/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *                    2000 Wim Taymans <wim.taymans@chello.be>

 *                    2005 Wim Taymans <wim@fluendo.com>

 *

 * gstevent.c: GstEvent 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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/**

 * SECTION:gstevent

 * @short_description: Structure describing events that are passed up and down

 *                     a pipeline

 * @see_also: #GstPad, #GstElement

 *

 * The event class provides factory methods to construct and functions query

 * (parse) events.

 *

 * Events are usually created with gst_event_new_*() which takes event-type

 * specific parameters as arguments.

 * To send an event application will usually use gst_element_send_event() and

 * elements will use gst_pad_send_event() or gst_pad_push_event().

 * The event should be unreffed with gst_event_unref() if it has not been sent.

 *

 * Events that have been received can be parsed with their respective 

 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.

 *

 * Events are passed between elements in parallel to the data stream. Some events

 * are serialized with buffers, others are not. Some events only travel downstream,

 * others only upstream. Some events can travel both upstream and downstream. 

 * 

 * The events are used to signal special conditions in the datastream such as

 * EOS (end of stream) or the start of a new stream-segment.

 * Events are also used to flush the pipeline of any pending data.

 *

 * Most of the event API is used inside plugins. Applications usually only 

 * construct and use seek events. 

 * To do that gst_event_new_seek() is used to create a seek event. It takes

 * the needed parameters to specity seeking time and mode.

 * <example>

 * <title>performing a seek on a pipeline</title>

 *   <programlisting>

 *   GstEvent *event;

 *   gboolean result;

 *   ...

 *   // construct a seek event to play the media from second 2 to 5, flush

 *   // the pipeline to decrease latency.

 *   event = gst_event_new_seek (1.0, 

 *      GST_FORMAT_TIME, 

 *      GST_SEEK_FLAG_FLUSH,

 *      GST_SEEK_TYPE_SET, 2 * GST_SECOND,

 *      GST_SEEK_TYPE_SET, 5 * GST_SECOND);

 *   ...

 *   result = gst_element_send_event (pipeline, event);

 *   if (!result)

 *     g_warning ("seek failed");

 *   ...

 *   </programlisting>

 * </example>

 *

 * Last reviewed on 2006-09-6 (0.10.10)

 */

#include "gst_private.h"

#include <string.h>             /* memcpy */

#include "gstinfo.h"

#include "gstevent.h"

#include "gstenumtypes.h"

#include "gstutils.h"

#include "gstquark.h"

#define GST_EVENT_SEQNUM(e) ((GstEvent*)e)->abidata.seqnum

static void gst_event_finalize (GstEvent * event);

static GstEvent *_gst_event_copy (GstEvent * event);

static GstMiniObjectClass *parent_class = NULL;

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

_gst_event_initialize (void)

{

  g_type_class_ref (gst_event_get_type ());

  g_type_class_ref (gst_seek_flags_get_type ());

  g_type_class_ref (gst_seek_type_get_type ());

}

typedef struct

{

  const gint type;

  const gchar *name;

  GQuark quark;

} GstEventQuarks;

static GstEventQuarks event_quarks[] = {

  {GST_EVENT_UNKNOWN, "unknown", 0},

  {GST_EVENT_FLUSH_START, "flush-start", 0},

  {GST_EVENT_FLUSH_STOP, "flush-stop", 0},

  {GST_EVENT_EOS, "eos", 0},

  {GST_EVENT_NEWSEGMENT, "newsegment", 0},

  {GST_EVENT_TAG, "tag", 0},

  {GST_EVENT_BUFFERSIZE, "buffersize", 0},

  {GST_EVENT_QOS, "qos", 0},

  {GST_EVENT_SEEK, "seek", 0},

  {GST_EVENT_NAVIGATION, "navigation", 0},

  {GST_EVENT_LATENCY, "latency", 0},

  {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},

  {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},

  {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},

  {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},

  {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},

  {0, NULL, 0}

};

/**

 * gst_event_type_get_name:

 * @type: the event type

 *

 * Get a printable name for the given event type. Do not modify or free.

 *

 * Returns: a reference to the static name of the event.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

const gchar *

gst_event_type_get_name (GstEventType type)

{

  gint i;

  for (i = 0; event_quarks[i].name; i++) {

    if (type == event_quarks[i].type)

      return event_quarks[i].name;

  }

  return "unknown";

}

/**

 * gst_event_type_to_quark:

 * @type: the event type

 *

 * Get the unique quark for the given event type.

