ToolTip类，趋于完美

东西虽小，内容丰富：自定义，缓动，淡入、淡出，自动调整位置。

package myas

{

        import flash.display.*;

        import flash.events.*;

        import flash.filters.*;

        import flash.geom.*;

        import flash.text.*;

        //import flash.utils.Timer;



        import fl.transitions.Tween;

        import fl.transitions.easing.*;

        import fl.transitions.TweenEvent;





        /**

         * Example:

                var tt:ToolTip = new ToolTip();

                tt.show( DisplayObject, "", "这里是信息" );

         或：

         var tf:TextFormat = new TextFormat();

        tf.bold = true;

        tf.size = 12;

        tf.color = 0xff0000;

        var contentFormat:TextFormat = new TextFormat();

        contentFormat.size = 14;

        contentFormat.color = 0xFFFFFF;

        contentFormat.bold = false;

        

        var tt:ToolTip = new ToolTip();

        tt.hook = true;

        tt.hookSize = 20;

        tt.cornerRadius = 20;

        tt.align = "center";

        tt.titleFormat = tf;

        tt.contentFormat = contentFormat;

        tt.show( DisplayObject, "Title Of This ToolTip", "Some Copy that would go below the ToolTip Title" );

         *

         ****** by zcheng  2011-3-22 [e-mail]

         基于* @author Duncan Reid, www.hy-brid.com  * @date October 17, 2008  * @version 1.1

         *

         */



        public class ToolTip extends Sprite

        {

                //objects

                private var _stage:Stage;

                private var _parentObject:DisplayObject;

                private var _tf:TextField;// title field

                private var _cf:TextField;//content field

                private var _tween:Tween;



                //formats

                private var _titleFormat:TextFormat;

                private var _contentFormat:TextFormat;



                /* check for format override */

                private var _titleOverride:Boolean = false;

                private var _contentOverride:Boolean = false;



                //defaults

                private var _defaultWidth:Number = 200;//宽

                private var _buffer:Number = 10;//四周留白数

                private var _align:String = "right";//箭头位置

                private var _cornerRadius:Number = 4;//圆角度数

                private var _bgColors:Array = [0xFFF4E1,0xFFF4E1];

                //private var _bgColors:Array = [0xB5FEB4,0x003300];//背景色

                private var _autoSize:Boolean = false;//自动调整大小

                private var _hookEnabled:Boolean = true;//有无箭头

                //private var _delay:Number = 0;  //延迟出现毫秒数，已精简

                private var _hookSize:Number = 10;//箭头大小



                //offsets

                private var _offSet:Number;

                private var _hookOffSet:Number;





                public function ToolTip():void

                {

                        //do not disturb parent display object mouse events

                        this.mouseEnabled = false;

                        this.buttonMode = false;

                        this.mouseChildren = false;

                        //setup delay timer

                        /*_timer = new Timer(this._delay, 1);

                                    _timer.addEventListener("timer", timerHandler);*/

                        this.animate(true);

                }



                public function show( p:DisplayObject, title:String, content:String=null ):void

                {

                        //get the stage from the parent

                        this._stage = p.stage;

                        this._parentObject = p;



                        this.addCopy( title, content );

                        this.setOffset();

                        this.drawBG();

                        this.bgGlow();



                        //initialize coordinates

                        var parentCoords:Point = new Point(_parentObject.mouseX,_parentObject.mouseY);

                        var globalPoint:Point = p.localToGlobal(parentCoords);

                        this.x = globalPoint.x + this._offSet;

                        this.y = globalPoint.y - this.height - 10;



                        this.alpha = 0;

                        this._stage.addChild( this );

                        this._parentObject.addEventListener( MouseEvent.MOUSE_OUT, this.onMouseOut );

                        //removed mouse move handler in lieu of enterframe for smoother movement;

                        //this._parentObject.addEventListener( MouseEvent.MOUSE_MOVE, this.onMouseMovement );



                        this.follow( true );

                        //_timer.start();

                }



                public function hide():void

                {

                        this.animate( false );

                }



                /*private function timerHandler( event:TimerEvent ):void {

                this.animate(true);

