nooLight/LightGroup.qml

import QtQuick 2.0
import QtQuick.Controls 2.2

Item {
    id: root

    property string title: ""
    property QtObject lights: undefined

    Column {
        width: root.width

        spacing: 5

        GradientButton {
            width: root.width
            height: 40

            visible: Boolean(root.title)
            radius: 5

            Label {
                text: root.title
                anchors.centerIn: parent
            }
        }

        Row {
            id: buttonsRow

            width: root.width
            height: childrenRect.height

            spacing: 5

            Repeater {
                model: root.lights

                width: root.width

                GradientButton {
                    width: (root.width - buttonsRow.spacing * (root.lights.count - 1)) / root.lights.count
                    height: width / 2
                    radius: 5
                }
            }
        }
    }
}