[flexcoders] Re: Detecting List width from its itemRenderer

[Alexander]

Hello Alex and others,

--- In flexcoders@yahoogroups.com, Alex Harui <aha...@...> wrote:
> The renderer should be given an explicitWidth by the time its measure() 
> method gets called.  That would be a good time to choose a different size 
> avatar and report a different measuredHeight.

my problem is: when I increase the item size in my renderer,
I don't know how to change the rowHeight of the parent List
and thus the items are cut off.

I've prepared a reduced test case demonstrating my problem -

TestCase.mxml:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml";>
    <mx:HDividedBox width="100%" height="100%">
        <mx:List id="myList" width="40%" height="100%" 
          alternatingItemColors="[0xCCCCCC, 0xFFFFFF]"
          dataProvider="{['a;b;c', '1;2;3', '4;5', 'd', '6;7;8']}" 
          itemRenderer="RowRenderer"/>
        <mx:Label text="&lt;-- Resize the list" width="60%"/>
    </mx:HDividedBox>
</mx:Application>

RowRenderer.mxml:

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"; 
    width="100%" height="100%" 
    verticalScrollPolicy="off" horizontalScrollPolicy="off">

    <mx:Script>
    <![CDATA[
    [Bindable]
    private var _scale:Number = 0.8;

    override public function set data(obj:Object):void {
        var i:uint;

        super.data = obj;

        for (i = 0; i < _btn.length; i++)
            _btn[i].visible = false;

        if (obj != null) {
            var str:String = String(obj);
            var labels:Array = str.split(/;/);
            for (i = 0; i < _btn.length && i < labels.length; i++) {
                _btn[i].label = labels[i];
                _btn[i].visible = true;
            }
        }
    }

    override protected function measure():void {
        super.measure();

        measuredWidth=3 * 100 * _scale;
        measuredHeight=100 * _scale;

        measuredMinWidth = 3 * 50;
        measuredMinHeight = 50;
    }

    override protected function updateDisplayList(unscaledWidth:Number, 
unscaledHeight:Number):void {
        super.updateDisplayList(unscaledWidth, unscaledHeight);
        trace(unscaledWidth + ' x ' + unscaledHeight);
        _scale = (unscaledWidth > 3 * 100 ? 1.2 : 0.8);

        // XXX how to set the list rowHeigt=100*_scale here?
    }
    ]]>
    </mx:Script>

    <mx:HBox width="100%" horizontalAlign="center">
        <mx:Repeater id="_rpt" dataProvider="{[0, 1, 2]}">
            <mx:Button id="_btn" width="100" height="100" fontSize="24"
              textAlign="center" scaleX="{_scale}" scaleY="{_scale}"/>
        </mx:Repeater>
    </mx:HBox>

</mx:Canvas>