/* GStreamer X-based Overlay

 * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>

 *

 * x-overlay.c: X-based overlay interface design

 *

 * 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:gstxoverlay

 * @short_description: Interface for setting/getting a Window on elements

 * supporting it

 *

 * <refsect2>

 * <para>

 * The XOverlay interface is used for 2 main purposes :

 * <itemizedlist>

 * <listitem>

 * <para>

 * To get a grab on the Window where the video sink element is going to render.

 * This is achieved by either being informed about the Window identifier that

 * the video sink element generated, or by forcing the video sink element to use

 * a specific Window identifier for rendering.

 * </para>

 * </listitem>

 * <listitem>

 * <para>

 * To force a redrawing of the latest video frame the video sink element

 * displayed on the Window. Indeed if the #GstPipeline is in #GST_STATE_PAUSED

 * state, moving the Window around will damage its content. Application

 * developers will want to handle the Expose events themselves and force the

 * video sink element to refresh the Window's content.

 * </para>

 * </listitem>

 * </itemizedlist>

 * </para>

 * <para>

 * Using the Window created by the video sink is probably the simplest scenario,

 * in some cases, though, it might not be flexible enough for application

 * developers if they need to catch events such as mouse moves and button

 * clicks.

 * </para>

 * <para>

 * Setting a specific Window identifier on the video sink element is the most

 * flexible solution but it has some issues. Indeed the application needs to set

 * its Window identifier at the right time to avoid internal Window creation

 * from the video sink element. To solve this issue a #GstMessage is posted on

 * the bus to inform the application that it should set the Window identifier

 * immediately. Here is an example on how to do that correctly:

 * <programlisting>

 * static GstBusSyncReply

 * create_window (GstBus * bus, GstMessage * message, GstPipeline * pipeline)

 * {

 *  // ignore anything but 'prepare-xwindow-id' element messages

 *  if (GST_MESSAGE_TYPE (message) != GST_MESSAGE_ELEMENT)

 *    return GST_BUS_PASS;

 *  

 *  if (!gst_structure_has_name (message->structure, "prepare-xwindow-id"))

 *    return GST_BUS_PASS;

 *  

 *  win = XCreateSimpleWindow (disp, root, 0, 0, 320, 240, 0, 0, 0);

 *  

 *  XSetWindowBackgroundPixmap (disp, win, None);

 *  

 *  XMapRaised (disp, win);

 *  

 *  XSync (disp, FALSE);

 *   

 *  gst_x_overlay_set_xwindow_id (GST_X_OVERLAY (GST_MESSAGE_SRC (message)),

 *      win);

 *   

 *  gst_message_unref (message);

 *   

 *  return GST_BUS_DROP;

 * }

 * ...

 * int

 * main (int argc, char **argv)

 * {

 * ...

 *  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));

 *  gst_bus_set_sync_handler (bus, (GstBusSyncHandler) create_window, pipeline);

 * ...

 * }

 * </programlisting>

 * </para>

 * </refsect2>

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "xoverlay.h"

static void gst_x_overlay_base_init (gpointer g_class);

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GType

gst_x_overlay_get_type (void)

{

  static GType gst_x_overlay_type = 0;

  if (!gst_x_overlay_type) {

    static const GTypeInfo gst_x_overlay_info = {

      sizeof (GstXOverlayClass),

      gst_x_overlay_base_init,

      NULL,

      NULL,

      NULL,

      NULL,

      0,

      0,

      NULL,

    };

    gst_x_overlay_type = g_type_register_static (G_TYPE_INTERFACE,

        "GstXOverlay", &gst_x_overlay_info, 0);

    g_type_interface_add_prerequisite (gst_x_overlay_type,

        GST_TYPE_IMPLEMENTS_INTERFACE);

  }

  return gst_x_overlay_type;

}

static void

gst_x_overlay_base_init (gpointer g_class)

{

  GstXOverlayClass *overlay_class = (GstXOverlayClass *) g_class;

  overlay_class->set_xwindow_id = NULL;

}

/**

 * gst_x_overlay_set_xwindow_id:

 * @overlay: a #GstXOverlay to set the XWindow on.

