Some interface implementations for video4linux/video4linux2 plugins: a Tuner interface, with which one can select inp...

Original commit message from CVS:
Some interface implementations for video4linux/video4linux2 plugins:
* a Tuner interface, with which one can select inputs and stations. Audio
work is underway here, but unfinished.
* A Xoverlay interface with which one can do simple overlay. Similar to
the API of the v4l/Xv XFree86 extension. Widget implementation for
GTK-2.0 coming up in the sandbox.
* Colorbalance - for adapting colors (brightness, contrast, etc.) - pretty
basic and maybe somewhat overdesigned. But it'll do for now.

Apart from these interfaces, there's also a loadable library 'xwindowlistener'
that listenes to X for the movement of a window and the overlap of other
windows. This is partly copied from xawtv (and thus partly GPL :(), but it's
needed for the xoverlay interface implementation in the v4l/v4l2 elements.

Lastly, some small changes to remove redundant properties from the v4l/v4l2
elements since these can be done much simpler. Comments appreciated!

3 files changed, 783 insertions, 0 deletions

diff --git a/gst-libs/gst/xwindowlistener/Makefile.am b/gst-libs/gst/xwindowlistener/Makefile.am
new file mode 100644
index 00000000..a3a589ba
--- /dev/null
+++ b/gst-libs/gst/xwindowlistener/Makefile.am
@@ -0,0 +1,11 @@
+librarydir = $(libdir)/gstreamer-@GST_MAJORMINOR@
+
+library_LTLIBRARIES = libgstxwindowlistener.la
+
+libgstxwindowlistener_la_SOURCES = xwindowlistener.c
+
+libraryincludedir = $(includedir)/gstreamer-@GST_MAJORMINOR@/gst/xwindowlistener
+libraryinclude_HEADERS = xwindowlistener.h
+
+libgstxwindowlistener_la_CFLAGS = $(GST_CFLAGS) $(X_CFLAGS)
+libgstxwindowlistener_la_LIBADD = $(GST_LIBS) $(GST_PLUGIN_LIBS) $(X_LIBS)
diff --git a/gst-libs/gst/xwindowlistener/xwindowlistener.c b/gst-libs/gst/xwindowlistener/xwindowlistener.c
new file mode 100644
index 00000000..0a400a53
--- /dev/null
+++ b/gst-libs/gst/xwindowlistener/xwindowlistener.c
@@ -0,0 +1,656 @@
+/* G-Streamer X11 Window event/motion listener
+ * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ *
+ * xwindowlistener.c: implementation of the object
+ *
+ * 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 <gst/gst.h>
+#include "xwindowlistener.h"
+
+#define NUM_CLIPS 1024
+
+static void gst_x_window_listener_class_init (GstXWindowListenerClass *klass);
+static void gst_x_window_listener_init       (GstXWindowListener *xwin);
+static void gst_x_window_listener_dispose    (GObject            *object);
+
+static void gst_xwin_start		     (GstXWindowListener *xwin);
+static void gst_xwin_stop		     (GstXWindowListener *xwin);
+
+static GObjectClass *parent_class = NULL;
+
+GType
+gst_x_window_listener_get_type (void)
+{
+  static GType x_window_listener_type = 0;
+
+  if (!x_window_listener_type) {
+    static const GTypeInfo x_window_listener_info = {
+      sizeof (GstXWindowListenerClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) gst_x_window_listener_class_init,
+      NULL,
+      NULL,
+      sizeof (GstXWindowListener),
+      0,
+      (GInstanceInitFunc) gst_x_window_listener_init,
+      NULL
+    };
+
+    x_window_listener_type =
+	g_type_register_static (G_TYPE_OBJECT,
+				"GstXWindowListener",
+				&x_window_listener_info, 0);
+  }
+
+  return x_window_listener_type;
+}
+
+static void
+gst_x_window_listener_class_init (GstXWindowListenerClass *klass)
+{
+  GObjectClass *object_klass = (GObjectClass *) klass;
+
+  parent_class = g_type_class_ref (G_TYPE_OBJECT);
+
+  object_klass->dispose = gst_x_window_listener_dispose;
