Add gtkhdytype.h

This will help importing Handy classes.

gtk/gtkhdytype.h

+/*
+ * Copyright (C) 2019 Purism SPC
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ */
+
+#pragma once
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define GTK_HDY_DECLARE_DERIVABLE_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;                                           \
+  struct _##ModuleObjName { ParentName parent_instance; };                                               \
+                                                                                                         \
+  G_DEFINE_AUTOPTR_CLEANUP_FUNC (ModuleObjName, g_object_unref)                                               \
+                                                                                                         \
+  static inline ModuleObjName * MODULE##_##OBJ_NAME (gpointer ptr) {                                     \
+    return G_TYPE_CHECK_INSTANCE_CAST (ptr, module_obj_name##_get_type (), ModuleObjName); }             \
+  static inline ModuleObjName##Class * MODULE##_##OBJ_NAME##_CLASS (gpointer ptr) {                      \
+    return G_TYPE_CHECK_CLASS_CAST (ptr, module_obj_name##_get_type (), ModuleObjName##Class); }         \
+  static inline gboolean MODULE##_IS_##OBJ_NAME (gpointer ptr) {                                         \
+    return G_TYPE_CHECK_INSTANCE_TYPE (ptr, module_obj_name##_get_type ()); }                            \
+  static inline gboolean MODULE##_IS_##OBJ_NAME##_CLASS (gpointer ptr) {                                 \
+    return G_TYPE_CHECK_CLASS_TYPE (ptr, module_obj_name##_get_type ()); }                               \
+  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