GtkActivatable

enum{
...

PROP_ACTIVATABLE_RELATED_ACTION,
PROP_ACTIVATABLE_USE_ACTION_APPEARANCE
}

struct_FooBarPrivate
{

...

GtkAction*action;
gboolean        use_action_appearance;
};

...

staticvoidfoo_bar_activatable_interface_init(GtkActivatableIface*iface);
staticvoidfoo_bar_activatable_update(GtkActivatable*activatable,
GtkAction*action,
constgchar*property_name);
staticvoidfoo_bar_activatable_sync_action_properties(GtkActivatable*activatable,
GtkAction*action);
...


staticvoid
foo_bar_class_init(FooBarClass*klass)
{

...

g_object_class_override_property(gobject_class, PROP_ACTIVATABLE_RELATED_ACTION,"related-action");
g_object_class_override_property(gobject_class, PROP_ACTIVATABLE_USE_ACTION_APPEARANCE,"use-action-appearance");

...
}


staticvoid
foo_bar_activatable_interface_init(GtkActivatableIface*iface)
{
  iface->update = foo_bar_activatable_update;
  iface->sync_action_properties = foo_bar_activatable_sync_action_properties;
}

... Break the reference usinggtk_activatable_do_set_related_action()...

staticvoid
foo_bar_dispose(GObject*object)
{
FooBar*bar =FOO_BAR(object);
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(bar);

...

if(priv->action)
{
gtk_activatable_do_set_related_action(GTK_ACTIVATABLE(bar), NULL);
      priv->action = NULL;
}
G_OBJECT_CLASS(foo_bar_parent_class)->dispose(object);
}

... Handle the “related-action” and “use-action-appearance” properties ...

staticvoid
foo_bar_set_property(GObject*object,
guint            prop_id,
constGValue*value,
GParamSpec*pspec)
{
FooBar*bar =FOO_BAR(object);
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(bar);

switch(prop_id)
{

...

case PROP_ACTIVATABLE_RELATED_ACTION:
foo_bar_set_related_action(bar,g_value_get_object(value));
break;
case PROP_ACTIVATABLE_USE_ACTION_APPEARANCE:
foo_bar_set_use_action_appearance(bar,g_value_get_boolean(value));
break;
    default:
G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
break;
}
}

staticvoid
foo_bar_get_property(GObject*object,
guint            prop_id,
GValue*value,
GParamSpec*pspec)
{
FooBar*bar =FOO_BAR(object);
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(bar);

switch(prop_id)
{

...

case PROP_ACTIVATABLE_RELATED_ACTION:
g_value_set_object(value, priv->action);
break;
case PROP_ACTIVATABLE_USE_ACTION_APPEARANCE:
g_value_set_boolean(value, priv->use_action_appearance);
break;
    default:
G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
break;
}
}


staticvoid
foo_bar_set_use_action_appearance(FooBar*bar,
gboolean  use_appearance)
{
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(bar);

if(priv->use_action_appearance != use_appearance)
{
      priv->use_action_appearance = use_appearance;

gtk_activatable_sync_action_properties(GTK_ACTIVATABLE(bar), priv->action);
}
}

...callgtk_activatable_do_set_related_action() and then assign the action pointer,
no need to reference the action here sincegtk_activatable_do_set_related_action() already 
holds a reference here for you...
staticvoid
foo_bar_set_related_action(FooBar*bar,
GtkAction*action)
{
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(bar);

if(priv->action == action)
return;

gtk_activatable_do_set_related_action(GTK_ACTIVATABLE(bar), action);

  priv->action = action;
}

... Selectively reset and update activatable depending on the use-action-appearance property ...
staticvoid
gtk_button_activatable_sync_action_properties(GtkActivatable*activatable,
GtkAction*action)
{
GtkButtonPrivate*priv =GTK_BUTTON_GET_PRIVATE(activatable);

if(!action)
return;

if(gtk_action_is_visible(action))
gtk_widget_show(GTK_WIDGET(activatable));
else
gtk_widget_hide(GTK_WIDGET(activatable));

gtk_widget_set_sensitive(GTK_WIDGET(activatable),gtk_action_is_sensitive(action));

...

if(priv->use_action_appearance)
{
if(gtk_action_get_stock_id(action))
foo_bar_set_stock(button,gtk_action_get_stock_id(action));
elseif(gtk_action_get_label(action))
foo_bar_set_label(button,gtk_action_get_label(action));

...

}
}

staticvoid
foo_bar_activatable_update(GtkActivatable*activatable,
GtkAction*action,
constgchar*property_name)
{
FooBarPrivate*priv =FOO_BAR_GET_PRIVATE(activatable);

if(strcmp(property_name,"visible")==0)
{
if(gtk_action_is_visible(action))
gtk_widget_show(GTK_WIDGET(activatable));
else
gtk_widget_hide(GTK_WIDGET(activatable));
}
elseif(strcmp(property_name,"sensitive")==0)
gtk_widget_set_sensitive(GTK_WIDGET(activatable),gtk_action_is_sensitive(action));

...

if(!priv->use_action_appearance)
return;

if(strcmp(property_name,"stock-id")==0)
foo_bar_set_stock(button,gtk_action_get_stock_id(action));
elseif(strcmp(property_name,"label")==0)
foo_bar_set_label(button,gtk_action_get_label(action));

...
}