+}
+
+static void
+gst_x_window_listener_init (GstXWindowListener *xwin)
+{
+  xwin->xwindow_id = 0;
+  xwin->display_name = NULL;
+
+  xwin->map_window_func = NULL;
+  xwin->set_window_func = NULL;
+
+  xwin->thread = NULL;
+}
+
+static void
+gst_x_window_listener_dispose (GObject *object)
+{
+  GstXWindowListener *xwin = GST_X_WINDOW_LISTENER (object);
+
+  /* stop overlay */
+  gst_x_window_listener_set_xid (xwin, 0);
+
+  if (xwin->display_name) {
+    g_free (xwin->display_name);
+  }
+
+  if (parent_class->dispose) {
+    parent_class->dispose (object);
+  }
+}
+
+GstXWindowListener *
+gst_x_window_listener_new (gchar           *display,
+			   MapWindowFunc    map_window_func,
+			   SetWindowFunc    set_window_func,
+			   gpointer         private_data)
+{
+  GstXWindowListener *xwin =
+	g_object_new (GST_TYPE_X_WINDOW_LISTENER, NULL);
+
+  xwin->display_name = g_strdup (display);
+  xwin->map_window_func = map_window_func;
+  xwin->set_window_func = set_window_func;
+  xwin->private_data = private_data;
+
+  return xwin;
+}
+
+void
+gst_x_window_listener_set_xid (GstXWindowListener *xwin,
+			       XID                 id)
+{
+  g_return_if_fail (xwin != NULL);
+
+  if (id == xwin->xwindow_id) {
+    return;
+  }
+
+  if (xwin->xwindow_id && xwin->thread) {
+    gst_xwin_stop (xwin);
+  }
+
+  xwin->xwindow_id = id;
+
+  if (xwin->xwindow_id &&
+      xwin->display_name &&
+      xwin->display_name[0] == ':') {
+    g_return_if_fail (xwin->map_window_func != NULL);
+    g_return_if_fail (xwin->set_window_func != NULL);
+
+    gst_xwin_start (xwin);
+  }
+}
+
+/*
+ * The following code works as follows:
+ *  - the "client" (the one who uses this object) sets an XID
+ *  - we add a child XWindow to this XID, and follow motion/events
+ *  - after each event, we determine the position, size and clips
+ *  - next, we call the per-instance virtual functions set by the client
+ *  - and we do all this in an endless cycle
+ *
+ * Unfortunately, part of this code is inspired by XawTV, so the
+ * runtime license for this code as a whole will be GPL unless
+ * someone can rewrite this or ask permission to the original
+ * author (Gerd Knorr <kraxel@bytesex.org>) to let us re-license
+ * this piece of code to LGPL.
+ */
+
+#define DEBUG(format, args...) \
+  GST_DEBUG ("XWL: " format, ##args)
+
+static void
+gst_xwin_set_overlay (GstXWindowListener *xwin,
+		      gboolean       on)
+{
+  xwin->map_window_func (xwin->private_data, on);
+
+  /* remember me */
+  xwin->ov_visible = on;
+}
+
+static gboolean
+gst_xwin_refresh (gpointer data)
+{
+  GstXWindowListener *xwin = GST_X_WINDOW_LISTENER (data);
+  Window win, tmp;
+  XSetWindowAttributes xswa;
+  XWindowAttributes attr;
+
+  g_mutex_lock (xwin->main_lock);
+
+  win = DefaultRootWindow (xwin->main_display);
+  XGetWindowAttributes (xwin->main_display, win, &attr);
+
+  xwin->ov_refresh_id = 0;
+
+  if (!xwin->ov_move && xwin->ov_map &&
+      xwin->ov_visibility == VisibilityUnobscured) {
+    g_mutex_unlock (xwin->main_lock);
+    return FALSE; /* skip */
+  }
+
+  if (xwin->ov_map &&
+      xwin->ov_visibility != VisibilityFullyObscured) {
+    xwin->ov_refresh = TRUE;
+  }
+
+  xswa.override_redirect = True;
+  xswa.backing_store = NotUseful;
+  xswa.save_under = False;
+  tmp = XCreateWindow (xwin->main_display,win, 0, 0,
+		       attr.width, attr.height, 0,
+		       CopyFromParent, InputOutput, CopyFromParent,
+		       (CWSaveUnder | CWBackingStore| CWOverrideRedirect ),
+		       &xswa);
+  XMapWindow (xwin->main_display, tmp);
+  XUnmapWindow (xwin->main_display, tmp);
