GtkEventBox::set_above_child
You may use this method if you wish to position your event box above the window of its child, as opposed to below it. As mentioned before, if the window is above, all events received inside the event box will go to the event box itself. However is the window is positioned below, events in the window of the child will first go to that widget and then to its parents.
The default keeps the window below the child. You may pass true as a parameter to this method to position the window above the child.
See also: get_above_child()