                }*/



                private function onMouseOut( event:MouseEvent ):void

                {

                        event.currentTarget.removeEventListener(event.type, arguments.callee);

                        this.hide();

                }



                private function follow( value:Boolean ):void

                {

                        if (value)

                        {

                                addEventListener( Event.ENTER_FRAME, this.eof );

                        }

                        else

                        {

                                removeEventListener( Event.ENTER_FRAME, this.eof );

                        }

                }



                private function eof( event:Event ):void

                {

                        this.position();

                }



                private function position():void

                {

                        var speed:Number = 3;

                        var parentCoords:Point = new Point(_parentObject.mouseX,_parentObject.mouseY);

                        var globalPoint:Point = _parentObject.localToGlobal(parentCoords);

                        var xp:Number = globalPoint.x + this._offSet;

                        var yp:Number;

                        if ((_hookEnabled &&globalPoint.y>this.height) || (!_hookEnabled &&globalPoint.y>this.height+10))

                        {

                                yp = globalPoint.y - this.height - 10;

                                if (! _hookEnabled)

                                {

                                        _hookEnabled = true;

                                        this.graphics.clear();

                                        drawBG();

                                }

                        }

                        else if (stage.stageHeight/2>this.height)

                        {

                                yp = globalPoint.y + 25;

                                if (_hookEnabled)

                                {

                                        _hookEnabled = false;

                                        this.graphics.clear();

                                        drawBG();

                                }

                        }

                        var overhangRight:Number = this._defaultWidth + xp;

                        if (overhangRight > stage.stageWidth)

                        {

                                xp = stage.stageWidth - this._defaultWidth;

                        }

                        if (xp < 0)

                        {

                                xp = 0;

                        }

                        if (yp < 0)

                        {

                                yp = 0;

                        }

                        this.x += ( xp - this.x ) / speed;

                        this.y += ( yp - this.y ) / speed;

                }



                private function addCopy( title:String, content:String ):void

                {

                        if (! this._titleOverride)

                        {

                                this.initTitleFormat();

                        }

                        var titleIsDevice:Boolean = this.isDeviceFont(_titleFormat);



                        this._tf = this.createField(titleIsDevice);

                        this._tf.htmlText = title;

                        this._tf.setTextFormat( this._titleFormat);

                        //this._tf.setTextFormat( this._titleFormat, 0, title.length );

                        if (this._autoSize)

                        {

                                this._defaultWidth = this._tf.textWidth + 4 + ( _buffer * 2 );

                        }

                        else

                        {

                                this._tf.width = this._defaultWidth - ( _buffer * 2 );

                        }



                        this._tf.x = this._tf.y = this._buffer;

                        this.textGlow( this._tf );

                        addChild( this._tf );

                        if (content != null)

                        {

                                if (! this._contentOverride)

                                {

                                        this.initContentFormat();

                                }

                                //check for device font

                                var contentIsDevice:Boolean = this.isDeviceFont(_contentFormat);

                                this._cf = this.createField(contentIsDevice);

                                this._cf.htmlText = content;

                                var bounds:Rectangle = this.getBounds(this);

                                this._cf.x = this._buffer;

                                this._cf.y = bounds.height + 5;

                                this.textGlow( this._cf );

                                this._cf.setTextFormat( this._contentFormat );

                                if (this._autoSize)

                                {

                                        var cfWidth:Number = this._cf.textWidth + 4 + ( _buffer * 2 );

                                        this._defaultWidth = cfWidth > this._defaultWidth ? cfWidth:this._defaultWidth;

                                }

                                else

                                {

                                        this._cf.width = this._defaultWidth - ( _buffer * 2 );

                                }

                                addChild( this._cf );

                        }

                }



                //create field, if not device font, set embed to true

                private function createField( deviceFont:Boolean ):TextField

                {

                        var tf:TextField = new TextField();

                        tf.embedFonts = ! deviceFont;

                        tf.gridFitType = "pixel";

                        //tf.border = true;

                        tf.autoSize = TextFieldAutoSize.LEFT;

                        tf.selectable = false;

                        if (! this._autoSize)

                        {

                                tf.multiline = true;

