Is it possible to find a widget's Layout which add it?

[HiJack]

I really doubt that you can do it. It it just not the business of widgets to know how and by whom they are layouted.

There might be a dirty way. When you add a widget to a layout it gets reparented. You might want to check the parent.
But I have no idea what happens when you have complicated layout hierachies.

yes, i misunderstood this. For me, it is amazing that two layouts can add same child widget, though only one position which added could be shown at the same time. In this case, it make no sense to check the only layout. we can test that, it paints ambiguously when i resize the main window from left to right. But i 'm still confused. there got to be some api at least? A list contain the layouts? or something else.