Qt Designer: Insert pasted widget as child of selected

When a layout is both a child of another layout and without any children, it generally will have either zero width or zero height. As such, attempting to insert a widget as child by drag-and-drop generally will be infeasible. Attempts to populate the child layout rather will populate the parent.

In may seem consistent with common patterns that a widget pasted from clipboard would be inserted as child of a selected widget, whether the pasting or selection is through the Form Builder or the Object Inspector. However, the pattern is not followed by the application. Pasted widgets rather are inserted at the top level.

Even pasting through the popup menu corresponding to an object represented in the tree in the Object Inspector results simply in the widget inserted at the top level.

Suggested is that a paste operation would insert a widget as a child of the selected one, or of that node from which was generated the popup menu from which the paste action was chosen in the Object Inspector.