Custom itemRenderer - Bug?

Question

Hi, I have an example of some code that I can't figure out.
What I'm doing may not be the best way to do what I want, but I
believe is should work, and can't figure out why it doesn't. I have
a datagrid with two columns, and the second column uses a custom
itemRenderer to draw multiple circles depending on nested XML data
for that row. In the
set data function of my itemRenderer, I'm trying to get the
width of the column, and use that to calculate where to put my
circle, as a value of 1 to 10.
- The first time, the
set data is called four times where there are three rows
- The first time it's called, this.width is zero
- When resizing column widths, set data is called again - the
first time only for the 2nd and 3rd rows, but with the correct
width
- Subsequent times it's called for all three rows, but the
first row uses the LAST width, not the new width
Any ideas? Here's my code:
Project name is FlexSample, first file is FlexSample.mxml,
then other two files are MyComponents/MyItemRenderer.as and
MyComponents/PointComponent.as
FlexSample.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns="*"
width="100%" height="100%"
initialize="init()" horizontalGap="0" verticalGap="0" >
<mx:Script>
<![CDATA[
import mx.events.ResizeEvent;
import mx.controls.Alert;
import mx.rpc.events.ResultEvent;
import mx.rpc.events.FaultEvent;
import mx.rpc.http.HTTPService;
import mx.events.*;
[Bindable]
public var myXML:XML=
<ROWSET>
<ROW>
<POINTS>
<POINT>
<POINT_ID>90686</POINT_ID>
<X_VALUE>2</X_VALUE>
</POINT>
<POINT>
<POINT_ID>90806</POINT_ID>
<X_VALUE>8</X_VALUE>
</POINT>
</POINTS>
<NOTE_TX>Points are 2 and 8</NOTE_TX>
</ROW>
<ROW>
<POINTS>
<POINT>
<POINT_ID>90111</POINT_ID>
<X_VALUE>4</X_VALUE>
</POINT>
<POINT>
<POINT_ID>90222</POINT_ID>
<X_VALUE>6</X_VALUE>
</POINT>
</POINTS>
<NOTE_TX>Points are 4 and 6</NOTE_TX>
</ROW>
<ROW>
<POINTS>
<POINT>
<POINT_ID>90333</POINT_ID>
<X_VALUE>1</X_VALUE>
</POINT>
<POINT>
<POINT_ID>90444</POINT_ID>
<X_VALUE>10</X_VALUE>
</POINT>
</POINTS>
<NOTE_TX>Points are 1 and 10</NOTE_TX>
</ROW>
</ROWSET>;
]]>
</mx:Script>
<mx:DataGrid width="100%" height="100%" id="dgMain"
dataProvider="{myXML.ROW}"
fontFamily="Verdana" fontSize="10" color="#000066">
<mx:columns>
<mx:DataGridColumn headerText="Note"
dataField="NOTE_TX"/>
<mx:DataGridColumn headerText="Points" dataField="POINT"
id="dgcPoints"
itemRenderer="MyComponents.MyItemRenderer"/>
</mx:columns>
</mx:DataGrid>
</mx:Application>
MyItemRenderer.as
// ActionScript file
package MyComponents {
import mx.controls.*;
import mx.core.*;
import mx.controls.dataGridClasses.DataGridListData;
import mx.controls.listClasses.*;
import flash.display.*;
import mx.core.*;
import mx.controls.*;
import flash.events.*;
import mx.managers.PopUpManager;
import mx.events.*;
public class MyItemRenderer extends mx.core.Container
implements IListItemRenderer{
public function MyItemRenderer() {
super();
override public function set data(oValue:Object):void {
this.removeAllChildren();
//oValue contains whole ROW in XML format...
var n:int = 0;
if(this.width==0){
trace("set data:width 0!");
if (oValue != null && this.width>0) {
var m:int = this.getChildren().length;
var nWidth:int = this.width;
var xXML:XML = new XML(oValue);
for(var s:String in xXML.POINTS.children()){
var nXValue:int = xXML.POINTS.children()[s].X_VALUE;
//Total width is from 0-9, padding of 5 on left and right to
account for circle width
var n:int = (((nXValue -1)/10) * (this.width-10)) + 5;
trace("set data: Width:" + this.width + " XValue:" + nXValue
+ " X:" + n);
var u:PointComponent = new PointComponent(0x0000EE, n);
this.addChild(u);
PointComponent.as
package MyComponents
import mx.core.UIComponent;
import mx.controls.Alert;
public class PointComponent extends UIComponent
public function PointComponent(pnColor:uint, pnX:int){
super();
graphics.clear();
graphics.beginFill(pnColor);
graphics.drawCircle(pnX, 10, 7);
}

Answer 1

A complete runnable example, that's great, I will give it a
try.
In the meantime, for "...set data is called four times where
there are three rows...", I have noticed this as well but have no
explanation. The first time, the "value" object is "null", so I
always wrap the code in if (value != null) {}
I'll post when I get a chance to look at your sample.
Tracy