components/SubtitledItemDelegate.qml

import QtQuick 2.0
import QtQuick.Controls 2.2

ItemDelegate {
    id: root

    property string subtitle: ""

    contentItem: Column {
        Label {
            id: titleLabel

            width: parent.width
            text: root.text
        }

        Label {
            width: parent.width
            font.pixelSize: titleLabel.font.pixelSize - 2
            text: root.subtitle
            opacity: 0.8
        }
    }
}