ActionScript 3 中的圆形滑块

我希望在 ActionScript 中添加一个圆形滑块，非常类似于这一页 http://interface.eyecon.ro/demos/drag_vr.html shows:

它最终会改变对象的色调（返回 CMY 值），但如果它只是吐出程度，我完全可以使用它。如果您知道任何具有此功能的资源、教程、伪代码或片段，我将非常感激。谢谢！

下面是我对这个问题的解决方案。

值得注意的是，Flash 中的角度是在radians http://en.wikipedia.org/wiki/Radian而不是度数，这就是为什么您会注意到代码中的转换方法。就我个人而言，我发现以度为单位设置角度更容易可视化和理解，这就是为什么圆形滑块构造函数接受一个以度为单位的值以及为什么圆形滑块事件class 调度度数和弧度。

使用案例：

var circleSlider:CircleSlider = new CircleSlider(100, 270);
circleSlider.x = stage.stageWidth / 2;
circleSlider.y = stage.stageHeight / 2;
circleSlider.addEventListener(CircleSliderEvent.CHANGE, circleSliderEventHandler);

addChild(circleSlider);

function circleSliderEventHandler(event:CircleSliderEvent):void
{
    trace(event.degrees, event.radians);
}

圆滑块类：

package
{
    //Imports
    import flash.display.Sprite;
    import flash.display.Shape;
    import flash.events.Event;
    import flash.events.MouseEvent;

    //Class
    public class CircleSlider extends Sprite
    {
        //Properties
        private var mRadius:uint;
        private var mAngle:Number;
        private var mThumb:Sprite;

        //Constructor
        public function CircleSlider(radius:uint, degrees:Number)
        {
            mRadius = radius;
            mAngle = degrees;

            init();
        }

        //Init
        private function init():void
        {
            createCircle();
            createThumb();
            positionThumb(degreesToRadians(mAngle));
        }

        //Create Circle
        private function createCircle():void
        {
            var circle:Shape = new Shape();
            circle.graphics.lineStyle(4.0, 0xFFDDDD, 1.0);
            circle.graphics.drawCircle(0, 0, mRadius);

            addChild(circle);
        }

        //Create Thumb
        private function createThumb():void
        {
            mThumb = new Sprite();
            mThumb.graphics.beginFill(0xFF2222, 1.0);
            mThumb.graphics.drawCircle(0, 0, 10);
            mThumb.graphics.endFill();

            mThumb.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownEventHandler);

            addChild(mThumb);
        }

        //Mouse Down Event Handler
        private function mouseDownEventHandler(event:MouseEvent):void
        {
            mThumb.addEventListener(Event.ENTER_FRAME, enterFrameEventHandler);

            stage.addEventListener(MouseEvent.MOUSE_UP, mouseUpEventHandler);
            stage.addEventListener(Event.MOUSE_LEAVE, mouseUpEventHandler);
        }

        //Enter Frame Event Handler
        private function enterFrameEventHandler(event:Event):void
        {
            positionThumb(Math.atan2(mouseY, mouseX));
        }

        //Mouse Up Event Handler
        private function mouseUpEventHandler(event:MouseEvent):void
        {
            mThumb.removeEventListener(Event.ENTER_FRAME, enterFrameEventHandler);

            stage.removeEventListener(MouseEvent.MOUSE_UP, mouseUpEventHandler);
            stage.removeEventListener(Event.MOUSE_LEAVE, mouseUpEventHandler);
        }

        //Position Thumb
        private function positionThumb(radians:Number):void
        {
            mThumb.x = Math.cos(radians) * mRadius;
            mThumb.y = Math.sin(radians) * mRadius;

            mAngle = radiansToDegrees(radians);

            dispatchEvent(new CircleSliderEvent(CircleSliderEvent.CHANGE, mAngle, radians));
        }

        //Degrees To Radians
        private function degreesToRadians(degrees:Number):Number
        {
            return degrees * Math.PI / 180;
        }

        //Radians To Degrees
        private function radiansToDegrees(radians:Number):Number
        {
            return radians * 180 / Math.PI;
        }

        //Set Angle
        public function set angle(degrees:Number):void
        {
            positionThumb(degreesToRadians(degrees));
        }

        //Get Angle
        public function get angle():Number
        {
            return mAngle;
        }
    }
}

CircleSlider事件类：

package
{
    //Imports
    import flash.events.Event;

    //Class
    public class CircleSliderEvent extends Event
    {
        //Constants
        public static const CHANGE:String = "change";

        //Properties
        public var degrees:Number;
        public var radians:Number;

        //Constructor
        public function CircleSliderEvent (type:String, degrees:Number = NaN, radians:Number = NaN) 
        {
            super(type);

            this.degrees = degrees;
            this.radians = radians;
        }

        //Clone
        public override function clone():Event
        {
            return new CircleSliderEvent (type, degrees, radians);
        }

        //To String
        public override function toString():String
        {
            return formatToString("CircleSliderEvent", "type", "degrees", "radians");
        }
    }
}