FullScreen window can't be hidden

import QtQuick 2.12
import QtQuick.Window 2.12

Window 
{
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")
    Component.onCompleted: flags |= Qt.WindowFullscreenButtonHint    
    onClosing:
    {
        if (visibility == Window.FullScreen)
        {
            visibility = Window.Hidden;
            close.accepted = false;
        }
    }
}