import QtQuick 2.11
import QtQuick.Controls 2.4

ApplicationWindow {
    id: root
    height: 480
    width: 640
    visible: true

    MouseArea {
        anchors.fill: parent
        onDoubleClicked: {
            var w = otherWindowComponent.createObject(root)
            w.show()
            w.requestActivate() // same effect when removed
        }
    }

    Component {
        id: otherWindowComponent
        ApplicationWindow {
            id: child
            width: 400
            height: 300

            Rectangle {
                color: "blue"
                width: 100
                height: 100
                focus: true
            }
        }
    }
}