-#define GTK_SPIN_BUTTON(obj) (GTK_CHECK_CAST ((obj), GTK_TYPE_SPIN_BUTTON, GtkSpinButton))
-#define GTK_SPIN_BUTTON_CLASS(klass) (GTK_CHECK_CLASS_CAST ((klass), GTK_TYPE_SPIN_BUTTON, GtkSpinButtonClass))
-#define GTK_IS_SPIN_BUTTON(obj) (GTK_CHECK_TYPE ((obj), GTK_TYPE_SPIN_BUTTON))
-#define GTK_IS_SPIN_BUTTON_CLASS(klass) (GTK_CHECK_CLASS_TYPE ((klass), GTK_TYPE_SPIN_BUTTON))
-#define GTK_SPIN_BUTTON_GET_CLASS(obj) (GTK_CHECK_GET_CLASS ((obj), GTK_TYPE_SPIN_BUTTON, GtkSpinButtonClass))
-
+#define GTK_SPIN_BUTTON(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_SPIN_BUTTON, GtkSpinButton))
+#define GTK_SPIN_BUTTON_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_SPIN_BUTTON, GtkSpinButtonClass))
+#define GTK_IS_SPIN_BUTTON(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_SPIN_BUTTON))
+#define GTK_IS_SPIN_BUTTON_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_SPIN_BUTTON))
+#define GTK_SPIN_BUTTON_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_SPIN_BUTTON, GtkSpinButtonClass))
+
+/**
+ * GTK_INPUT_ERROR:
+ *
+ * Constant to return from a signal handler for the #GtkSpinButton::input
+ * signal in case of conversion failure.
+ */