Yes, I know I am re-inventing the wheel, but I thought this would be an interesting exercise for teaching myself C under Ubuntu Linux and Gnome.

I want a black background against which the .jpg images will be shown. I also want the screensaver to respond to keyboard events so that it can do various things depending on which key is pressed.

The only way I have discovered of getting a completely black background is with a GTK_WINDOW_POPUP, which is displayed independently of the window manager and so hides the Gnome top & bottom panels.

I then use a GTK_WINDOW_TOPLEVEL with gtk_window_set_decorated = FALSE to display the images without borders.

This second window sucessfully receives keyboard events ... but is unfortunately invisible, presumably because the window manager displays it under the black GTK_WINDOW_POPUP. I have tried various things to get the desired result, but without success.

Can anyone suggest a method of achieving my aim? I would prefer to work at the GTK / GDK levels rather than at the Xwindow level.

Code follows:

/* Declare widgets etc.
-----------------------*/

/* black background window */
GtkWindow *window_bg;
GdkPixbuf *pixbuf_bg;
GtkWidget *picture_bg;

/* image display window */
GtkWindow *window;
GdkPixbuf *pixbuf;
GtkWidget *picture;


int main(int argc, char **argv)
{
/* Initialise GTK+ */
gtk_init(&argc, &argv);

/* ***** Create & display black background *******/
window_bg = GTK_WINDOW(gtk_window_new(GTK_WINDOW_POPUP));
pixbuf_bg = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
FALSE, 8, 1280, 1024); /* default black pixbuf */

picture_bg=gtk_image_new_from_pixbuf(pixbuf_bg);
gtk_container_add(GTK_CONTAINER(window_bg), GTK_WIDGET(picture_bg));
gtk_widget_show_all(GTK_WIDGET(window_bg));

/* ***** Create photo display ******/
window = GTK_WINDOW(gtk_window_new(GTK_WINDOW_TOPLEVEL));
pixbuf = gdk_pixbuf_new_from_file_at_scale("test.jpg", 1280, 1024, TRUE, NULL);
picture=gtk_image_new_from_pixbuf(pixbuf);

/* signal handlers would be here */

/* pack the image into the window & display */
gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(picture));
gtk_widget_show_all(GTK_WIDGET(window));

/* Set window to have no border etc. */
gtk_window_set_decorated(window, FALSE);

/* Start main event loop */
gtk_main();

return 0;
}