Problem getting vertical scroll bar in tree

Question

Hi,
I am adding nodes to a tree control dynamically. But somehow,
a vertical scroll bar doesn't appear during the process. I guess,
somehow, the tree is not able to detect the change in the height,
hence, is not giving the vertical scroll bar. However, after a node
has been populated with the sub-nodes, when I close that node and
re-open it, then the scroll bar appears. I really need to fix it as
soon as possible. Plz help!
Thanks in advance,
Cheree

Answer 1

Seems like Flex 4 is working fine:
This is the updated code working on Flex 4.6 using XMLCollection:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" applicationComplete="application1_applicationCompleteHandler(event)">
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <fx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.collections.XMLListCollection;
            import mx.controls.Tree;
            import mx.events.FlexEvent;
            import mx.events.TreeEvent;
            [Bindable]
            public var treeData: XMLListCollection=new XMLListCollection();
            private var hasRun: Boolean = false;
            //finalSrcList is the ArrayCollection that has value objects returned from data base by a remote object.
            public function populateTree(event:TreeEvent): void{
                if (hasRun == false){
                    hasRun = true;
                    var parentNode:XML=event.item as XML;
                    var temp:XML;
                    var i: int;
                    var finalSrcList: ArrayCollection = new ArrayCollection();
                    // Prepare source list
                    for (i=0; i<10; i++){
                        var item = new Object();
                        item.attribute1 = "attribute " + i.toString();
                        item.attribute2 = i.toString();
                        finalSrcList.addItem(item);
                    for(i=0;i<finalSrcList.length;i++){
                        temp= <node label={finalSrcList[i].attribute1} id={finalSrcList[i].attribute2} isBranch="true"/>;
                        event.currentTarget.dataDescriptor.addChildAt(parentNode,temp,0);
            protected function application1_applicationCompleteHandler(event:FlexEvent):void
                var rootItem: XML;
                rootItem = <root label="root" id="1000">
                    <node label="level1" id="2000" isBranch="true"/>
                    </root>;                                   
                treeData.addItem(rootItem);
        ]]>
    </fx:Script>
    <mx:Panel width="600" height="250" paddingBottom="20" paddingLeft="20" paddingRight="20" paddingTop="20"
              verticalAlign="middle" horizontalAlign="center">
        <s:Label>
This is using XMLCollection
        </s:Label>
        <mx:Tree id="funcTree" height="100%" width="100%" dataProvider="{treeData}" labelField="@label" showRoot="false"
                 itemOpen="populateTree(event)" />       
    </mx:Panel>                  
</s:Application>