Cannot Use A Sub Element ?

[moolight-seashell]

i try to make an app footer with inner logic and mutiple footer screen,in the end i only have a black footer?
There is a summary of my code, so what did I forget ?

The caller (in another file) :

The result (same in preview or build)

so why my component has a size of 0?

[moolight-seashell]

hmm ok i've understand it's because here i d'ont have layout so no automatic streching

i need to add this width: parent.width; height: parent.height;