import QtQuick 2.12
import QtQuick.Window 2.12

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

    Component.onCompleted: {
        console.log("win")
    }

    Rectangle{
        width: 30
        height: 30
        color: "green"
        Component.onCompleted: {
            console.log("rec 1")
        }
    }

    Rectangle{
        width: 20
        height: 20
        color: "red"
        Component.onCompleted: {
            console.log("rec 2")
        }
    }
}

qml: win
qml: rec 2
qml: rec 1