -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
                           G_PARAM_READWRITE));
 
-    object_class->destroy = eel_canvas_group_destroy;
-
+    item_class->destroy = eel_canvas_group_destroy;
     item_class->update = eel_canvas_group_update;
     item_class->unrealize = eel_canvas_group_unrealize;
     item_class->map = eel_canvas_group_map;
@@ -1391,7 +1401,7 @@ eel_canvas_group_get_property (GObject *gobject, guint param_id,
 
 /* Destroy handler for canvas groups */
 static void
-eel_canvas_group_destroy (GtkObject *object)
+eel_canvas_group_destroy (EelCanvasItem *object)
 {
     EelCanvasGroup *group;
     EelCanvasItem *child;
@@ -1407,11 +1417,11 @@ eel_canvas_group_destroy (GtkObject *object)
         child = list->data;
         list = list->next;
 
-        gtk_object_destroy (GTK_OBJECT (child));
+        eel_canvas_item_destroy (child);
     }
 
-    if (GTK_OBJECT_CLASS (group_parent_class)->destroy)
-        (* GTK_OBJECT_CLASS (group_parent_class)->destroy) (object);
+    if (EEL_CANVAS_ITEM_CLASS (group_parent_class)->destroy)
+        (* EEL_CANVAS_ITEM_CLASS (group_parent_class)->destroy) (object);
 }
 
 /* Update handler for canvas groups */
@@ -1720,12 +1730,7 @@ eel_canvas_group_bounds (EelCanvasItem *item, double *x1, double *y1, double *x2
 static void
 group_add (EelCanvasGroup *group, EelCanvasItem *item)
 {
-#if GLIB_CHECK_VERSION(2,10,0) && GTK_CHECK_VERSION(2,8,14)
     g_object_ref_sink (item);
-#else
-    g_object_ref (item);
-    gtk_object_sink (GTK_OBJECT (item));
-#endif
 
     if (!group->item_list)
     {
@@ -1793,7 +1798,11 @@ enum
 
 static void eel_canvas_class_init          (EelCanvasClass *klass);
 static void eel_canvas_init                (EelCanvas      *canvas);
+#if GTK_CHECK_VERSION (3, 0, 0)
+static void eel_canvas_destroy             (GtkWidget        *object);
+#else
 static void eel_canvas_destroy             (GtkObject        *object);
+#endif
 static void eel_canvas_map                 (GtkWidget        *widget);
 static void eel_canvas_unmap               (GtkWidget        *widget);
 static void eel_canvas_realize             (GtkWidget        *widget);
@@ -2108,11 +2117,9 @@ static void
 eel_canvas_class_init (EelCanvasClass *klass)
 {
     GObjectClass   *gobject_class;
-    GtkObjectClass *object_class;
     GtkWidgetClass *widget_class;
 
     gobject_class = (GObjectClass *)klass;
-    object_class  = (GtkObjectClass *) klass;
     widget_class  = (GtkWidgetClass *) klass;
 
     canvas_parent_class = g_type_class_peek_parent (klass);
@@ -2120,8 +2127,11 @@ eel_canvas_class_init (EelCanvasClass *klass)
     gobject_class->set_property = eel_canvas_set_property;
     gobject_class->get_property = eel_canvas_get_property;
 
-    object_class->destroy = eel_canvas_destroy;
-
+#if !GTK_CHECK_VERSION (3, 0, 0)
+    GTK_OBJECT_CLASS (klass)->destroy = eel_canvas_destroy;
+#else
+    widget_class->destroy = eel_canvas_destroy;
+#endif
     widget_class->map = eel_canvas_map;
     widget_class->unmap = eel_canvas_unmap;
     widget_class->realize = eel_canvas_realize;
@@ -2143,7 +2153,7 @@ eel_canvas_class_init (EelCanvasClass *klass)
 
     canvas_signals[DRAW_BACKGROUND] =
         g_signal_new ("draw_background",
-                      G_TYPE_FROM_CLASS (object_class),
+                      G_TYPE_FROM_CLASS (klass),
                       G_SIGNAL_RUN_LAST,
                       G_STRUCT_OFFSET (EelCanvasClass, draw_background),
                       NULL, NULL,
@@ -2160,7 +2170,7 @@ eel_canvas_class_init (EelCanvasClass *klass)
  * never ever do this, so we panic if this happens.
  */
 static void
-panic_root_destroyed (GtkObject *object, gpointer data)
+panic_root_destroyed (GtkWidget *object, gpointer data)
 {
     g_error ("Eeeek, root item %p of canvas %p was destroyed!", object, data);
 }
@@ -2195,12 +2205,7 @@ eel_canvas_init (EelCanvas *canvas)
     canvas->root = EEL_CANVAS_ITEM (g_object_new (eel_canvas_group_get_type (), NULL));
     canvas->root->canvas = canvas;
 
