Flex sizing a component as wrapping the elements in custom layout

Question

I have a custom layout called as NewsLayout:

    override public function updateDisplayList(width:Number, height:Number)
        : void
    {
        super.updateDisplayList( width, height );

        var layoutTarget:GroupBase = target;

        var element:ILayoutElement;

        for( var i:int = 0; i < layoutTarget.numElements; i++ )
        {
            element = layoutTarget.getElementAt( i );


            if(i==0){
                element.setLayoutBoundsSize( NaN, NaN );
                element.setLayoutBoundsPosition( 0, 0 );
            }
            else if(i==1)
            {
                var refEl = layoutTarget.getElementAt( 0 );
                element.setLayoutBoundsSize( NaN, NaN );
                element.setLayoutBoundsPosition( 0, refEl.height+5);
            }
            else if(i==2)
            {
                var refEl = layoutTarget.getElementAt( 0 );
                var refEl2 = layoutTarget.getElementAt( 1 );
                element.setLayoutBoundsSize( NaN, NaN );                    
                element.setLayoutBoundsPosition( Math.max(refEl2.width,refEl.width)+5, 0);


            }
        }
    }

And my custom component uses this layout and three more. Its layout may change on fly . Whichever layout it uses, my component should wrap all the elements inside it.

For this I tried to override the measure method to resize the component according to components inside it. I am trying to calculate the bottom point of all items inside it like this. Unexpectedly y position of all elements is 0, but as you can see, I am setting the coordinates of them in layout class.

    override protected function measure():void {

            super.measure(); var max= 0;
            for(var i=0 ; i < this.numElements;i++)
            {
                if((this.getElementAt(i).height +this.getElementAt(i).y) > max)
                    max = this.getElementAt(i).height + this.getElementAt(i).y;// here y position is 0
            }
            //this.height =this.measuredHeight;
            this.measuredHeight = max;
            this.height = max;
            trace("maxheight:"+max);

What is the correct way to let the component wrap all the elements inside it, regardless the layout it uses?

Answer 1

In flex component lifecycle measure() call once and before updateDisplayList(); So your components has y position as 0; Try to use setActualSize(width, height) for all elements in updateDisplayList().