How get size from widget (Panel)?

Hello everybody,

I would like to create a customize widget with several components for my HomeMatic heating controller. My first problem is that the knob does not adjust to the size of it panels from the widget. I know that in the ng-init = “knob” with size the size itself can change but how can I get the size of the widget queried? {{itemValue (widget.size)}} or {{itemState (widget.size)}} do not work.

Best regards,
Björn