                                tf.wordWrap = true;

                        }

                        return tf;

                }



                //draw background, use drawing api if we need a hook

                private function drawBG():void

                {

                        var bounds:Rectangle = this.getBounds(this);

                        var fillType:String = GradientType.LINEAR;

                        //var colors:Array = [0xFFFFFF, 0x9C9C9C];

                        var alphas:Array = [1,1];

                        var ratios:Array = [0x00,0xFF];

                        var matr:Matrix = new Matrix();

                        var radians:Number = 90 * Math.PI / 180;

                        matr.createGradientBox(this._defaultWidth, bounds.height + ( this._buffer * 2 ), radians, 0, 0);

                        var spreadMethod:String = SpreadMethod.PAD;

                        this.graphics.beginGradientFill(fillType, this._bgColors, alphas, ratios, matr, spreadMethod);

                        if (this._hookEnabled)

                        {

                                var xp:Number = 0;

                                var yp:Number = 0;

                                var w:Number = this._defaultWidth;

                                var h:Number = bounds.height + ( this._buffer * 2 );

                                this.graphics.moveTo( xp + this._cornerRadius, yp );

                                this.graphics.lineTo( xp + w - this._cornerRadius, yp );

                                this.graphics.curveTo( xp + w, yp, xp + w, yp + this._cornerRadius );

                                this.graphics.lineTo( xp + w, yp + h - this._cornerRadius );

                                this.graphics.curveTo( xp + w, yp + h, xp + w - this._cornerRadius, yp + h );



                                //hook

                                this.graphics.lineTo( xp + this._hookOffSet + this._hookSize, yp + h );

                                this.graphics.lineTo( xp + this._hookOffSet , yp + h + this._hookSize );

                                this.graphics.lineTo( xp + this._hookOffSet - this._hookSize, yp + h );

                                this.graphics.lineTo( xp + this._cornerRadius, yp + h );



                                this.graphics.curveTo( xp, yp + h, xp, yp + h - this._cornerRadius );

                                this.graphics.lineTo( xp, yp + this._cornerRadius );

                                this.graphics.curveTo( xp, yp, xp + this._cornerRadius, yp );

                                this.graphics.endFill();

                        }

                        else

                        {

                                this.graphics.drawRoundRect( 0, 0, this._defaultWidth, bounds.height + ( this._buffer * 2 ), this._cornerRadius );

                        }

                }









                /* Fade In / Out */



                private function animate( show:Boolean ):void

                {

                        var end:int = show == true ? 1:0;

                        _tween = new Tween(this,"alpha",Strong.easeOut,this.alpha,end,.5,true);

                        if (! show)

                        {

                                _tween.addEventListener( TweenEvent.MOTION_FINISH, onComplete );

                                //_timer.reset();

                        }

                }



                private function onComplete( event:TweenEvent ):void

                {

                        event.currentTarget.removeEventListener(event.type, arguments.callee);

                        this.cleanUp();

                }



                /* End Fade */









                /** Getters / Setters */



                public function set tipWidth( value:Number ):void

                {

                        this._defaultWidth = value;

                }



                public function set titleFormat( tf:TextFormat ):void

                {

                        this._titleFormat = tf;

                        if (this._titleFormat.font == null)

                        {

                                this._titleFormat.font = "_sans";

                        }

                        this._titleOverride = true;

                }



                public function set contentFormat( tf:TextFormat ):void

                {

                        this._contentFormat = tf;

                        if (this._contentFormat.font == null)

                        {

                                this._contentFormat.font = "_sans";

                        }

                        this._contentOverride = true;

                }



                public function set align( value:String ):void

                {

                        var a:String = value.toLowerCase();

                        var values:String = "right left center";

                        if (values.indexOf(value) == -1)

                        {

                                throw new Error(this + " : Invalid Align Property, options are: 'right', 'left' & 'center'");

                        }

                        else

                        {

                                this._align = a;

                        }

                }



                /*public function set delay( value:Number ):void {

                this._delay = value;

                this._timer.delay = value;

                }*/



                public function set hook( value:Boolean ):void

                {

                        this._hookEnabled = value;

