Detect mouse click outside the modal window

jimcad

I have modal dialog where is popup window. Popup is closed when mouse is clicked outside of popup in modal window. But I'd like to close popup also when is clicked anywhere outside the popup. How this can be done?

import QtQuick 2.3
import QtQuick.Controls 1.2
import QtQuick.Window 2.1

ApplicationWindow {
    visible: true
    width: 640
    height: 480

    Button {
        text: "Open modal window"
        anchors.centerIn: parent
        onClicked: { modalWindow.show() }
    }

    Window {
        id: modalWindow
        width: 300
        height: 400
        modality: Qt.ApplicationModal
        Rectangle {
            anchors.fill: parent
            border.width: 1
            MouseArea {
                anchors.fill: parent
                onClicked: {
                    popupWindow.show()
                }
            }
            Button {
                anchors.top: parent.top
                anchors.right: parent.right
                text: "Close"
                onClicked: modalWindow.close()
            }
        }     

        Window {
            id: popupWindow
            flags: Qt.Popup
            width: 100
            height: 100
            x: Screen.width / 2
            y: Screen.height / 2
            Rectangle {
                anchors.fill: parent
                color: "green"
            }
        }       
    }
}

jimcad

A small clarification. Popup window should work the same way as menu or combobox, so it should be closed when you click anywhere outside popup.