+  XDestroyWindow (xwin->main_display, tmp);
+  xwin->ov_move = FALSE;
+
+  g_mutex_unlock (xwin->main_lock);
+
+  /* once */
+  return FALSE;
+}
+
+static int
+x11_error_dev_null (Display     *display,
+		    XErrorEvent *event)
+{
+    return 0;
+}
+
+#define ADD_CLIP(_x, _y, _w, _h) \
+  do { \
+    GstXWindowClip *clip = &xwin->clips[xwin->num_clips++]; \
+    clip->x_offset = _x; \
+    clip->y_offset = _y; \
+    clip->width = _w; \
+    clip->height = _h; \
+    clip->data = NULL; \
+  } while (0);
+
+static void
+gst_xwin_set_clips (GstXWindowListener *xwin)
+{
+  Window root, rroot, parent, *kids, me;
+  XWindowAttributes attr;
+  guint numkids;
+  gint i;
+  gint x1, y1, w1, h1;
+  void *old_handler;
+
+  old_handler = XSetErrorHandler (x11_error_dev_null);
+
+  if (xwin->num_clips != 0)
+    xwin->ov_conf = TRUE;
+  xwin->num_clips = 0;
+
+  root = DefaultRootWindow (xwin->display);
+  XGetWindowAttributes (xwin->display, root, &attr);
+
+  if (xwin->x < 0)
+    ADD_CLIP (0, 0, -xwin->x, xwin->h);
+  if (xwin->y < 0)
+    ADD_CLIP (0, 0, xwin->w, -xwin->y);
+  if ((xwin->x + xwin->w) > attr.width)
+    ADD_CLIP (attr.width - xwin->x, 0, xwin->w, xwin->h);
+  if ((xwin->y + xwin->h) > attr.height)
+    ADD_CLIP (0, attr.height - xwin->y, xwin->w, xwin->h);
+
+  me = xwin->child;
+  while (1) {
+    XQueryTree (xwin->display, me, &rroot, &parent, &kids, &numkids);
+    if (numkids)
+      XFree (kids);
+    if (root == parent)
+      break;
+    me = parent;
+  }
+
+  XQueryTree (xwin->display, root, &rroot, &parent, &kids, &numkids);
+  for (i = 0; i < numkids; i++)
+    if (kids[i] == me)
+      break;
+
+  for (i++; i < numkids; i++) {
+    XGetWindowAttributes (xwin->display, kids[i], &attr);
+    if (attr.map_state != IsViewable)
+      continue;
+
+    x1 = attr.x - xwin->x;
+    y1 = attr.y - xwin->y;
+    w1 = attr.width + 2 * attr.border_width;
+    h1 = attr.height + 2 * attr.border_width;
+    if (((x1 + w1) < 0) || (x1 > xwin->w) ||
+        ((y1 + h1) < 0) || (y1 > xwin->h))
+      continue;
+	
+    if (x1 < 0)
+      x1 = 0;
+    if (y1 < 0)
+      y1 = 0;
+    ADD_CLIP (x1, y1, w1, h1);
+  }
+  XFree (kids);
+
+  if (xwin->num_clips != 0)
+    xwin->ov_conf = TRUE;
+
+  XSetErrorHandler (old_handler);
+}
+
+
+static gboolean
+gst_xwin_window (GstXWindowListener *xwin)
+{
+  if (xwin->ov_map && xwin->ov_wmmap &&
+      xwin->ov_visibility != VisibilityFullyObscured) {
+    /* visible */
+    if (xwin->ov_visibility == VisibilityPartiallyObscured) {
+      /* set clips */
+      gst_xwin_set_clips (xwin);
+    }
+
+    if (xwin->ov_conf) {
+      xwin->set_window_func (xwin->private_data,
+			     xwin->x, xwin->y,
+			     xwin->w, xwin->h,
+			     xwin->clips, xwin->num_clips);
+
+      if (!xwin->ov_visible)
+        gst_xwin_set_overlay (xwin, TRUE);
+
+      g_mutex_lock (xwin->main_lock);
+
+      if (xwin->ov_refresh_id)
+        g_source_remove (xwin->ov_refresh_id);
+      xwin->ov_refresh_id =
+	  g_timeout_add (200, (GSourceFunc) gst_xwin_refresh,
+			 (gpointer) xwin);
+
+      xwin->ov_conf = FALSE;
+
+      g_mutex_unlock (xwin->main_lock);
+    }
+  } else {
+    /* not visible */
+    if (xwin->ov_conf && xwin->ov_visible) {
+      gst_xwin_set_overlay (xwin, FALSE);
+
+      g_mutex_lock (xwin->main_lock);
+
+      if (xwin->ov_refresh_id)
+        g_source_remove (xwin->ov_refresh_id);
+      xwin->ov_refresh_id =
+	  g_timeout_add (200, (GSourceFunc) gst_xwin_refresh,
+			 (gpointer) xwin);
+
+      xwin->ov_conf = FALSE;
+
+      g_mutex_unlock (xwin->main_lock);
+    }
+  }
+
+  xwin->ov_conf_id = 0;
+
+  /* once is enough */
