Dynamic button

TabBar {
    id: bar
    contentHeight: 30
    width: parent.width

    Repeater {
        model: buttonModel

        TabButton {
            text: model + " " + model.index
            width: Math.max(100, bar.width / 5)
        }
    }
}

ListModel { id: buttonModel }

Button {
    text: "ADD"
    onClicked: buttonModel.append({text: "Test button"})
}