-#if GLIB_CHECK_VERSION(2,10,0) && GTK_CHECK_VERSION(2,8,14)
     g_object_ref_sink (canvas->root);
-#else
-    g_object_ref (canvas->root);
-    gtk_object_sink (GTK_OBJECT (canvas->root));
-#endif
 
     canvas->root_destroy_id = g_signal_connect (G_OBJECT (canvas->root),
                               "destroy", G_CALLBACK (panic_root_destroyed), canvas);
@@ -2246,7 +2251,11 @@ shutdown_transients (EelCanvas *canvas)
 
 /* Destroy handler for EelCanvas */
 static void
+#if GTK_CHECK_VERSION (3, 0, 0)
+eel_canvas_destroy (GtkWidget *object)
+#else
 eel_canvas_destroy (GtkObject *object)
+#endif
 {
     EelCanvas *canvas;
 
@@ -2265,14 +2274,19 @@ eel_canvas_destroy (GtkObject *object)
     {
         EelCanvasItem *root = canvas->root;
         canvas->root = NULL;
-        gtk_object_destroy (GTK_OBJECT (root));
+        eel_canvas_item_destroy (root);
         g_object_unref (root);
     }
 
     shutdown_transients (canvas);
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+    if (GTK_WIDGET_CLASS (canvas_parent_class)->destroy)
+        (* GTK_WIDGET_CLASS (canvas_parent_class)->destroy) (object);
+#else
     if (GTK_OBJECT_CLASS (canvas_parent_class)->destroy)
         (* GTK_OBJECT_CLASS (canvas_parent_class)->destroy) (object);
+#endif
 }
 
 /**
@@ -2673,14 +2687,14 @@ emit_event (EelCanvas *canvas, GdkEvent *event)
 
     while (item && !finished)
     {
-        g_object_ref (GTK_OBJECT (item));
+        g_object_ref (item);
 
         g_signal_emit (
             G_OBJECT (item), item_signals[ITEM_EVENT], 0,
             &ev, &finished);
 
         parent = item->parent;
-        g_object_unref (GTK_OBJECT (item));
+        g_object_unref (item);
 
         item = parent;
     }
@@ -4015,7 +4029,7 @@ eel_canvas_item_accessible_get_type (void)
         GTypeInfo tinfo = { 0 };
 
         factory = atk_registry_get_factory (atk_get_default_registry(),
-                                            GTK_TYPE_OBJECT);
+                                            G_TYPE_INITIALLY_UNOWNED);
         if (!factory)
         {
             return G_TYPE_INVALID;
@@ -4148,6 +4162,15 @@ eel_canvas_item_class_init (EelCanvasItemClass *klass)
                       G_TYPE_BOOLEAN, 1,
                       GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);
 
+    item_signals[ITEM_DESTROY] =
+        g_signal_new ("destroy",
+		      G_TYPE_FROM_CLASS (klass),
+		      G_SIGNAL_RUN_CLEANUP | G_SIGNAL_NO_RECURSE | G_SIGNAL_NO_HOOKS,
+		      G_STRUCT_OFFSET (EelCanvasItemClass, destroy),
+		      NULL, NULL,
+		      g_cclosure_marshal_VOID__VOID,
+		      G_TYPE_NONE, 0);
+
     klass->realize = eel_canvas_item_realize;
     klass->unrealize = eel_canvas_item_unrealize;
     klass->map = eel_canvas_item_map;
diff --git a/eel/eel-canvas.h b/eel/eel-canvas.h
index 453cdaee..b288dedf 100644
--- a/eel/eel-canvas.h
+++ b/eel/eel-canvas.h
@@ -115,7 +115,7 @@ extern "C" {
 
     struct _EelCanvasItem
     {
-        GtkObject object;
+        GInitiallyUnowned object;
 
         /* Parent canvas for this item */
         EelCanvas *canvas;
@@ -132,7 +132,9 @@ extern "C" {
 
     struct _EelCanvasItemClass
     {
-        GtkObjectClass parent_class;
+        GInitiallyUnownedClass parent_class;
+
+        void (* destroy) (EelCanvasItem *item);
 
         /* Tell the item to update itself.  The flags are from the update flags
          * defined above.  The item should update its internal state from its
@@ -195,6 +197,8 @@ extern "C" {
     EelCanvasItem *eel_canvas_item_new (EelCanvasGroup *parent, GType type,
                                         const gchar *first_arg_name, ...);
 
+    void eel_canvas_item_destroy (EelCanvasItem *item);
+
     /* Constructors for use in derived classes and language wrappers */
     void eel_canvas_item_construct (EelCanvasItem *item, EelCanvasGroup *parent,
                                     const gchar *first_arg_name, va_list args);