Hello,
technically seen, at the runtime all GUI components build a kind of view tree (see Understand the view tree and the Owner relationships). The Owner variable of a GUI component refers in this case its superior component this component is nested inside (we could say: Owner is the parent of the component). Owner.Owner addresses consequently the next superior component (let's say: the grandparent).
The property Focus, in turn, controls the so-called focus path (see Keyboard events and the focus path). It is used to determine the actual selection within a GUI component and to dispatch the keyboard events along this path.
The operation Owner.Owner.Focus = Owner modifies the property Focus of the 'grandparent' component assigning to it the parent component. The grandparent component refers thus the parent component of the actual component. In this way the parent component is selected (focused) within the grandparent component.
Does it help you further?
Best regards
Paul Banach
