FactComboBox.qml

import QtQuick 2.3
import QtQuick.Controls 1.2
import QtQuick.Controls.Styles 1.4

import QGroundControl.FactSystem 1.0
import QGroundControl.Palette 1.0
import QGroundControl.Controls 1.0

QGCComboBox {
    property Fact fact: Fact { }
    property bool indexModel: true  ///< true: model must be specifed, selected index is fact value, false: use enum meta data

    model: fact ? fact.enumStrings : null

    currentIndex: indexModel ? fact.value : fact.enumIndex

    onActivated: {
        if (indexModel) {
            fact.value = index
        } else {
            fact.value = fact.enumValues[index]
        }
    }
}