Question

I am providing u the sample code that i have did so far. What i want to do is when i click on the Down button Tilelist slowly scroll and changes the data. though data changed by clicking on the down button but no effect is shown. i have searched a lot on the net but i can’t find any better way for that. If its possible then please give the best way for that.

Here is my sample code that i have did so far

<?xml version="1.0"?>

<mx:Sequence id="dataChangeEffectSequence">
    <mx:Move duration="1500" easingFunction="{Elastic.easeOut}" perElementOffset="20"/>
</mx:Sequence>

<mx:Script>
    <![CDATA[
        import mx.effects.easing.Elastic;
        import mx.controls.Alert;
        import mx.events.ScrollEvent;

        private var arrImage:Array = [
            {source:"Images/1.png",tooltip:"1"},
            {source:"Images/2.png",tooltip:"2"},
            {source:"Images/3.png",tooltip:"3"},
            {source:"Images/4.png",tooltip:"4"},
            {source:"Images/5.png",tooltip:"5"},
            {source:"Images/6.png",tooltip:"6"},
            {source:"Images/7.png",tooltip:"7"},
            {source:"Images/8.png",tooltip:"8"},
            {source:"Images/9.png",tooltip:"9"},
            {source:"Images/10.png",tooltip:"10"}];

        public function onInit():void
        {
            tileList.dataProvider = arrImage;
        }

        public function btnUP_click():void
        {
            var scrollPosition:int = tileList.verticalScrollPosition - 1;

            if(scrollPosition >= 0)
            {
                tileList.verticalScrollPosition = scrollPosition;
            }
            else
            {
                tileList.verticalScrollPosition = 0;
            }
        }

        public function btnDown_click():void
        {
            var scrollPosition:int = tileList.verticalScrollPosition + 1;

            if(scrollPosition <= tileList.maxVerticalScrollPosition)
            {
                tileList.verticalScrollPosition = scrollPosition;
            }               
        }

    ]]>
</mx:Script>

<mx:Button width="100" label="UP" id="btnUP" click="{btnUP_click();}" />

<mx:TileList id="tileList" dataProvider="{arrImage}" columnCount="1" columnWidth="100"
    useRollOver="false" selectable="false" backgroundAlpha="0" borderStyle="none" 
    rowHeight="65" verticalScrollPolicy="off" horizontalScrollPolicy="off"
    itemsChangeEffect="{dataChangeEffectSequence}" >
    <mx:itemRenderer>
        <mx:Component>
            <mx:VBox width="100%" height="100%" horizontalAlign="center" verticalGap="0"
                verticalAlign="middle" horizontalScrollPolicy="off" verticalScrollPolicy="off">
                <mx:Script>
                    <![CDATA[
                        import mx.controls.Alert;
                        override public function set data(value:Object):void
                        {
                            if(value !=null)
                            {
                                super.data = value;
                                if(img !=null)
                                {
                                    img.source = data.source;
                                    img.toolTip = data.tooltip;
                                }
                            }
                        }
                    ]]>
                </mx:Script>
                <mx:Image id="img" showEffect="{outerDocument.dataChangeEffectSequence}" />
            </mx:VBox>
        </mx:Component>
    </mx:itemRenderer>
</mx:TileList>

<mx:Button width="100" label="DOWN" id="btnDown" click="{btnDown_click();}" />

</mx:Application>

Thanks in advance..

Answer 1

Put the TileList inside a Container (such as Canvas or VBox) and force it to be the full height of all the items (if you have variableRowHeight, that might be a little complex). Then handle the scrolling on the VBox, not the TileList.

Also note that VBox has a lot of overhead as an itemRenderer. You might want to consider just putting Image in there. It has horizontalAlign and verticalAlign properties.