gstreamer/gst-libs/gst/xoverlay/xoverlay.c

/* GStreamer X-based Overlay
 * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
 *
 * tv-mixer.c: tv-mixer design virtual class function wrappers
 *
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "xoverlay.h"

enum
{
  HAVE_XWINDOW_ID,
  DESIRED_SIZE,
  LAST_SIGNAL
};

static guint gst_x_overlay_signals[LAST_SIGNAL] = { 0 };

static void gst_x_overlay_base_init (gpointer g_class);

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;
}

/* FIXME: evil hack, we should figure out our marshal handling in this interfaces some day */
extern void gst_marshal_VOID__INT_INT (GClosure * closure,
    GValue * return_value, guint n_param_values, const GValue * param_values,
    gpointer invocation_hint, gpointer marshal_data);

static void
gst_x_overlay_base_init (gpointer g_class)
{
  GstXOverlayClass *overlay_class = (GstXOverlayClass *) g_class;
  static gboolean initialized = FALSE;

  if (!initialized) {
    gst_x_overlay_signals[HAVE_XWINDOW_ID] =
        g_signal_new ("have-xwindow-id",
        GST_TYPE_X_OVERLAY, G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GstXOverlayClass, have_xwindow_id),
        NULL, NULL, g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);
    gst_x_overlay_signals[DESIRED_SIZE] =
        g_signal_new ("desired-size-changed",
        GST_TYPE_X_OVERLAY, G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (GstXOverlayClass, desired_size),
        NULL, NULL,
        gst_marshal_VOID__INT_INT, G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);

    initialized = TRUE;
  }

  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.
 */
void
gst_x_overlay_set_xwindow_id (GstXOverlay * overlay, gulong xwindow_id)
{
  GstXOverlayClass *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 fire an have_xwindow_id signal.
 *
 * This function should be used by video overlay developpers.
 */
void
gst_x_overlay_got_xwindow_id (GstXOverlay * overlay, gulong xwindow_id)
{
  g_return_if_fail (overlay != NULL);
  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  g_signal_emit (G_OBJECT (overlay),
      gst_x_overlay_signals[HAVE_XWINDOW_ID], 0, (gint) xwindow_id);
}

/**
 * gst_x_overlay_get_desired_size:
 * @overlay: a #GstXOverlay which got a XWindow.
 * @width: pointer to a gint taking the width or NULL.
 * @height: pointer to a gint taking the height or NULL.
 *
 * Gets the desired size of the overlay. If the overlay doesn't know its desired
 * size, width and height are set to 0.
 */
void
gst_x_overlay_get_desired_size (GstXOverlay * overlay, guint * width,
    guint * height)
{
  guint width_tmp, height_tmp;
  GstXOverlayClass *klass;

  g_return_if_fail (G_TYPE_CHECK_INSTANCE_TYPE ((overlay), GST_TYPE_X_OVERLAY));

  klass = GST_X_OVERLAY_GET_CLASS (overlay);
  if (klass->get_desired_size && GST_IS_X_OVERLAY (overlay)) {
    /* this ensures that elements don't need to check width and height for NULL 
       but apps may use NULL */
    klass->get_desired_size (overlay, width ? width : &width_tmp,
        height ? height : &height_tmp);
  } else {
    if (width)
      *width = 0;
    if (height)
      *height = 0;
  }
}

/**
 * gst_x_overlay_got_desired_size:
 * @overlay: a #GstXOverlay which changed its desired size.
 * @width: The new desired width
 * @height: The new desired height
 *
 * This will fire a "desired_size_changed" signal.
 *
 * This function should be used by video overlay developpers.
 */
void
gst_x_overlay_got_desired_size (GstXOverlay * overlay, guint width,
    guint height)
{
  g_return_if_fail (GST_IS_X_OVERLAY (overlay));

  g_signal_emit (G_OBJECT (overlay),
      gst_x_overlay_signals[DESIRED_SIZE], 0, width, height);
}

/**
 * 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.
 */
void
gst_x_overlay_expose (GstXOverlay * overlay)
{
  GstXOverlayClass *klass = GST_X_OVERLAY_GET_CLASS (overlay);

  if (klass->expose) {
    klass->expose (overlay);
  }
}