Re: Using gdk_pixbuf_xlib_get_from_drawable()

[Димитров Вячеслав <bordimida mail ru>]

Hi.
In old mail list (2007 year), I saw this problem:

> Hello,


> I have a problem using the function from the subject. I think I'm
> just missing something about how the function works. Here is the
> code (it's just a short program to test the function):

> ### BEGIN CODE ###

> #include <gdk-pixbuf-xlib/gdk-pixbuf-xlib.h>
> #include <gdk/gdkx.h>
> #include <gtk/gtk.h>

> static void
> screenshot (GtkWidget *widget)
> {
>  GdkPixbuf *image;
>  XWindowAttributes wa;
>  Window win;

>  win = GDK_WINDOW_XID (widget->window);
>  XGetWindowAttributes (GDK_DISPLAY(), win, &wa);

>  image = gdk_pixbuf_xlib_get_from_drawable (NULL, 
>                                             win, 0, NULL,
>                                             0, 0, 0, 0,
>                                             wa.width, wa.height);

>  gdk_pixbuf_save (image, "test.png", "png", NULL, NULL);
> }

> intmain (int argc, char *argv[])
> {
>  GtkWidget *window, *button;
>  gtk_init (&argc, &argv);

>  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
>  button = gtk_button_new_with_label ("Hello");

>  g_signal_connect (G_OBJECT (button), "clicked",
                    G_CALLBACK (screenshot), NULL);

>  gtk_container_add (GTK_CONTAINER (window), button);
>  gtk_widget_show_all (window);

>  gtk_main ();
>  return 0;
> }

> ### END CODE ###

> It is crashing in the .._from_drawable() function as you can
> see here:

> Program received signal SIGSEGV, Segmentation fault.
> 0x004943dd in XGetWindowAttributes () from /usr/lib/libX11.so.6
> (gdb) where
> #0  0x004943dd in XGetWindowAttributes () from /usr/lib/libX11.so.6
> #1  0x004651d9 in gdk_pixbuf_xlib_get_from_drawable ()
>   from /usr/lib/libgdk_pixbuf_xlib-2.0.so.0
> #2  0x080488ab in screenshot (widget=0x9caed68) at test.c:36

> I am compiling with:
> gcc -Wall -g test.c -o exe `pkg-config --cflags --libs gtk+-2.0
> gdk-pixbuf-xlib-2.0`

> Thank you for any help you can give me! - Andrew


A work code is representing so:

static void
screenshot (GtkWidget *widget)
{
  GdkPixbuf *image;
  XWindowAttributes wa;
  Window win;

  /*Must init display.*/
  gdk_pixbuf_xlib_init(GDK_DISPLAY(), 0);

  win = GDK_WINDOW_XID (widget->window);
  XGetWindowAttributes (GDK_DISPLAY(), win, &wa);

  image = gdk_pixbuf_xlib_get_from_drawable (NULL,
                                             win, 0, NULL,
                                             0, 0, 0, 0,
                                             wa.width, wa.height);

  gdk_pixbuf_save (image, "test.png", "png", NULL, NULL);
}


With regards Dimitrov Vyacheslav.