package
{
    import flash.display.Sprite;
    import flash.events.MouseEvent;
 
    public class GridView extends Sprite
    {
        private var _cellSize:int=40;
        private var _grid:Grid;
 
        //构造函数
        public function GridView(grid:Grid)
        {
            _grid=grid;
            drawGrid();
            findPath();
            addEventListener(MouseEvent.CLICK, onGridClick);
        }
 
        //画格子
        public function drawGrid():void
        {
            graphics.clear();
            for (var i:int=0; i < _grid.numCols; i++)
            {
                for (var j:int=0; j < _grid.numRows; j++)
                {
                    var node:Node=_grid.getNode(i, j);
                    graphics.lineStyle(0);
                    graphics.beginFill(getColor(node));
                    graphics.drawRect(i * _cellSize, j * _cellSize, _cellSize, _cellSize);
                }
            }
        }
 
        //取得节点颜色
        private function getColor(node:Node):uint
        {
            if (!node.walkable)
            {
                return 0;
            }
            if (node == _grid.startNode)
            {
                return 0xffff00;
            }
            if (node == _grid.endNode)
            {
                return 0xff0000;
            }
            return 0xffffff;
        }
 
        //网格点击事件
        private function onGridClick(event:MouseEvent):void
        {
            var xpos:int=Math.floor(event.localX / _cellSize);
            var ypos:int=Math.floor(event.localY / _cellSize);
            _grid.setWalkable(xpos, ypos, !_grid.getNode(xpos, ypos).walkable);
            drawGrid();
            findPath();
        }
 
        //寻找路径
        private function findPath():void
        {
            var astar:AStar=new AStar;
            if (astar.findPath(_grid))
            {
                showVisited(astar);
                showPath(astar);
            }
        }
 
        //显示open列表与close列表
        private function showVisited(astar:AStar):void
        {
             
             
            var opened:Array=astar.openArray;
            for (var i:int=0; i < opened.length; i++)
            {
                var node:Node = opened[i] as Node;
                 
                graphics.beginFill(0xcccccc);
                if (node==_grid.startNode){
                    graphics.beginFill(0xffff00);
                }
                 
                graphics.drawRect(opened[i].x * _cellSize, opened[i].y * _cellSize, _cellSize, _cellSize);
                graphics.endFill();
            }
             
            var closed:Array=astar.closedArray;
            for (i=0; i < closed.length; i++)
            {
                node = opened[i] as Node;
                 
                graphics.beginFill(0xffff00);               
                 
                graphics.drawRect(closed[i].x * _cellSize, closed[i].y * _cellSize, _cellSize, _cellSize);
                graphics.endFill();
            }
        }
 
        //显示路径
        private function showPath(astar:AStar):void
        {
            var path:Array=astar.path;
            for (var i:int=0; i < path.length; i++)
            {
                graphics.lineStyle(0);
                graphics.beginFill(0);
                graphics.drawCircle(path[i].x * _cellSize + _cellSize / 2, path[i].y * _cellSize + _cellSize / 2, _cellSize / 3);
            }
        }
    }
}