[Bindable]
public var currentFacture:ArrayCollection = new ArrayCollection([
  {
    label: "Label 1",
    focused: false
  },
  {
    label: "Label 2",
    focused: false
  },
  {
    label: "Label 3",
    focused: false
  }
];

<s:List id="articleDetailsList"
            width="100%"
            height="100%"
            dataProvider="{currentFacture}"
            selectionColor="#FFFFFF"
            rollOverColor="gray"
            horizontalScrollPolicy="off"
            contentBackgroundAlpha="0"
            borderAlpha="0"
            allowMultipleSelection="false">
    <s:itemRenderer>
        <fx:Component>
            <s:ItemRenderer width="100%" click="outerDocument.itemClicked(event)">
                <fx:Script>
                    override public function set data(value:Object):void
                    {
                        super.data = value;
                        if (value.focused) {
                          //set focus
                        }
                    }
                </fx:Script>

                <s:HGroup
                        width="100%"
                        gap="0"
                        paddingTop="10"
                        paddingBottom="5"
                        verticalAlign="bottom">
                    <s:TextInput id="articleQte" text="{data.label}" />
                </s:HGroup>
            </s:ItemRenderer>
        </fx:Component>
    </s:itemRenderer>
</s:List>

//somehwere else in your code to trigger focus on one of the text inputs'
var element = currentFacture.getElementAt(<some index>);

//this is needed if there is no way for the collection view to know about the update to the item, such as the data you're changing not being bindable possibly. This informes the ICollectionView that it's been updated and then the List would update to send in the new data object to its set data method.
currentFacture.itemUpdated(element);