GdkWindowget_parent

Obtains the parent of window, as known to GDK. Does not query the X server; thus this returns the parent as passed to gdk_window_new(), not the actual parent. This should never matter unless you’re using Xlib calls mixed with GDK calls on the X11 platform. It may also matter for toplevel windows, because the window manager may choose to reparent them.

Note that you should use gdk_window_get_effective_parent() when writing generic code that walks up a window hierarchy, because gdk_window_get_parent() will most likely not do what you expect if there are offscreen windows in the hierarchy.