Wrong TextEdit::contentWidth

import QtQuick 2.1

Item {
    width: 320
    height: 240

    Flickable {
        id: flickable
        anchors.fill: parent

        TextEdit {
            id: edit
            wrapMode: TextEdit.WordWrap
            text: new Array(256).join("adgadg adgadg gda gd dgadg dgaadgadg")

            width: flickable.width
            height: flickable.height

            // observe the blue rect indicating TextEdit's content size
            Rectangle {
                width: edit.contentWidth
                height: edit.contentHeight
                color: "blue"; opacity: 0.2
            }
        }
    }
}