TextInput.openSoftwareInputPanel() cannot be opened from Component.onCompleted

import QtQuick 1.1
Rectangle {
    width: 360
    height: 360
    TextInput {
        id: input
        text: qsTr("Hello World")
        anchors.centerIn: parent
        Component.onCompleted: {
            input.forceActiveFocus();
            input.openSoftwareInputPanel();
        }
    }
}