+  return FALSE;
+}
+
+static void
+gst_xwin_configure (GstXWindowListener *xwin)
+{
+#if 0
+  /* This part is disabled, because the idle task will be done
+   * in the main thread instead of here. */
+  if (!xwin->ov_conf_id)
+    xwin->ov_conf_id =
+	g_idle_add ((GSourceFunc) gst_rec_xoverlay_window,
+		    (gpointer) xwin);
+#endif
+
+  gst_xwin_window ((gpointer) xwin);
+}
+
+static void
+gst_xwin_resize (GstXWindowListener *xwin)
+{
+  Drawable drawable, parent, *kids, root;
+  guint numkids;
+  XWindowAttributes attr;
+
+  XGetWindowAttributes (xwin->display,
+			xwin->xwindow_id, &attr);
+  XMoveResizeWindow (xwin->display, xwin->child,
+		     0, 0, attr.width, attr.height);
+
+  /* set the video window - the first clip is our own window */
+  xwin->x = 0;
+  xwin->y = 0;
+  xwin->w = attr.width;
+  xwin->h = attr.height;
+
+  drawable = xwin->child;
+  while (1) {
+    XQueryTree (xwin->display, drawable,
+		&root, &parent, &kids, &numkids);
+    if (numkids)
+      XFree(kids);
+    drawable = parent;
+    XGetWindowAttributes (xwin->display, drawable, &attr);
+    xwin->x += attr.x;
+    xwin->y += attr.y;
+    if (parent == attr.root)
+      break;
+  }
+
+  xwin->ov_conf = TRUE;
+  xwin->ov_move = TRUE;
+
+  gst_xwin_configure (xwin);
+}
+
+static void
+gst_xwin_init_window (GstXWindowListener *xwin)
+{
+  XWindowAttributes attr;
+
+  /* start values */
+  xwin->ov_conf = TRUE;
+  xwin->ov_map = xwin->ov_wmmap = TRUE;
+  xwin->ov_move = TRUE;
+  xwin->ov_refresh = FALSE;
+  g_mutex_lock (xwin->main_lock);
+  xwin->ov_conf_id = xwin->ov_refresh_id = 0;
+  g_mutex_unlock (xwin->main_lock);
+  xwin->ov_visibility = VisibilityFullyObscured;
+
+  /* start the memory that we'll use */
+  xwin->clips = g_malloc (sizeof (GstXWindowClip) * NUM_CLIPS);
+  xwin->num_clips = 0;
+
+  /* open connection to X server */
+  xwin->display = XOpenDisplay (xwin->display_name);
+
+  /* window */
+  XGetWindowAttributes (xwin->display,
+			xwin->xwindow_id, &attr);
+  xwin->child = XCreateSimpleWindow (xwin->display,
+				     xwin->xwindow_id, 0, 0,
+				     attr.width, attr.height, 0, 0, 0);
+
+  /* listen to certain X events */
+  XSelectInput (xwin->display, xwin->xwindow_id,
+		StructureNotifyMask);
+  XSelectInput (xwin->display, xwin->child,
+		VisibilityChangeMask | StructureNotifyMask);
+  XSelectInput (xwin->display, DefaultRootWindow (xwin->display),
+		VisibilityChangeMask | StructureNotifyMask |
+		SubstructureNotifyMask);
+
+  /* show */
+  XMapWindow (xwin->display, xwin->child);
+
+  gst_xwin_resize (xwin);
+}
+
+static void
+gst_xwin_exit_window (GstXWindowListener *xwin)
+{
+  /* disable overlay */
+  gst_xwin_set_overlay (xwin, FALSE);
+
+  /* delete idle funcs */
+  if (xwin->ov_conf_id != 0)
+    g_source_remove (xwin->ov_conf_id);
+
+  g_mutex_lock (xwin->main_lock);
+  if (xwin->ov_refresh_id != 0)
+    g_source_remove (xwin->ov_refresh_id);
+  g_mutex_unlock (xwin->main_lock);
+
+  /* get away from X and free mem */
+  XDestroyWindow (xwin->display, xwin->child);
+  XCloseDisplay (xwin->display);
+  g_free (xwin->clips);
+}
+
+static gpointer
+gst_xwin_thread (gpointer data)
+{
+  GstXWindowListener *xwin = GST_X_WINDOW_LISTENER (data);
+  XEvent event;
+
+  /* Hi, I'm GStreamer. What's your name? */
+  gst_xwin_init_window (xwin);
+
+  while (xwin->cycle) {
+    XNextEvent (xwin->display, &event);
+
+    if (!xwin->cycle)
+      break;
+
+    if ((event.type == ConfigureNotify &&
+         event.xconfigure.window == xwin->xwindow_id) ||
+        (event.type == MapNotify &&
+         event.xmap.window == xwin->xwindow_id) ||