 *

 * Returns: the quark associated with the event type

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GQuark

gst_event_type_to_quark (GstEventType type)

{

  gint i;

  for (i = 0; event_quarks[i].name; i++) {

    if (type == event_quarks[i].type)

      return event_quarks[i].quark;

  }

  return 0;

}

/**

 * gst_event_type_get_flags:

 * @type: a #GstEventType

 *

 * Gets the #GstEventTypeFlags associated with @type.

 *

 * Returns: a #GstEventTypeFlags.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstEventTypeFlags

gst_event_type_get_flags (GstEventType type)

{

  GstEventTypeFlags ret;

  ret = type & ((1 << GST_EVENT_TYPE_SHIFT) - 1);

  return ret;

}

#define _do_init \

{ \

  gint i; \

  \

  for (i = 0; event_quarks[i].name; i++) { \

    event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name); \

  } \

}

G_DEFINE_TYPE_WITH_CODE (GstEvent, gst_event, GST_TYPE_MINI_OBJECT, _do_init);

static void

gst_event_class_init (GstEventClass * klass)

{

  parent_class = g_type_class_peek_parent (klass);

  klass->mini_object_class.copy = (GstMiniObjectCopyFunction) _gst_event_copy;

  klass->mini_object_class.finalize =

      (GstMiniObjectFinalizeFunction) gst_event_finalize;

}

static void

gst_event_init (GstEvent * event)

{

  GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;

}

static void

gst_event_finalize (GstEvent * event)

{

  g_return_if_fail (event != NULL);

  g_return_if_fail (GST_IS_EVENT (event));

  GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,

      GST_EVENT_TYPE_NAME (event));

  if (GST_EVENT_SRC (event)) {

    gst_object_unref (GST_EVENT_SRC (event));

    GST_EVENT_SRC (event) = NULL;

  }

  if (event->structure) {

    gst_structure_set_parent_refcount (event->structure, NULL);

    gst_structure_free (event->structure);

  }

/*   GST_MINI_OBJECT_CLASS (parent_class)->finalize (GST_MINI_OBJECT (event)); */

}

static GstEvent *

_gst_event_copy (GstEvent * event)

{

  GstEvent *copy;

  copy = (GstEvent *) gst_mini_object_new (GST_TYPE_EVENT);

  GST_EVENT_TYPE (copy) = GST_EVENT_TYPE (event);

  GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);

  GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);

  if (GST_EVENT_SRC (event)) {

    GST_EVENT_SRC (copy) = gst_object_ref (GST_EVENT_SRC (event));

  }

  if (event->structure) {

    copy->structure = gst_structure_copy (event->structure);

    gst_structure_set_parent_refcount (copy->structure,

        &copy->mini_object.refcount);

  }

  return copy;

}

static GstEvent *

gst_event_new (GstEventType type)

{

  GstEvent *event;

  event = (GstEvent *) gst_mini_object_new (GST_TYPE_EVENT);

  GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,

      gst_event_type_get_name (type), type);

  event->type = type;

  event->src = NULL;

  event->structure = NULL;

  GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();

  return event;

}

/**

 * gst_event_new_custom:

 * @type: The type of the new event

 * @structure: The structure for the event. The event will take ownership of

 * the structure.

 *

 * Create a new custom-typed event. This can be used for anything not

 * handled by other event-specific functions to pass an event to another

 * element.

 *

 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,

 * assigning a free number and filling in the correct direction and

 * serialization flags.

 *

 * New custom events can also be created by subclassing the event type if

 * needed.

 *

 * Returns: The new custom event.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstEvent *

gst_event_new_custom (GstEventType type, GstStructure * structure)

{

  GstEvent *event;

  /* structure must not have a parent */

  if (structure)

    g_return_val_if_fail (structure->parent_refcount == NULL, NULL);

  event = gst_event_new (type);

  if (structure) {

    gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);

    event->structure = structure;

  }

  return event;

}

/**

 * gst_event_get_structure:

 * @event: The #GstEvent.

 *

 * Access the structure of the event.