                }



                public function set hookSize( value:Number ):void

                {

                        this._hookSize = value;

                }



                public function set cornerRadius( value:Number ):void

                {

                        this._cornerRadius = value;

                }



                public function set colors( colArray:Array ):void

                {

                        this._bgColors = colArray;

                }



                public function set autoSize( value:Boolean ):void

                {

                        this._autoSize = value;

                }





                /* End Getters / Setters */







                /* Cosmetic */



                private function textGlow( field:TextField ):void

                {//对显示对象应用发光效果

                        var color:Number = 0x000000;

                        var alpha:Number = 0.2;

                        var blurX:Number = 2;

                        var blurY:Number = 2;

                        var strength:Number = 1;

                        var inner:Boolean = false;

                        var knockout:Boolean = false;

                        var quality:Number = BitmapFilterQuality.HIGH;



                        var filter:GlowFilter = new GlowFilter(color,

                                                          alpha,

                                                          blurX,

                                                          blurY,

                                                          strength,

                                                          quality,

                                                          inner,

                                                          knockout);

                        var myFilters:Array = new Array();

                        myFilters.push(filter);

                        field.filters = myFilters;

                }



                private function bgGlow():void

                {//对显示对象应用发光效果

                        var color:Number = 0x000000;

                        var alpha:Number = 0.40;

                        var blurX:Number = 2;

                        var blurY:Number = 2;

                        var strength:Number = 1;

                        var inner:Boolean = false;

                        var knockout:Boolean = false;

                        var quality:Number = BitmapFilterQuality.HIGH;



                        var filter:GlowFilter = new GlowFilter(color,

                                                          alpha,

                                                          blurX,

                                                          blurY,

                                                          strength,

                                                          quality,

                                                          inner,

                                                          knockout);

                        var myFilters:Array = new Array();

                        myFilters.push(filter);

                        filters = myFilters;

                }



                private function initTitleFormat():void

                {

                        _titleFormat = new TextFormat();

                        _titleFormat.font = "_sans";

                        _titleFormat.bold = true;

                        _titleFormat.size = 16;

                        _titleFormat.color = 0x01430E;

                }



                private function initContentFormat():void

                {

                        _contentFormat = new TextFormat();

                        _contentFormat.font = "_sans";

                        _contentFormat.bold = false;

                        _contentFormat.size = 14;

                        _contentFormat.color = 0x000000;

                }



                /* End Cosmetic */







                /* Helpers */



                /* Check if font is a device font */

                private function isDeviceFont( format:TextFormat ):Boolean

                {

                        var font:String = format.font;

                        var device:String = "_sans _serif _typewriter";

                        return device.indexOf( font ) > -1;

                        //_sans

                        //_serif

                        //_typewriter

                }



                private function setOffset():void

                {

                        switch ( this._align )

                        {

                                case "left" :

                                        this._offSet = - _defaultWidth +  ( _buffer * 3 ) + this._hookSize;

                                        this._hookOffSet = this._defaultWidth - ( _buffer * 3 ) - this._hookSize;

                                        break;



                                case "right" :

                                        this._offSet = 0 - ( _buffer * 3 ) - this._hookSize;

                                        this._hookOffSet = _buffer * 3 + this._hookSize;

                                        break;



                                case "center" :

                                        this._offSet = - ( _defaultWidth / 2 );

                                        this._hookOffSet =  ( _defaultWidth / 2 );

                                        break;



                                default :

                                        this._offSet = - ( _defaultWidth / 2 );

                                        this._hookOffSet =  ( _defaultWidth / 2 );

                                        break;

                        }

                }



                /* End Helpers */







                /* Clean */



                private function cleanUp():void

                {

                        this._parentObject.removeEventListener( MouseEvent.MOUSE_OUT, this.onMouseOut );

                        this.follow( false );

                        this._tf.filters = [];

                        this.filters = [];

                        removeChild( this._tf );

                        this._tf = null;

                        if (this._cf != null)

                        {

                                this._cf.filters = [];

                                removeChild( this._cf );

                        }

                        this.graphics.clear();

                        parent.removeChild( this );

                }



                /* End Clean */



        }

}