[libgda] gda-holder: ported to G_DECLARE/G_DEFINE

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit f50f05b21a976e357f3f01f3630174459117480e
Author: Daniel Espinosa <esodan gmail com>
Date:   Wed Sep 19 14:26:43 2018 -0500

    gda-holder: ported to G_DECLARE/G_DEFINE

 libgda/gda-holder.c | 51 +++++----------------------------------------------
 libgda/gda-holder.h | 13 ++-----------
 2 files changed, 7 insertions(+), 57 deletions(-)
---
diff --git a/libgda/gda-holder.c b/libgda/gda-holder.c
index ac1f9a24c..3cedb4acd 100644
--- a/libgda/gda-holder.c
+++ b/libgda/gda-holder.c
@@ -66,8 +66,6 @@ static void bound_holder_changed_cb (GdaHolder *alias_of, GdaHolder *holder);
 static void full_bound_holder_changed_cb (GdaHolder *alias_of, GdaHolder *holder);
 static void gda_holder_set_full_bind (GdaHolder *holder, GdaHolder *alias_of);
 
-/* get a pointer to the parents to be able to call their destructor */
-static GObjectClass  *parent_class = NULL;
 GdaAttributesManager *gda_holder_attributes_manager;
 
 /* signals */
@@ -125,7 +123,9 @@ typedef struct {
 
        gboolean         validate_changes;
 } GdaHolderPrivate;
-#define gda_holder_get_instance_private(obj) G_TYPE_INSTANCE_GET_PRIVATE(obj, GDA_TYPE_HOLDER, 
GdaHolderPrivate)
+G_DEFINE_TYPE_WITH_CODE (GdaHolder, gda_holder, G_TYPE_OBJECT,
+                         G_ADD_PRIVATE (GdaHolder)
+                         G_IMPLEMENT_INTERFACE(GDA_TYPE_LOCKABLE, gda_holder_lockable_init))
 /* module error */
 GQuark gda_holder_error_quark (void)
 {
@@ -135,43 +135,6 @@ GQuark gda_holder_error_quark (void)
         return quark;
 }
 
-GType
-gda_holder_get_type (void)
-{
-       static GType type = 0;
-
-       if (G_UNLIKELY (type == 0)) {
-               static GMutex registering;
-               static const GTypeInfo info = {
-                       sizeof (GdaHolderClass),
-                       (GBaseInitFunc) NULL,
-                       (GBaseFinalizeFunc) NULL,
-                       (GClassInitFunc) gda_holder_class_init,
-                       NULL,
-                       NULL,
-                       sizeof (GdaHolder),
-                       0,
-                       (GInstanceInitFunc) gda_holder_init,
-                       0
-               };
-
-               static GInterfaceInfo lockable_info = {
-                        (GInterfaceInitFunc) gda_holder_lockable_init,
-                       NULL,
-                        NULL
-                };
-               
-               g_mutex_lock (&registering);
-               if (type == 0) {
-                       type = g_type_register_static (G_TYPE_OBJECT, "GdaHolder", &info, 0);
-                       g_type_add_interface_static (type, GDA_TYPE_LOCKABLE, &lockable_info);
-               }
-               g_mutex_unlock (&registering);
-       }
-
-       return type;
-}
-
 static gboolean
 validate_change_accumulator (G_GNUC_UNUSED GSignalInvocationHint *ihint,
                           GValue *return_accu,
@@ -204,10 +167,6 @@ gda_holder_class_init (GdaHolderClass *class)
 {
        GObjectClass *object_class = G_OBJECT_CLASS (class);
 
-       parent_class = g_type_class_peek_parent (class);
-
-       g_type_class_add_private (object_class, sizeof (GdaHolderPrivate));
-
        /**
         * GdaHolder::source-changed:
         * @holder: the #GdaHolder
@@ -594,7 +553,7 @@ gda_holder_dispose (GObject *object)
        }
 
        /* parent class */
-       parent_class->dispose (object);
+       G_OBJECT_CLASS (gda_holder_parent_class)->dispose (object);
 }
 
 static void
@@ -611,7 +570,7 @@ gda_holder_finalize (GObject   * object)
        g_rec_mutex_clear (& (priv->mutex));
 
        /* parent class */
-       parent_class->finalize (object);
+       G_OBJECT_CLASS (gda_holder_parent_class)->finalize (object);
 }
 
 
diff --git a/libgda/gda-holder.h b/libgda/gda-holder.h
index 636f92e4c..286161caf 100644
--- a/libgda/gda-holder.h
+++ b/libgda/gda-holder.h
@@ -28,11 +28,6 @@
 
 G_BEGIN_DECLS
 
-#define GDA_TYPE_HOLDER          (gda_holder_get_type())
-#define GDA_HOLDER(obj)          G_TYPE_CHECK_INSTANCE_CAST (obj, gda_holder_get_type(), GdaHolder)
-#define GDA_HOLDER_CLASS(klass)  G_TYPE_CHECK_CLASS_CAST (klass, gda_holder_get_type (), GdaHolderClass)
-#define GDA_IS_HOLDER(obj)       G_TYPE_CHECK_INSTANCE_TYPE (obj, gda_holder_get_type ())
-
 /* error reporting */
 extern GQuark gda_holder_error_quark (void);
 #define GDA_HOLDER_ERROR gda_holder_error_quark ()
@@ -43,11 +38,8 @@ typedef enum {
        GDA_HOLDER_VALUE_NULL_ERROR
 } GdaHolderError;
 
-/* struct for the object's data */
-struct _GdaHolder
-{
-       GObject                 object;
-};
+#define GDA_TYPE_HOLDER          (gda_holder_get_type())
+G_DECLARE_DERIVABLE_TYPE(GdaHolder, gda_holder, GDA, HOLDER, GObject)
 
 
 /* struct for the object's class */
@@ -83,7 +75,6 @@ struct _GdaHolderClass
  * Each GdaHolder object is thread safe.
  */
 
-GType               gda_holder_get_type                (void) G_GNUC_CONST;
 GdaHolder          *gda_holder_new                     (GType type);
 GdaHolder          *gda_holder_new_inline              (GType type, const gchar *id, ...);
 GdaHolder          *gda_holder_copy                    (GdaHolder *orig);