Dancing with a layout applied to a Widget (1 widget +1 float widget)

My form ( a widget form - without central widget) has 1 frame and a custom widget with moving capabilities.

The frame has an internal grid layout to place the inner widgets. Ok.

I place this widget into a new dialog (at run time) or inside another widget (at design time) , and I'd want the widget to autoadjust to the available size .

I have not central widget into my form-widget.(because it is a widget, not a dlialog)

As a rule, to have autoadjust capabilities, you select your widget (or central widget) and choose a general layout, inst't it ? But I cant do this becasue I want to let my float widget out of the layout.

I already asked in the past about this question, but keep with the same problem.
So please.... I need help. Thanks.