+        (event.type == UnmapNotify &&
+         event.xunmap.window == xwin->xwindow_id)) {
+      /* the 'parent' window, i.e. the widget provided by client */
+      switch (event.type) {
+        case MapNotify:
+          xwin->ov_map = TRUE;
+          xwin->ov_conf = TRUE;
+          gst_xwin_configure (xwin);
+          break;
+
+        case UnmapNotify:
+          xwin->ov_map = FALSE;
+          xwin->ov_conf = TRUE;
+          gst_xwin_configure (xwin);
+          break;
+
+        case ConfigureNotify:
+          gst_xwin_resize (xwin);
+          break;
+
+        default:
+          /* nothing */
+          break;
+      }
+    } else if (event.xany.window == xwin->child) {
+      /* our own private window */
+      switch (event.type) {
+        case Expose:
+          if (!event.xexpose.count) {
+            if (xwin->ov_refresh) {
+              xwin->ov_refresh = FALSE;
+            } else {
+              xwin->ov_conf = TRUE;
+              gst_xwin_configure (xwin);
+            }
+          }
+          break;
+
+        case VisibilityNotify:
+          xwin->ov_visibility = event.xvisibility.state;
+          if (xwin->ov_refresh) {
+            if (event.xvisibility.state != VisibilityFullyObscured)
+              xwin->ov_refresh = FALSE;
+          } else {
+            xwin->ov_conf = TRUE;
+            gst_xwin_configure (xwin);
+          }
+          break;
+
+        default:
+          /* nothing */
+          break;
+      }
+    } else {
+      /* root window */
+      switch (event.type) {
+        case MapNotify:
+        case UnmapNotify:
+          /* are we still visible? */
+          if (!xwin->ov_refresh) {
+            XWindowAttributes attr;
+            gboolean on;
+            XGetWindowAttributes (xwin->display,
+				  xwin->xwindow_id, &attr);
+            on = (attr.map_state == IsViewable);
+            xwin->ov_wmmap = on;
+            xwin->ov_conf = TRUE;
+            gst_xwin_configure (xwin);
+          }
+          break;
+
+        case ConfigureNotify:
+          if (!xwin->ov_refresh) {
+            gst_xwin_resize (xwin);
+          }
+          break;
+
+        default:
+          /* nothing */
+          break;
+      }
+    }
+  }
+
+  /* Nice to have met you, see you later */
+  gst_xwin_exit_window (xwin);
+
+  g_thread_exit (NULL);
+
+  return NULL;
+}
+
+static void
+gst_xwin_start (GstXWindowListener *xwin)
+{
+  DEBUG ("Starting XWindow listener");
+
+  xwin->cycle = TRUE;
+  /* we use this main_display for two things: first of all,
+   * the window needs to be 'refreshed' to remove artifacts
+   * after every move. Secondly, we use this to 'unhang' the
+   * event handler after we've stopped it */
+  xwin->main_lock = g_mutex_new ();
+  xwin->main_display = XOpenDisplay (xwin->display_name);
+  xwin->thread = g_thread_create (gst_xwin_thread,
+					(gpointer) xwin,
+					TRUE, NULL);
+
+  DEBUG ("Started X-overlay");
+}
+
+static void
+gst_xwin_stop (GstXWindowListener *xwin)
+{
+  DEBUG ("Stopping XWindow listener");
+
+  xwin->cycle = FALSE;
+  /* now, the event loop will hang. To prevent this from hanging
+   * our app, app, we re-do our refresh hack. Oh man, this is
+   * ugly. But it works. :). */
+  g_mutex_lock (xwin->main_lock);
+  if (xwin->ov_refresh_id)
+    g_source_remove (xwin->ov_refresh_id);
+  g_mutex_unlock (xwin->main_lock);
+
+  gst_xwin_refresh ((gpointer) xwin);
+  g_thread_join (xwin->thread);
+  XCloseDisplay (xwin->main_display);
+  g_mutex_free (xwin->main_lock);
+
+  DEBUG ("Stopped X-overlay");
+}
+
+/*
+ * End of code inspired by XawTV.
