+/**
+ * glk_window_set_echo_stream:
+ * @win: A window.
+ * @str: A stream to attach to the window, or #NULL.
+ *
+ * Attaches the stream @str to @win as a second stream. Any text printed to the
+ * window is also echoed to this second stream, which is called the window's
+ * "echo stream."
+ *
+ * Effectively, any call to glk_put_char() (or the other output commands) which
+ * is directed to @win's window stream, is replicated to @win's echo stream.
+ * This also goes for the style commands such as glk_set_style().
+ *
+ * Note that the echoing is one-way. You can still print text directly to the
+ * echo stream, and it will go wherever the stream is bound, but it does not
+ * back up and appear in the window.
+ *
+ * It is illegal to set a window's echo stream to be its own window stream,
+ * which would create an infinite loop. It is similarly illegal to create a
+ * longer loop (two or more windows echoing to each other.)
+ *
+ * You can reset a window to stop echoing by setting @str to #NULL.
+ */
+void
+glk_window_set_echo_stream(winid_t win, strid_t str)
+{
+ g_return_if_fail(win != NULL);
+
+ /* Test for an infinite loop */
+ strid_t next_str;
+ for(next_str = str;
+ next_str != NULL && next_str->stream_type == STREAM_TYPE_WINDOW;
+ next_str = next_str->window->echo_stream)
+ {
+ if(next_str == win->window_stream)
+ {
+ g_warning("glk_window_set_echo_stream: Infinite loop detected");
+ win->echo_stream = NULL;
+ return;
+ }
+ }
+
+ win->echo_stream = str;
+}
+
+/**
+ * glk_window_get_echo_stream:
+ * @win: A window.
+ *
+ * Returns the echo stream of window @win. If the window has no echo stream (as
+ * is initially the case) then this returns #NULL.
+ *
+ * Returns: A stream, or #NULL.
+ */
+strid_t
+glk_window_get_echo_stream(winid_t win)
+{
+ g_return_val_if_fail(win != NULL, NULL);
+ return win->echo_stream;
+}
+
+void
+glk_window_get_size(winid_t win, glui32 *widthptr, glui32 *heightptr)
+{
+ g_return_if_fail(win != NULL);
+
+ if(widthptr != NULL) {
+ *widthptr = 0;
+ }
+
+ if(heightptr != NULL) {
+ *heightptr = 0;
+ }
+}
+
+void
+glk_window_move_cursor(winid_t win, glui32 xpos, glui32 ypos)
+{
+ g_return_if_fail(win != NULL);
+}