If you call focus_set(m, o) where o is a logical child, then the focus
will go to any none logical child of o, or if there is nothing in the
children of o, then the focus will remain on the now focused element.
it turns out to be very handy to have a interface for the moving and
border elements, that is unconnected to the way of how widgets are
registering themself.
This for example enables us to get a simple focus manager that just
redirects the call into a internal 2 dimensional data struct
The Efl.Ui.Focus.Manager abstracts the creation of a localization graph
and a logical tree. The localization graph is used to find a object
right left up or down of a given object. The logical tree is used to
iterate throuw the containers which are used to build a ui.
Those managers can be used bound to some layer in the ui, so for
example the window is a layer, the content of a scroller is a layer.
With those layers, we can make sure that movements of a scroller for
example just means that this graph of objects in the scroller needs to
be recalculated, and not the complete ui.
The advantage of having this to layer bound datastructures is that you
can easily debug those graphs, since the complete layer of this
managerobject can be calculated completly.
Marcel Hollerbach
Carsten Haitzler