math-preferences: avoid deprecated 'g_type_class_add_private'

Author: sc0w

src/math-preferences.c

@@ -14,7 +14,6 @@
 #include "math-preferences.h"
 #include "utility.h"
 
-G_DEFINE_TYPE (MathPreferencesDialog, math_preferences, GTK_TYPE_DIALOG);
 
 enum {
     PROP_0,
@@ -27,6 +26,8 @@ struct MathPreferencesDialogPrivate
     GtkBuilder *ui;
 };
 
+G_DEFINE_TYPE_WITH_PRIVATE (MathPreferencesDialog, math_preferences, GTK_TYPE_DIALOG);
+
 #define UI_DIALOGS_FILE  UI_DIR "/preferences.ui"
 #define GET_WIDGET(ui, name) \
           GTK_WIDGET(gtk_builder_get_object(ui, name))
@@ -386,8 +387,6 @@ math_preferences_class_init(MathPreferencesDialogClass *klass)
     object_class->get_property = math_preferences_get_property;
     object_class->set_property = math_preferences_set_property;
 
-    g_type_class_add_private(klass, sizeof(MathPreferencesDialogPrivate));
-
     g_object_class_install_property(object_class,
                                     PROP_EQUATION,
                                     g_param_spec_object("equation",
@@ -401,5 +400,5 @@ math_preferences_class_init(MathPreferencesDialogClass *klass)
 static void
 math_preferences_init(MathPreferencesDialog *dialog)
 {
-    dialog->priv = G_TYPE_INSTANCE_GET_PRIVATE(dialog, math_preferences_get_type(), MathPreferencesDialogPrivate);
+    dialog->priv = math_preferences_get_instance_private (dialog);
 }