リングクラス

/**
 * Copyright tkinjo ( http://wonderfl.net/user/tkinjo )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/lv7h
 */

package  
{
    import flash.display.Sprite;
    
    [SWF(width="465", height="465", backgroundColor="0xffffff", frameRate="60")] 
    /**
     * リングクラス
     * 
     * @author tkinjo
     */
    public class Main extends Sprite
    {
        
        public function Main() 
        {
            addChild( new Ring( 100, 10 ) );
        }
        
    }
    
}

import flash.display.*;

internal class Ring extends Sprite {
    
    public function get radius():Number { return _radius; }
    public function set radius(value:Number):void 
    {
        _radius = value;
        draw();
    }
    private var _radius:Number;
    
    
    
    public function get innerRadius():Number { return _innerRadius; }
    public function set innerRadius(value:Number):void 
    {
        _innerRadius = value;
        draw();
    }
    private var _innerRadius:Number;
    
    
    
    public function get color():Number { return _color; }
    public function set color(value:Number):void 
    {
        _color = value;
        draw();
    }
    private var _color:Number;
    
    
    
    public function Ring( radius:Number, innerRadius:Number = 0, color:Number = 0 ) {
        
        _radius = radius;
        _innerRadius = innerRadius;
        _color = color;
        
        draw();
    }
    
    
    
    private function draw():void {
        
        graphics.clear();
        graphics.beginFill( color );
        graphics.drawCircle( radius, radius, radius);
        if ( innerRadius != 0 )
            graphics.drawCircle( radius, radius, innerRadius );
        graphics.endFill();
    }
}