[DllImport("libgstreamer-0.10.dll") ]
static extern bool gst_bin_add (IntPtr raw, IntPtr element);

[DllImport ("libgobject-2.0-0.dll") ]
static extern IntPtr g_object_ref (IntPtr raw);

public bool Add (Gst.Element element) {
  bool raw_ret = gst_bin_add (Handle, element == null ? IntPtr.Zero : element.Handle);
  if (raw_ret) {
    // Incrmenting the refcount of the element.
    g_object_ref (element.Handle);
  }
  bool ret = raw_ret;
  return ret;
}

public bool Add (params Element[] elements) {
  if (elements == null) {
    return false;
  }

  foreach (Element element in elements) {
    if (element == null || !Add (element)) {
      return false;
    }
  }

  return true;
}

public bool Remove (params Element[] elements) {
  if (elements == null) {
    return false;
  }

  foreach (Element element in elements) {
    if (element == null || !Remove (element)) {
      return false;
    }
  }

  return true;
}

public Gst.Element GetByInterface (System.Type type) {
  if (!type.IsSubclassOf (typeof (GLib.GInterfaceAdapter)))
    return null;

  GLib.GType t = (GLib.GType) type;

  return GetByInterface (t);
}

[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_elements (IntPtr bin);
[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_recurse (IntPtr bin);
[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_sinks (IntPtr bin);
[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_sorted (IntPtr bin);
[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_sources (IntPtr bin);
[DllImport("libgstreamer-0.10.dll") ]
static extern IntPtr gst_bin_iterate_all_by_interface (IntPtr bin, IntPtr gtype);

public IEnumerable Elements {
  get {
    return new Enumerable (gst_bin_iterate_elements (Handle));
  }
}

public IEnumerable ElementsRecurse {
  get {
    return new Enumerable (gst_bin_iterate_recurse (Handle));
  }
}

public IEnumerable ElementsSorted {
  get {
    return new Enumerable (gst_bin_iterate_sorted (Handle));
  }
}

public IEnumerable SinkElements {
  get {
    return new Enumerable (gst_bin_iterate_sinks (Handle));
  }
}

public IEnumerable SourceElements {
  get {
    return new Enumerable (gst_bin_iterate_sources (Handle));
  }
}

public IEnumerable GetAllByInterface (GLib.GType type) {
  return new Enumerable (gst_bin_iterate_all_by_interface (Handle, type.Val));
}

public IEnumerable GetAllByInterface (System.Type type) {
  if (!type.IsSubclassOf (typeof (GLib.GInterfaceAdapter)))
    return null;

  GLib.GType t = (GLib.GType) type;

  return GetAllByInterface (t);
}