import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Controls 2.4

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

    Page {
        id: app
        anchors.fill: parent
        Button {
            id: onOffBt
            anchors.centerIn: parent

            height: parent.height * 0.5
            width: height

            text: "on/off"

            background: Rectangle {
                color: onOffBt.pressed ? "lightgrey":"grey"
                radius: height / 2
            }
        }
    }
}