Flex custom item renderer for the displayed item in the combobox

Question

I am using a custom item renderer in a combobox to display a custom drawing instead of the default text label.

This works fine for the dropdown list but the displayed item ( when the list is closed) is still the textual representation of my object.

Is there a way to have the displayed item rendered the same way as the one in the dropdown?

Answer 1

By default you cannot do this. However, if you extend ComboBox you can add this functionality easily. Here is a quick example, it is a rough version and probably needs testing / tweaking but it shows how you could accomplish this.

package
{
    import mx.controls.ComboBox;
    import mx.core.UIComponent;

    public class ComboBox2 extends ComboBox
    {
        public function ComboBox2()
        {
            super();
        }

        protected var textInputReplacement:UIComponent;

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

            if ( !textInputReplacement ) {
                if ( itemRenderer != null ) {
                    //remove the default textInput
                    removeChild(textInput);

                    //create a new itemRenderer to use in place of the text input
                    textInputReplacement = itemRenderer.newInstance();
                    addChild(textInputReplacement);
                }
            }
        }

        override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void {
            super.updateDisplayList(unscaledWidth, unscaledHeight);

            if ( textInputReplacement ) {
                textInputReplacement.width = unscaledWidth;
                textInputReplacement.height = unscaledHeight;
            }
        }
    }
}