TableView header for Qt Quick Controls does not follow horizontalAlignment option.

TableView {
    anchors.fill: parent
    TableViewColumn{ role: "title"; title: "Title"; horizontalAlignment: Text.AlignHCenter; width: 320 }
    TableViewColumn{ role: "author"; title: "Author"; horizontalAlignment: Text.AlignHCenter; width: 320 }
    model: libraryModel
}

TableView {
    anchors.fill: parent
    TableViewColumn{ role: "title"; title: "Title"; horizontalAlignment: Text.AlignHCenter; width: 320 }
    TableViewColumn{ role: "author"; title: "Author"; horizontalAlignment: Text.AlignHCenter; width: 320 }
    model: libraryModel
    headerDelegate: Item {
        height: 20
        clip: true
        Rectangle {
            anchors.fill: parent
            anchors.leftMargin: -1
            anchors.topMargin: -1
            gradient: Gradient {
                GradientStop { color: "#eee" ; position: 0 }
                GradientStop { color: "#ccc" ; position: 1 }
            }
            border.color: "#aaa"
        }
        Text {
            anchors.fill: parent
            horizontalAlignment: Text.AlignHCenter
            verticalAlignment: Text.AlignVCenter
            text: styleData.value
            elide: Text.ElideMiddle
            renderType: Text.NativeRendering
        }
    }
}