/* 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);
}
}