gstreamer/gst-libs/gst/vaapi/gstvaapiutils_x11.c

/*
 *  gstvaapiutils_x11.c - X11 utilties
 *
 *  Copyright (C) 2010-2011 Splitted-Desktop Systems
 *    Author: Gwenole Beauchesne <gwenole.beauchesne@splitted-desktop.com>
 *  Copyright (C) 2011-2013 Intel Corporation
 *    Author: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1
 *  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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

#include "sysdeps.h"
#include <glib.h>
#include <X11/Xutil.h>
#include "gstvaapiutils_x11.h"

// X error trap
static int x11_error_code = 0;
static int (*old_error_handler) (Display *, XErrorEvent *);

static int
error_handler (Display * dpy, XErrorEvent * error)
{
  x11_error_code = error->error_code;
  return 0;
}

void
x11_trap_errors (void)
{
  x11_error_code = 0;
  old_error_handler = XSetErrorHandler (error_handler);
}

int
x11_untrap_errors (void)
{
  XSetErrorHandler (old_error_handler);
  return x11_error_code;
}

// X window management
static const int x11_event_mask = (KeyPressMask | KeyReleaseMask
    | ButtonPressMask | ButtonReleaseMask | PointerMotionMask
    | EnterWindowMask | ExposureMask | StructureNotifyMask);

/**
 * x11_create_window:
 * @dpy: an X11 #Display
 * @w: the requested width, in pixels
 * @h: the requested height, in pixels
 * @vid: the requested visual id
 * @cmap: the requested colormap
 *
 * Creates a border-less window with the specified dimensions. If @vid
 * is zero, the default visual for @display will be used. If @cmap is
 * %None, no specific colormap will be bound to the window. Also note
 * the default background color is black.
 *
 * Return value: the newly created X Window.
 */
Window
x11_create_window (Display * dpy, guint w, guint h, guint vid, Colormap cmap)
{
  Window rootwin, win;
  int screen, depth;
  XSetWindowAttributes xswa;
  unsigned long xswa_mask;
  XWindowAttributes wattr;
  unsigned long black_pixel;
  XVisualInfo visualInfo, *vi;
  int num_visuals;

  screen = DefaultScreen (dpy);
  rootwin = RootWindow (dpy, screen);
  black_pixel = BlackPixel (dpy, screen);

  XGetWindowAttributes (dpy, rootwin, &wattr);
  depth = wattr.depth;
  if (depth != 15 && depth != 16 && depth != 24 && depth != 30 && depth != 32)
    depth = 24;

  xswa_mask = CWBorderPixel | CWBackPixel;
  xswa.border_pixel = black_pixel;
  xswa.background_pixel = black_pixel;

  if (cmap) {
    xswa_mask |= CWColormap;
    xswa.colormap = cmap;
  }

  if (vid) {
    visualInfo.visualid = vid;
    vi = XGetVisualInfo (dpy, VisualIDMask, &visualInfo, &num_visuals);
    if (!vi || num_visuals < 1)
      goto error_create_visual;
  } else {
    vi = &visualInfo;
    XMatchVisualInfo (dpy, screen, depth, TrueColor, vi);
  }

  win = XCreateWindow (dpy, rootwin, 0, 0, w, h, 0, depth, InputOutput,
      vi->visual, xswa_mask, &xswa);
  if (vi != &visualInfo)
    XFree (vi);
  if (!win)
    goto error_create_window;

  XSelectInput (dpy, win, x11_event_mask);
  return win;

  /* ERRORS */
error_create_visual:
  GST_ERROR ("failed to create X visual (id:%zu)", (gsize) visualInfo.visualid);
  if (vi)
    XFree (vi);
  return None;
error_create_window:
  GST_ERROR ("failed to create X window of size %ux%u", w, h);
  return None;
}

gboolean
x11_get_geometry (Display * dpy, Drawable drawable, gint * px, gint * py,
    guint * pwidth, guint * pheight, guint * pdepth)
{
  Window rootwin;
  int x, y;
  guint width, height, border_width, depth;

  x11_trap_errors ();
  XGetGeometry (dpy, drawable, &rootwin, &x, &y, &width, &height,
      &border_width, &depth);
  if (x11_untrap_errors ())
    return FALSE;

  if (px)
    *px = x;
  if (py)
    *py = y;
  if (pwidth)
    *pwidth = width;
  if (pheight)
    *pheight = height;
  if (pdepth)
    *pdepth = depth;
  return TRUE;
}