cascading size callbacks

[Paul Davis <pbd Op Net>]

lets suppose i use a fixed or a layout widget to put children
inside. i want the position of the children to be based on a
fractional coordinate system (0..1.0). this means that when the parent
changes size, i need to move the children.

it seemed to me that the obvious thing to do was to use the
size_allocate signal to drive the repositioning of the children. so i
tried it. it ends up causing a cascade of size_allocate events that
ripple all the way to the top level window on a repeated basis?

why? because using gtk_layout_move() or gtk_fixed_moved() to
reposition the child in turn causes a gtk_widget_queue_resize() on the
child, which by my understanding propagates up to the parent and
beyond. 

what would be the right way (other than using the canvas) to
accomplish this?

--p