+ */
+
+static gboolean
+plugin_init (GModule   *module,
+	     GstPlugin *plugin)
+{
+  gst_plugin_set_longname (plugin,
+			   "X11-based XWindow event/motion listener");
+  return TRUE;
+}
+
+GstPluginDesc plugin_desc = {
+  GST_VERSION_MAJOR,
+  GST_VERSION_MINOR,
+  "xwindowlistener",
+  plugin_init
+};
diff --git a/gst-libs/gst/xwindowlistener/xwindowlistener.h b/gst-libs/gst/xwindowlistener/xwindowlistener.h
new file mode 100644
index 00000000..834be67c
--- /dev/null
+++ b/gst-libs/gst/xwindowlistener/xwindowlistener.h
@@ -0,0 +1,116 @@
+/* G-Streamer X11 Window event/motion listener
+ * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ *
+ * xwindowlistener.h: object definition
+ *
+ * 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.
+ */
+
+#ifndef __X_WINDOW_LISTENER_H__
+#define __X_WINDOW_LISTENER_H__
+
+#include <gst/gst.h>
+#include <X11/Xlib.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_X_WINDOW_LISTENER \
+  (gst_x_window_listener_get_type())
+#define GST_X_WINDOW_LISTENER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_X_WINDOW_LISTENER, \
+			      GstXWindowListener))
+#define GST_X_WINDOW_LISTENER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_X_WINDOW_LISTENER, \
+			   GstXWindowListenerClass))
+#define GST_IS_X_WINDOW_LISTENER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_X_WINDOW_LISTENER))
+#define GST_IS_X_WINDOW_LISTENER_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_X_WINDOW_LISTENER))
+
+typedef struct _GstXWindowListener	GstXWindowListener;
+typedef struct _GstXWindowListenerClass	GstXWindowListenerClass;
+typedef struct _GstXWindowClip		GstXWindowClip;
+typedef void (* MapWindowFunc)		(gpointer your_data,
+					 gboolean visible);
+typedef void (* SetWindowFunc)		(gpointer your_data,
+					 gint x,  gint y,
+					 gint w,  gint h,
+					 GstXWindowClip *clips,
+					 gint     num_clips);
+
+struct _GstXWindowClip {
+  gint32   x_offset,
+	   y_offset,
+	   width,
+	   height;
+  gpointer data;
+};
+
+struct _GstXWindowListener {
+  GObject  parent;
+
+  /* "per-instance virtual functions" */
+  MapWindowFunc map_window_func;
+  SetWindowFunc set_window_func;
+
+  /* private data with which we call the virtual functions */
+  gpointer private_data;
+
+  /* general information of what we're doing */
+  gchar   *display_name;
+  XID      xwindow_id;
+
+  /* one extra... */
+  Display *main_display;
+  GMutex  *main_lock;
+
+  /* oh my g*d, this is going to be so horribly ugly */
+  GThread *thread;
+  gboolean cycle;
+
+  /* the overlay window + own thread */
+  Display *display;
+  Drawable child;
+  gboolean ov_conf,
+	   ov_map,
+	   ov_visible,
+	   ov_refresh,
+	   ov_move,
+	   ov_wmmap;
+  gint     ov_visibility;
+  guint    ov_conf_id,
+	   ov_refresh_id;
+  gint     x, y, w, h;
+  GstXWindowClip *clips;
+  gint     num_clips;
+};
+
+struct _GstXWindowListenerClass {
+  GObjectClass parent;
+};
+
+GType 	gst_x_window_listener_get_type	(void);
+GstXWindowListener *
+	gst_x_window_listener_new	(gchar              *display,
+					 MapWindowFunc       map_window_func,
+					 SetWindowFunc       set_window_func,
+					 gpointer            private_data);
+void	gst_x_window_listener_set_xid	(GstXWindowListener *xwin,
+					 XID                 id);
+
+G_END_DECLS
+
+#endif /* __X_WINDOW_LISTENER_H__ */