Add extended Scroller to extended spark List in Flex

Question

I'm trying to add a custom Scroller.as (extended from spark.components.Scroller) to a InfiniteScrollList.as (extended from spark.components.list)

I wrote the following MXML code:

<list:InfiniteScrollList width="100%" height="100%" id="EventsList" useVirtualLayout="true">
    <list:scroller>
         <list:Scroller/> <!-- The Scroller.as Class -->
    </list:scroller>
</list:InfiniteScrollList>

The List behavior works well but the extended Scroller component does not function at all.
What is the correct way to add this scroller functionality (in MXML or ActionScript) to the list?

Answer 1

The s:Scroller is used by wrapping it around the content or DataGroup. But the List class wraps all that functionality inside of it's skin, so I believe that in order to create a custom Scroller for a List, you actually need to do within the SkinClass.

<list:InfiniteScrollList  width="100%" height="100%"  id="EventsList"
      useVirtualLayout="true" skinClass="MyListSkin" />

MyListSkin.mxml:

<s:SparkSkin xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark"
  xmlns:fb="http://ns.adobe.com/flashbuilder/2009" minWidth="112"> 

<fx:Metadata>
    [HostComponent("spark.components.Scroller")]
</fx:Metadata> 

<s:states>
    <s:State name="normal" />
    <s:State name="disabled" />
</s:states>


    <!-- The Scroller.as Class -->
    <list:Scroller left="0" top="0" right="0" bottom="0" id="scroller" hasFocusableChildren="false">
        <!--- @copy spark.components.SkinnableDataContainer#dataGroup -->
        <s:DataGroup id="dataGroup" itemRenderer="spark.skins.spark.DefaultItemRenderer">
            <s:layout>
                <!--- The default layout is vertical and measures at least for 5 rows.  
                When switching to a different layout, HorizontalLayout for example,
                make sure to adjust the minWidth, minHeight sizes of the skin -->
                <s:VerticalLayout gap="0" horizontalAlign="contentJustify" requestedMinRowCount="5" />
            </s:layout>
        </s:DataGroup>
    </list:Scroller/>
</s:SparkSkin>