/* GStreamer

 * Copyright (C) 2013 Collabora Ltd.

 *   Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>

 * Copyright (C) 2013 Sebastian Dröge <slomo@circular-chaos.org>

 *

 * gstcontext.h: Header for GstContext subsystem

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifndef __GST_CONTEXT_H__

#define __GST_CONTEXT_H__

#include <glib.h>

G_BEGIN_DECLS

typedef struct _GstContext GstContext;

#include <gst/gstminiobject.h>

#include <gst/gststructure.h>

GST_API GType _gst_context_type;

#define GST_TYPE_CONTEXT                         (_gst_context_type)

#define GST_IS_CONTEXT(obj)                      (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_CONTEXT))

#define GST_CONTEXT_CAST(obj)                    ((GstContext*)(obj))

#define GST_CONTEXT(obj)                         (GST_CONTEXT_CAST(obj))

GST_API

GType           gst_context_get_type            (void);

/* refcounting */

/**

 * gst_context_ref:

 * @context: the context to ref

 *

 * Convenience macro to increase the reference count of the context.

 *

 * Returns: @context (for convenience when doing assignments)

 */

static inline GstContext *

gst_context_ref (GstContext * context)

{

  return (GstContext *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (context));

}

/**

 * gst_context_unref:

 * @context: the context to unref

 *

 * Convenience macro to decrease the reference count of the context, possibly

 * freeing it.

 */

static inline void

gst_context_unref (GstContext * context)

{

  gst_mini_object_unref (GST_MINI_OBJECT_CAST (context));

}

/* copy context */

/**

 * gst_context_copy:

 * @context: the context to copy

 *

 * Creates a copy of the context. Returns a copy of the context.

 *

 * Returns: (transfer full): a new copy of @context.

 *

 * MT safe

 */

static inline GstContext *

gst_context_copy (const GstContext * context)

{

  return GST_CONTEXT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (context)));

}

/**

 * gst_context_is_writable:

 * @context: a #GstContext

 *

 * Tests if you can safely write into a context's structure or validly

 * modify the seqnum and timestamp fields.

 */

#define         gst_context_is_writable(context)     gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (context))

/**

 * gst_context_make_writable:

 * @context: (transfer full): the context to make writable

 *

 * Checks if a context is writable. If not, a writable copy is made and

 * returned.

 *

 * Returns: (transfer full): a context (possibly a duplicate) that is writable.

 *

 * MT safe

 */

#define         gst_context_make_writable(context)  GST_CONTEXT_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (context)))

/**

 * gst_context_replace:

 * @old_context: (inout) (transfer full): pointer to a pointer to a #GstContext

 *     to be replaced.

 * @new_context: (allow-none) (transfer none): pointer to a #GstContext that will

 *     replace the context pointed to by @old_context.

 *

 * Modifies a pointer to a #GstContext to point to a different #GstContext. The

 * modification is done atomically (so this is useful for ensuring thread safety

 * in some cases), and the reference counts are updated appropriately (the old

 * context is unreffed, the new one is reffed).

 *

 * Either @new_context or the #GstContext pointed to by @old_context may be %NULL.

 *

 * Returns: %TRUE if @new_context was different from @old_context

 */

static inline gboolean

gst_context_replace (GstContext **old_context, GstContext *new_context)

{

  return gst_mini_object_replace ((GstMiniObject **) old_context, (GstMiniObject *) new_context);

}

GST_API

GstContext *          gst_context_new                      (const gchar * context_type,

                                                            gboolean persistent) G_GNUC_MALLOC;

GST_API

const gchar *         gst_context_get_context_type         (const GstContext * context);

GST_API

gboolean              gst_context_has_context_type         (const GstContext * context, const gchar * context_type);

GST_API

const GstStructure *  gst_context_get_structure            (const GstContext * context);

GST_API

GstStructure *        gst_context_writable_structure       (GstContext * context);

GST_API

gboolean              gst_context_is_persistent            (const GstContext * context);

#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC

G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstContext, gst_context_unref)

#endif

G_END_DECLS

#endif /* __GST_CONTEXT_H__ */