gdk:window-children-with-user-data (window data)

window -- a gdk:window object
data -- user data to look for as a pointer

list of gdk:window child windows inside window

Gets the list of children of the window known to GDK with a particular data set on it. The returned list must be freed, but the elements in the list need not be.

The list is returned in (relative) stacking order, i.e. the lowest window is first.