ListView: Populate transition on opacity does not work for delegates outside of viewport

import QtQuick 2.3

Item {
    id: root

    width: 300; height: 300

    Component.onCompleted: listView.model = 50

    Item {
        anchors.fill: parent

        ListView {
            id: listView

            anchors.fill: parent
            model: root.itemCount
            delegate: Rectangle {
                color: "lightgray"
                opacity: 0
                width: ListView.view.width; height: 30
                Text {
                    anchors.centerIn: parent
                    text: index
                }
            }
            populate: Transition {
                NumberAnimation { property: "opacity"; to: 1.0; duration: 1000 }
            }
        }
    }
}