storeitemcollectionview.as

This is a Flex UIComponent that can be used 谋n a FLEX 3 mxml application as component written in act

package mx.item.view
{
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	
	import mx.item.collection.StoreItemCollection;
	import mx.ui.ScrollButton;
	
	public class StoreItemCollectionView extends Sprite
	{
		private var _data:StoreItemCollection;
		private var _frame:Sprite;
		private var _contents:Sprite;
		private var _mask:Sprite;
		private var _arrowUp:ScrollButton;
		private var _arrowDown:ScrollButton;
		private var _mouseDownEventHandler:Function;
		
		public function StoreItemCollectionView(data:StoreItemCollection, mouseDownEventHandler:Function):void
		{
			_data = data;
			_mouseDownEventHandler = mouseDownEventHandler;
			_data.addEventListener(Event.CHANGE,onUpdate);
			_frame = new Sprite();
			_frame.graphics.lineStyle(0, 0x000000, 1);
			_frame.graphics.beginFill(0x00FF00,0);
			_frame.graphics.drawRect(0,0,320,480);
			_frame.graphics.endFill();
			this.addChild(_frame);
			
		    _mask = new Sprite();
			_mask.graphics.lineStyle();
			_mask.graphics.beginFill(0xFF00FF, 1);
			_mask.graphics.drawRect(0,0,320,480);
			_mask.graphics.endFill();
			this.addChild(_mask);
			
			_arrowUp = new ScrollButton(1);
			_arrowUp.x = 320;
			this.addChild(_arrowUp);
			_arrowDown = new ScrollButton(0);
			_arrowDown.x =320;
			 this.addChild(_arrowDown);
			_arrowDown.y = 480 - _arrowDown.height;
			
			_arrowUp.addEventListener(MouseEvent.CLICK, onScrollUp);
			_arrowDown.addEventListener(MouseEvent.CLICK, onScrollDown);
			onUpdate(null);
				
		}
		
		private function onUpdate(event:Event):void {
			if(_contents != null) {
				removeChild(_contents);
			}
			_contents = new Sprite();
			this.addChild(_contents);
			_contents.mask = _mask;
			var itemView:StoreItemView;
			var itemY:Number = 0;
			var i:uint;
			for(i = 0; i < _data.count; i++) {
				itemView = new StoreItemView(_data.getItem(i));
				itemView.addEventListener(MouseEvent.MOUSE_DOWN,_mouseDownEventHandler);
				itemView.y = itemY;
				_contents.addChild(itemView);
				itemY += 120;
			}
			var scroll:Boolean = _contents.height > _frame.height;
			_arrowUp.visible = scroll;
			_arrowDown.visible = scroll;
			
		}
		
		private function onScrollUp(event:MouseEvent):void {
			if (_contents.y < _frame.y ) {
				_contents.y += 120;
			}
		}
 
        private function onScrollDown(event:MouseEvent):void { 
        	if(_contents.y > - _contents.height + _frame.height) {
        		_contents.y -= 120;
        	}
	}}
}