 * @xwindow_id: a #XID referencing the XWindow.

 *

 * This will call the video overlay's set_xwindow_id method. You should

 * use this method to tell to a XOverlay to display video output to a

 * specific XWindow. Passing 0 as the xwindow_id will tell the overlay to

 * stop using that window and create an internal one.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_x_overlay_set_xwindow_id (GstXOverlay * overlay, gulong xwindow_id)

{

  GstXOverlayClass *klass;

  g_return_if_fail (overlay != NULL);

  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  klass = GST_X_OVERLAY_GET_CLASS (overlay);

  if (klass->set_xwindow_id) {

    klass->set_xwindow_id (overlay, xwindow_id);

  }

}

/**

 * gst_x_overlay_got_xwindow_id:

 * @overlay: a #GstXOverlay which got a XWindow.

 * @xwindow_id: a #XID referencing the XWindow.

 *

 * This will post a "have-xwindow-id" element message on the bus.

 *

 * This function should only be used by video overlay plugin developers.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_x_overlay_got_xwindow_id (GstXOverlay * overlay, gulong xwindow_id)

{

  GstStructure *s;

  GstMessage *msg;

  g_return_if_fail (overlay != NULL);

  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  GST_LOG_OBJECT (GST_OBJECT (overlay), "xwindow_id = %lu", xwindow_id);

  s = gst_structure_new ("have-xwindow-id", "xwindow-id", G_TYPE_ULONG,

      xwindow_id, NULL);

  msg = gst_message_new_element (GST_OBJECT (overlay), s);

  gst_element_post_message (GST_ELEMENT (overlay), msg);

}

/**

 * gst_x_overlay_prepare_xwindow_id:

 * @overlay: a #GstXOverlay which does not yet have an XWindow.

 *

 * This will post a "prepare-xwindow-id" element message on the bus

 * to give applications an opportunity to call 

 * gst_x_overlay_set_xwindow_id() before a plugin creates its own

 * window.

 *

 * This function should only be used by video overlay plugin developers.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_x_overlay_prepare_xwindow_id (GstXOverlay * overlay)

{

  GstStructure *s;

  GstMessage *msg;

  g_return_if_fail (overlay != NULL);

  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  GST_LOG_OBJECT (GST_OBJECT (overlay), "prepare xwindow_id");

  s = gst_structure_new ("prepare-xwindow-id", NULL);

  msg = gst_message_new_element (GST_OBJECT (overlay), s);

  gst_element_post_message (GST_ELEMENT (overlay), msg);

}

/**

 * gst_x_overlay_expose:

 * @overlay: a #GstXOverlay to expose.

 *

 * Tell an overlay that it has been exposed. This will redraw the current frame

 * in the drawable even if the pipeline is PAUSED.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_x_overlay_expose (GstXOverlay * overlay)

{

  GstXOverlayClass *klass;

  g_return_if_fail (overlay != NULL);

  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  klass = GST_X_OVERLAY_GET_CLASS (overlay);

  if (klass->expose) {

    klass->expose (overlay);

  }

}

/**

 * gst_x_overlay_handle_events:

 * @overlay: a #GstXOverlay to expose.

 * @handle_events: a #gboolean indicating if events should be handled or not.

 *

 * Tell an overlay that it should handle events from the window system. These

 * events are forwared upstream as navigation events. In some window system,

 * events are not propagated in the window hierarchy if a client is listening

 * for them. This method allows you to disable events handling completely

 * from the XOverlay.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_x_overlay_handle_events (GstXOverlay * overlay, gboolean handle_events)

{

  GstXOverlayClass *klass;

  g_return_if_fail (overlay != NULL);

  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  klass = GST_X_OVERLAY_GET_CLASS (overlay);

  if (klass->handle_events) {

    klass->handle_events (overlay, handle_events);

  }

}