 *

 * Returns: The structure of the event. The structure is still

 * owned by the event, which means that you should not free it and

 * that the pointer becomes invalid when you free the event.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

const GstStructure *

gst_event_get_structure (GstEvent * event)

{

  g_return_val_if_fail (GST_IS_EVENT (event), NULL);

  return event->structure;

}

/**

 * gst_event_has_name:

 * @event: The #GstEvent.

 * @name: name to check

 *

 * Checks if @event has the given @name. This function is usually used to

 * check the name of a custom event.

 *

 * Returns: %TRUE if @name matches the name of the event structure.

 *

 * Since: 0.10.20

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gboolean

gst_event_has_name (GstEvent * event, const gchar * name)

{

  g_return_val_if_fail (GST_IS_EVENT (event), FALSE);

  if (event->structure == NULL)

    return FALSE;

  return gst_structure_has_name (event->structure, name);

}

/**

 * gst_event_get_seqnum:

 * @event: A #GstEvent.

 *

 * Retrieve the sequence number of a event.

 *

 * Events have ever-incrementing sequence numbers, which may also be set

 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to

 * indicate that a event corresponds to some other set of events or messages,

 * for example an EOS event corresponding to a SEEK event. It is considered good

 * practice to make this correspondence when possible, though it is not

 * required.

 *

 * Note that events and messages share the same sequence number incrementor;

 * two events or messages will never not have the same sequence number unless

 * that correspondence was made explicitly.

 *

 * Returns: The event's sequence number.

 *

 * MT safe.

 *

 * Since: 0.10.22

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

guint32

gst_event_get_seqnum (GstEvent * event)

{

  g_return_val_if_fail (GST_IS_EVENT (event), -1);

  return GST_EVENT_SEQNUM (event);

}

/**

 * gst_event_set_seqnum:

 * @event: A #GstEvent.

 * @seqnum: A sequence number.

 *

 * Set the sequence number of a event.

 *

 * This function might be called by the creator of a event to indicate that the

 * event relates to other events or messages. See gst_event_get_seqnum() for

 * more information.

 *

 * MT safe.

 *

 * Since: 0.10.22

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_event_set_seqnum (GstEvent * event, guint32 seqnum)

{

  g_return_if_fail (GST_IS_EVENT (event));

  GST_EVENT_SEQNUM (event) = seqnum;

}

/**

 * gst_event_new_flush_start:

 *

 * Allocate a new flush start event. The flush start event can be sent

 * upstream and downstream and travels out-of-bounds with the dataflow.

 *

 * It marks pads as being flushing and will make them return

 * #GST_FLOW_WRONG_STATE when used for data flow with gst_pad_push(),

 * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and

 * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received

 * on a flushing pad will return %FALSE immediately.

 *

 * Elements should unlock any blocking functions and exit their streaming

 * functions as fast as possible when this event is received.

 *

 * This event is typically generated after a seek to flush out all queued data

 * in the pipeline so that the new media is played as soon as possible.

 *

 * Returns: A new flush start event.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstEvent *

gst_event_new_flush_start (void)

{

  return gst_event_new (GST_EVENT_FLUSH_START);

}

/**

 * gst_event_new_flush_stop:

 *

 * Allocate a new flush stop event. The flush stop event can be sent

 * upstream and downstream and travels out-of-bounds with the dataflow.

 * It is typically sent after sending a FLUSH_START event to make the

 * pads accept data again.

 *

 * Elements can process this event synchronized with the dataflow since

 * the preceeding FLUSH_START event stopped the dataflow.

 *

 * This event is typically generated to complete a seek and to resume

 * dataflow.

 *

 * Returns: A new flush stop event.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstEvent *

gst_event_new_flush_stop (void)

{

  return gst_event_new (GST_EVENT_FLUSH_STOP);

}

/**

 * gst_event_new_eos:

 *

 * Create a new EOS event. The eos event can only travel downstream

 * synchronized with the buffer flow. Elements that receive the EOS

 * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn

 * when data after the EOS event arrives.

 *

 * The EOS event will travel down to the sink elements in the pipeline

 * which will then post the #GST_MESSAGE_EOS on the bus after they have

 * finished playing any buffered data.

 *

 * When all sinks have posted an EOS message, an EOS message is

 * forwarded to the application.

 *

 * Returns: The new EOS event.

 */

#ifdef __SYMBIAN32__