import QtQuick 2.0
import QtQuick.Window 2.0

Window {
    id: rootRect
    width: 300
    height: 300
    visible: true

    Rectangle {
        id: ball
        width: 20
        height: 20
        color: "Lime"

        anchors.verticalCenter: rootRect.verticalCenter

        property bool flag: false

        SequentialAnimation {
            running: true
            loops: Animation.Infinite
            NumberAnimation {
                target: ball
                property: "x"
                from: 0
                to: rootRect.width
                duration: 3000
            }
            ScriptAction { script: ball.flag = false }
        }

        onXChanged: {
            if (x >= 150 && !flag) {
                console.log("Center")
                flag = true
            }
        }
    }
}