自定义动画效果(Iris动画修改)

NewIrisEffert.as

 

package tree...{
    //导入代码中使用的对象
    import mx.effects.MaskEffect;
    import mx.effects.EffectInstance;
    import mx.controls.SWFLoader;
    import flash.display.Shape;
    import flash.geom.Rectangle;
    import mx.core.FlexShape;
    import flash.display.Graphics;

    public class NewIrisEffect extends MaskEffect...{
        //表明动画采用的起始点类型
        public var position:String;     //这个参数非常有用！
        //构造函数
        public function NewIrisEffect(target:Object=null)...{
            super(target);
            //定义实例类型为NewIrisInstance,代替原来的IrisInstance.NewIrisInstance是我们新建的对像。
            instanceClass=NewIrisInstance;
            //定义新的createMaskFunction,此函数用来绘制遮罩层
            this.createMaskFunction=createLargeMask;
        }
        //此函数用来绘制遮罩层
        public function createLargeMask(targ:Object,bounds:Rectangle):Shape...{
            //绘制前，首先得到目标的实际尺寸，来确定遮罩层的尺寸。targetVisualBounds包含了目标可视区域的长和宽
            var targetWidth:Number = bounds.width / Math.abs(targ.scaleX);
            var targetHeight:Number = bounds.height / Math.abs(targ.scaleY);
            if (targ is SWFLoader)...{
                //
                targ.validateDisplayList();
                if(targ.content)...{
                    targetWidth = targ.contentWidth;
                    targetHeight = targ.contentHeight;        
                }
            }
            //创建遮罩层的表现对象
            var newMask:Shape=new FlexShape();
            var g:Graphics=newMask.graphics;
            //设定填充色
            g.beginFill(0xFFFF00);
            //绘制椭圆，drawEllipse是Griphics对象的绘制方法之一,默认情况下绘制矩形
            g.drawEllipse(0,0,targetWidth,targetHeight);
            
            g.endFill();
            //判断是否跳转
            if(target.rotation==0)...{
                //如果没有跳转
                newMask.width=targetWidth;
                newMask.height=targetHeight;
            }else...{
                //如果跳转，重新计算遮罩层的大小
                //得到角度的弧度数
                var angle:Number=targ.rotation * Math.PI/180;
                var sin:Number=Math.sin(angle);
                var cos:Number=Math.cos(angle);
                //计算出新尺寸
                newMask.width=Math.abs(targetWidth * cos-targetHeight * sin);
                newMask.height=Math.abs(targetWidth * sin + targetHeight * cos);
            }
            
            return newMask;
        }
        //覆盖父类的initInstance方法
        //将生成类的属性传到实例对象中，这个方法在对象内部被调用
        override protected function initInstance(instance:EffectInstance):void...{
            //调用父类的同名方法
            super.initInstance(instance);
            //创建新的实例
            var maskEffectInstance:NewIrisInstance=NewIrisInstance(instance);
            //传递参数给实例
            maskEffectInstance.showTarget=showTarget;
            maskEffectInstance.xFrom=xFrom;
            maskEffectInstance.yFrom=yFrom;
            maskEffectInstance.xTo=xTo;
            maskEffectInstance.yTo=yTo;
            maskEffectInstance.scaleXFrom=scaleXFrom;
            maskEffectInstance.scaleXTo=scaleXTo;
            maskEffectInstance.scaleYFrom=scaleYFrom;
            maskEffectInstance.scaleYTo=scaleYTo;
            //确定动画执行的初使位置
            maskEffectInstance.position=position;
        }
        
    }
}

 NewIrisInstance.as

 

package tree...{
    import mx.effects.effectClasses.MaskEffectInstance;
    import mx.controls.SWFLoader;
    
    public class NewIrisInstance extends MaskEffectInstance...{
        //新添加的参数，用来确定动画播放时的初使位置
        public var position:String;          //这个参数非常有用！
        //构造函数
        public function NewIrisInstance(target:Object)...{    
            super(target);
        }
        //覆盖父类的方法,initMaskEffect主要初使化遮罩动画的信息
        override protected function initMaskEffect():void...{
            //调用父类的同名方法
            super.initMaskEffect();
            //得到目标的实际尺寸，targetVisualBounds包含了目标可视区域的长和宽
            var targetWidth:Number = targetVisualBounds.width / Math.abs(target.scaleX);
            var targetHeight:Number = targetVisualBounds.height / Math.abs(target.scaleY);
            //如果目标是SWFLoader对象，则计算加载内容的尺寸，而不是目标本身的尺寸
            if (target is SWFLoader)...{
                targetWidth = target.contentWidth;
                targetHeight = target.contentHeight;        
            }
            //如果showTarget为true，表示显示目标对象
            if (showTarget)...{
                //定义x,y方向的起始放缩值
                scaleXFrom = 0;
                scaleYFrom = 0;
                scaleXTo = 1;
                scaleYTo = 1;
                //依据position属性决定起点的位置
                //如果中心是左上角
                if(position=="leftTop")...{
                    //从左上角开始
                    //targetVisualBounds还包含了目标可视区域的可视域的坐标位置
                    xFrom = targetVisualBounds.x;
                    yFrom = targetVisualBounds.y;
                }else if(position=="rightBottom")...{
                    //如果中心是右下角,从右下角开始
                    xFrom = targetWidth + targetVisualBounds.x;
                    yFrom = targetHeight + targetVisualBounds.y;    
                }else...{
                    //从默认中心开始，保持原来的计算方式不变
                    xFrom = targetWidth / 2 + targetVisualBounds.x;
                    yFrom = targetHeight / 2 + targetVisualBounds.y;
                }
                //确定最后的坐标
                xTo = targetVisualBounds.x;
                yTo = targetVisualBounds.y;
            }else...{
                //如果是隐藏目标
                scaleXFrom = 1;
                scaleYFrom = 1;
                scaleXTo = 0;
                scaleYTo = 0;
                //目标的起始位置
                xFrom = targetVisualBounds.x;
                yFrom = targetVisualBounds.y;
                //确定最后的坐标
                if(position=="leftTop")...{
                    xFrom = targetVisualBounds.x;
                    yFrom = targetVisualBounds.y;
                }else if(position=="rightBottom")...{
                    xFrom = targetWidth + targetVisualBounds.x;
                    yFrom = targetHeight + targetVisualBounds.y;    
                }else...{
                    xTo = targetWidth / 2 + targetVisualBounds.x;
                    yTo = targetHeight / 2 + targetVisualBounds.y;
                }
                
            }
        }
    }


}

 

NewIris.mxml

 

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:tree="tree.*">
    <!-- 定义动画效果   -->
    <tree:NewIrisEffect position="leftTop" id="myIris" duration="1000"></tree:NewIrisEffect>
    <!-- 动画效果绑定在图片上  -->
    <mx:Image x="10" y="10" source="img/5.jpg" width="125" height="190" id="image" showEffect="{myIris}" hideEffect="{myIris}"/>
    <mx:Button x="36" y="227" label="播放" click="image.visible=!image.visible"/>
    
</mx:Application>