The widget to activate when the row is activated.
The row can be activated either by clicking on it, calling adw.action_row.ActionRow.activate, or via mnemonics in the title. See the property@PreferencesRow:use-underline property to enable mnemonics.
The target widget will be activated by emitting the signal@Gtk.Widget::mnemonic-activate signal on it.
Builder instance for fluent chaining
Set activatableWidget property.