import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.0

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    Flickable {
        id: flick
        anchors.fill: parent
        contentWidth: 5000
        contentHeight: 5000
        onContentXChanged: Qt.callLater(rect.update)
        onContentYChanged: Qt.callLater(rect.update)
        Rectangle {
            color: 'red'
            x: 2000
            y: 2000
            width: 1000
            height: 1000
        }
        Rectangle {
            id: rect
            color: 'green'
            width: flick.width - 200
            height: flick.height - 200
            function update() {
                x = flick.contentX + 100
                y = flick.contentY + 100
            }
        }
    }
}