I refactored the tab bar used in Piepmatz and Wunderfitz into a stand-alone component. Maybe you would like to use it as long as Silica’s TabBar is still a private component? You can find the code here: https://github.com/ichthyosaurus/sf-docked-tab-bar
(I didn’t have the time for proper documentation yet. You can see here how to use it: https://github.com/ichthyosaurus/harbour-wunderfitz/blob/some-refactoring/qml/harbour-wunderfitz.qml and …/pages/TitlePage.qml)