[pango/pango2: 1/135] Add PANGO_DECLARE_INTERNAL_TYPE

[Matthias Clasen <matthiasc src gnome org>]

commit 84f3f2f7906ab21f31391c37c564339893c15466
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Dec 23 08:48:14 2021 -0500

    Add PANGO_DECLARE_INTERNAL_TYPE
    
    This will be used in future commits for
    making types that can be internally derived
    without exposing them to 3rd parties.

 pango/pango-types.h | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
---
diff --git a/pango/pango-types.h b/pango/pango-types.h
index e12d8814..5d1b30df 100644
--- a/pango/pango-types.h
+++ b/pango/pango-types.h
@@ -239,6 +239,46 @@ void pango_extents_to_pixels (PangoRectangle *inclusive,
 #include <pango/pango-script.h>
 
 
+/*
+ * PANGO_DECLARE_INTERNAL_TYPE:
+ * @ModuleObjName: The name of the new type, in camel case (like GtkWidget)
+ * @module_obj_name: The name of the new type in lowercase, with words
+ *  separated by '_' (like 'gtk_widget')
+ * @MODULE: The name of the module, in all caps (like 'GTK')
+ * @OBJ_NAME: The bare name of the type, in all caps (like 'WIDGET')
+ * @ParentName: the name of the parent type, in camel case (like GtkWidget)
+ *
+ * A convenience macro for emitting the usual declarations in the
+ * header file for a type which is intended to be subclassed only
+ * by internal consumers.
+ *
+ * This macro differs from %G_DECLARE_DERIVABLE_TYPE and %G_DECLARE_FINAL_TYPE
+ * by declaring a type that is only derivable internally. Internal users can
+ * derive this type, assuming they have access to the instance and class
+ * structures; external users will not be able to subclass this type.
+ */
+#define PANGO_DECLARE_INTERNAL_TYPE(ModuleObjName, module_obj_name, MODULE, OBJ_NAME, ParentName) \
+  GType module_obj_name##_get_type (void);                                                               \
+  G_GNUC_BEGIN_IGNORE_DEPRECATIONS                                                                       \
+  typedef struct _##ModuleObjName ModuleObjName;                                                         \
+  typedef struct _##ModuleObjName##Class ModuleObjName##Class;                                           \
+                                                                                                         \
+  _GLIB_DEFINE_AUTOPTR_CHAINUP (ModuleObjName, ParentName)                                               \
+  G_DEFINE_AUTOPTR_CLEANUP_FUNC (ModuleObjName##Class, g_type_class_unref)                               \
+                                                                                                         \
+  G_GNUC_UNUSED static inline ModuleObjName * MODULE##_##OBJ_NAME (gpointer ptr) {                       \
+    return G_TYPE_CHECK_INSTANCE_CAST (ptr, module_obj_name##_get_type (), ModuleObjName); }             \
+  G_GNUC_UNUSED static inline ModuleObjName##Class * MODULE##_##OBJ_NAME##_CLASS (gpointer ptr) {        \
+    return G_TYPE_CHECK_CLASS_CAST (ptr, module_obj_name##_get_type (), ModuleObjName##Class); }         \
+  G_GNUC_UNUSED static inline gboolean MODULE##_IS_##OBJ_NAME (gpointer ptr) {                           \
+    return G_TYPE_CHECK_INSTANCE_TYPE (ptr, module_obj_name##_get_type ()); }                            \
+  G_GNUC_UNUSED static inline gboolean MODULE##_IS_##OBJ_NAME##_CLASS (gpointer ptr) {                   \
+    return G_TYPE_CHECK_CLASS_TYPE (ptr, module_obj_name##_get_type ()); }                               \
+  G_GNUC_UNUSED static inline ModuleObjName##Class * MODULE##_##OBJ_NAME##_GET_CLASS (gpointer ptr) {    \
+    return G_TYPE_INSTANCE_GET_CLASS (ptr, module_obj_name##_get_type (), ModuleObjName##Class); }       \
+  G_GNUC_END_IGNORE_DEPRECATIONS
+
+
 G_END_DECLS
 
 #endif /* __PANGO_TYPES_H__ */