FocusEvent  - AS3

package {
    import flash.display.Sprite;
    import flash.display.DisplayObject;
    import flash.events.FocusEvent;
    import flash.events.IEventDispatcher;

    public class FocusEventExample extends Sprite {
        private var gutter:uint = 5;
        private var childCount:uint = 5;

        public function FocusEventExample() {
            var child:Sprite;
            for(var i:uint; i < childCount; i++) {
                child = new CustomSprite();
                configureListeners(child);
                addChild(child);
            }
            refreshLayout();
        }

        private function configureListeners(dispatcher:IEventDispatcher):void {
            dispatcher.addEventListener(FocusEvent.FOCUS_IN, focusInHandler);
            dispatcher.addEventListener(FocusEvent.FOCUS_OUT, focusOutHandler);
            dispatcher.addEventListener(FocusEvent.KEY_FOCUS_CHANGE, keyFocusChangeHandler);
            dispatcher.addEventListener(FocusEvent.MOUSE_FOCUS_CHANGE, mouseFocusChangeHandler);
        }

        private function refreshLayout():void {
            var ln:uint = numChildren;
            var child:DisplayObject = getChildAt(0);
            var lastChild:DisplayObject = child;
            for(var i:uint = 1; i < ln; i++) {
                child = getChildAt(i);
                child.x = lastChild.x + lastChild.width + gutter;
                lastChild = child;
            }
        }

        private function focusInHandler(event:FocusEvent):void {
            var target:CustomSprite = CustomSprite(event.target);
            trace("focusInHandler: " + target.name);
        }

        private function focusOutHandler(event:FocusEvent):void {
            var target:CustomSprite = CustomSprite(event.target);
            trace("focusOutHandler: " + target.name);
        }

        private function keyFocusChangeHandler(event:FocusEvent):void {
            if(event.keyCode == 39 || event.keyCode == 37){
                event.preventDefault()
            }
            var target:CustomSprite = CustomSprite(event.target);
            trace("keyFocusChangeHandler: " + target.name);
        }
        private function mouseFocusChangeHandler(event:FocusEvent):void {
            var target:CustomSprite = CustomSprite(event.target);
            trace("mouseFocusChangeHandler: " + target.name);
        }
    }
}

import flash.display.Sprite;
import flash.events.MouseEvent;

class CustomSprite extends Sprite {
    private var size:uint = 50;
    private var bgColor:uint = 0x00CCFF;

    public function CustomSprite() {
        buttonMode = true;
        useHandCursor = true;
        addEventListener(MouseEvent.CLICK, clickHandler);
        draw(size, size);
    }

    private function draw(w:uint, h:uint):void {
        graphics.beginFill(bgColor);
        graphics.drawRect(0, 0, w, h);
        graphics.endFill();
    }

    private function clickHandler(event:MouseEvent):void {
        var target:Sprite = Sprite(event.target);
        trace("clickHandler: " + target.name);
        stage.focus = target;
    }
}