mutter/cogl/cogl/cogl-object.h

/*
 * Cogl
 *
 * A Low Level GPU Graphics and Utilities API
 *
 * Copyright (C) 2009,2010 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 *
 */

#ifndef __COGL_OBJECT_H
#define __COGL_OBJECT_H

#include <cogl/cogl-types.h>

#include <glib-object.h>

G_BEGIN_DECLS

typedef struct _CoglObject      CoglObject;

#define COGL_OBJECT(X)          ((CoglObject *)X)

/**
 * CoglObject: (ref-func cogl_object_ref) (unref-func cogl_object_unref)
 *     (set-value-func cogl_object_value_set_object)
 *     (get-value-func cogl_object_value_get_object)
 */

/**
 * cogl_object_get_gtype:
 *
 * Returns: a #GType that can be used with the GLib type system.
 */
COGL_EXPORT
GType cogl_object_get_gtype (void);

/**
 * cogl_object_ref: (skip)
 * @object: a #CoglObject
 *
 * Increases the reference count of @object by 1
 *
 * Returns: the @object, with its reference count increased
 */
COGL_EXPORT void *
cogl_object_ref (void *object);

/**
 * cogl_object_unref: (skip)
 * @object: a #CoglObject
 *
 * Drecreases the reference count of @object by 1; if the reference
 * count reaches 0, the resources allocated by @object will be freed
 */
COGL_EXPORT void
cogl_object_unref (void *object);

/**
 * cogl_clear_object: (skip)
 * @object_ptr: a pointer to a #CoglObject reference
 *
 * Clears a reference to a #CoglObject.
 *
 * @object_ptr must not be %NULL.
 *
 * If the reference is %NULL then this function does nothing.
 * Otherwise, the reference count of the object is decreased using
 * cogl_object_unref() and the pointer is set to %NULL.
 */
#define cogl_clear_object(object_ptr) g_clear_pointer ((object_ptr), cogl_object_unref)

/**
 * CoglUserDataKey:
 * @unused: ignored.
 *
 * A #CoglUserDataKey is used to declare a key for attaching data to a
 * #CoglObject using cogl_object_set_user_data. The typedef only exists as a
 * formality to make code self documenting since only the unique address of a
 * #CoglUserDataKey is used.
 *
 * Typically you would declare a static #CoglUserDataKey and set private data
 * on an object something like this:
 *
 * |[
 * static CoglUserDataKey path_private_key;
 *
 * static void
 * destroy_path_private_cb (void *data)
 * {
 *   g_free (data);
 * }
 *
 * static void
 * my_path_set_data (CoglPipeline *pipeline, void *data)
 * {
 *   cogl_object_set_user_data (COGL_OBJECT (pipeline),
 *                              &private_key,
 *                              data,
 *                              destroy_pipeline_private_cb);
 * }
 * ]|
 */
typedef struct {
  int unused;
} CoglUserDataKey;

/**
 * CoglUserDataDestroyCallback:
 * @user_data: The data whose association with a #CoglObject has been
 *             destroyed.
 *
 * When associating private data with a #CoglObject a callback can be
 * given which will be called either if the object is destroyed or if
 * cogl_object_set_user_data() is called with NULL user_data for the
 * same key.
 */
typedef GDestroyNotify CoglUserDataDestroyCallback;

/**
 * CoglDebugObjectTypeInfo:
 * @name: A human readable name for the type.
 * @instance_count: The number of objects of this type that are
 *   currently in use
 *
 * This struct is used to pass information to the callback when
 * cogl_debug_object_foreach_type() is called.
 */
typedef struct {
  const char *name;
  unsigned long instance_count;
} CoglDebugObjectTypeInfo;

/**
 * CoglDebugObjectForeachTypeCallback:
 * @info: A pointer to a struct containing information about the type.
 *
 * A callback function to use for cogl_debug_object_foreach_type().
 */
typedef void
(* CoglDebugObjectForeachTypeCallback) (const CoglDebugObjectTypeInfo *info,
                                        void *user_data);

/**
 * cogl_object_set_user_data: (skip)
 * @object: The object to associate private data with
 * @key: The address of a #CoglUserDataKey which provides a unique value
 *   with which to index the private data.
 * @user_data: The data to associate with the given object,
 *   or %NULL to remove a previous association.
 * @destroy: A #CoglUserDataDestroyCallback to call if the object is
 *   destroyed or if the association is removed by later setting
 *   %NULL data for the same key.
 *
 * Associates some private @user_data with a given #CoglObject. To
 * later remove the association call cogl_object_set_user_data() with
 * the same @key but NULL for the @user_data.
 */
COGL_EXPORT void
cogl_object_set_user_data (CoglObject *object,
                           CoglUserDataKey *key,
                           void *user_data,
                           CoglUserDataDestroyCallback destroy);

/**
 * cogl_object_get_user_data: (skip)
 * @object: The object with associated private data to query
 * @key: The address of a #CoglUserDataKey which provides a unique value
 *       with which to index the private data.
 *
 * Finds the user data previously associated with @object using
 * the given @key. If no user data has been associated with @object
 * for the given @key this function returns NULL.
 *
 * Returns: (transfer none): The user data previously associated
 *   with @object using the given @key; or %NULL if no associated
 *   data is found.
 */
COGL_EXPORT void *
cogl_object_get_user_data (CoglObject *object,
                           CoglUserDataKey *key);

/**
 * cogl_debug_object_foreach_type:
 * @func: (scope call): A callback function for each type
 * @user_data: (closure): A pointer to pass to @func
 *
 * Invokes @func once for each type of object that Cogl uses and
 * passes a count of the number of objects for that type. This is
 * intended to be used solely for debugging purposes to track down
 * issues with objects leaking.
 */
COGL_EXPORT void
cogl_debug_object_foreach_type (CoglDebugObjectForeachTypeCallback func,
                                void *user_data);

/**
 * cogl_debug_object_print_instances:
 *
 * Prints a list of all the object types that Cogl uses along with the
 * number of objects of that type that are currently in use. This is
 * intended to be used solely for debugging purposes to track down
 * issues with objects leaking.
 */
COGL_EXPORT void
cogl_debug_object_print_instances (void);

G_END_DECLS

#endif /* __COGL_OBJECT_H */