监听TextArea的link事件

      在Flex中打开另一个页面有多种方法，比如navigateToURL，又比如用组件的htmltext属性，通过超链接< a href="">的方式等。用navigateToURL时有限制条件，即装载swf的html容器的allowNetworking属性必须设置为all,否则会禁用该api，但是现实开发中，很多时候我们是把Flex成品以swf的形式嵌入到html中，一不留神我们或者别人很可能会把这个属性给限制掉。至于超链接的方式，毕竟我们是让别人去帮我们打开另一个页面，它的前置事件我们没办法去操控，只能去监听链接完的事件，而且监听链接事件还有特定的条件，即你必须是在链接前加上"event:"前缀< a href="event:www.google.com"/>，然后在link事件中再调用navigateToURL把链接打开。

      近日项目中恰好遇到点击TextArea的文本，打开另一个页面的需求，为了不受外部条件allowNetworking的控制（项目是以swf的形式嵌入在别人的网页里边），只好采取超链接的解决方案，但是又需要在link事件中作自己的处理，鉴于以上条件，TextArea已经不够用，本想自己重写，但网上已经有高手做了相关处理，甚欢，直接拿来用了：

自定义TextArea:

/*Copyright (c) 2008 Robert L Sheely, Inc.Permission is hereby granted, free of charge, to any personobtaining a copy of this software and associated documentationfiles (the "Software"), to deal in the Software withoutrestriction, including without limitation the rights to use,copy, modify, merge, publish, distribute, sublicense, and/or sellcopies of the Software, and to permit persons to whom theSoftware is furnished to do so, subject to the followingconditions:The above copyright notice and this permission notice shall beincluded in all copies or substantial portions of the Software.THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIESOF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE ANDNONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHTHOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISINGFROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OROTHER DEALINGS IN THE SOFTWARE.*/package com.robsheely.text{import flash.events.Event;import flash.events.MouseEvent;import flash.events.TextEvent;import mx.core.mx_internal;import mx.core.UITextField;import mx.controls.TextArea;import mx.controls.textClasses.TextRange;import mx.events.FlexEvent;use namespace mx_internal;public class LinkTextArea extends TextArea{public function LinkTextArea(){super();addEventListener(FlexEvent.CREATION_COMPLETE, onCreationComplete);}protected function onCreationComplete(pEvent:FlexEvent):void{selectable = false;}// Override the electable property so we can turn our custom onclick handler// on if selectable is set to true. If it's set to false, we remove the// listener so the text area can handle things as usual.override public function set selectable(pSelectable:Boolean):void{super.selectable = pSelectable;if (textField){textField.selectable = pSelectable;}else{// If we're attempting to set selectable before the component// has completed its instantiation, we need to postpone// passing the command on to the textField (which won't have// been created yet) until instantiation has completed.callLater(function(pSelectable:Boolean):void{textField.selectable = pSelectable;}, [pSelectable]);}if (!pSelectable){addEventListener(MouseEvent.CLICK, onClick);}else{UITextField(textField).setSelection(-1, -1);removeEventListener(MouseEvent.CLICK, onClick);}}protected function onClick(pEvent:MouseEvent):void{// Find the letter under our clickvar index:int = textField.getCharIndexAtPoint(pEvent.localX, pEvent.localY);if (index != -1){// convert the letter to a text range so we can extract the urlvar range:TextRange = new TextRange(this, false, index, index + 1);// make sure it contains a urlif (range.url.length > 0){// if the text area is not editable, select the letterif (!editable){UITextField(textField).setSelection(index, index + 1);}// The normal click event strips out the 'event;' portion of the url.// So to be consistent, let's strip it out, too.var url:String = range.url;if (url.substr(0, 6) == 'event:'){url = url.substring(6);}// Manually dispatch the link event with the url neatly includeddispatchEvent(new TextEvent(TextEvent.LINK, false, false, url));// unselect the letterif (!editable){UITextField(textField).setSelection(-1, -1);}}}}}} 

Test code:

<?xml version="1.0" encoding="utf-8"?><mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"xmlns:l="com.robsheely.text.*"layout="vertical" horizontalAlign="center"><mx:Script><!--[CDATA[import mx.controls.Alert;import mx.collections.ArrayCollection;[Bindable]private var pd:ArrayCollection = new ArrayCollection();//规范查看监听事件private function helpPageLinked(event:TextEvent):void {trace("-------------linked******");if(event.text == "http://www.baidu.com"){navigateToURL(new URLRequest(event.text),"_blank")}Alert.show(event.target.toString() +" has linked");}]]></mx:Script><mx:TextArea width="100%" height="50" link="helpPageLinked(event)" ><mx:htmlText> <![CDATA[Hello,how are you doing these days?<a href="event:http://www.google.com" mce_href="event://http//www.google.com" target="_blank"><font color="#DC0505">Couldn't be better</font></a>]]></mx:htmlText> </mx:TextArea><l:LinkTextArea id="normInfo" width="100%" height="50" link="helpPageLinked(event)" ><l:htmlText> <![CDATA[Come on you guys!<a href="gg.html" mce_href="gg.html" target="_blank"><font color="#DC0505">Enter</font></a>]]></l:htmlText></l:LinkTextArea><mx:Label selectable="true" link="helpPageLinked(event);"> <mx:htmlText> <![CDATA[<a href="event:http://www.baidu.com" mce_href="event://http//www.baidu.com">Navigate to Baidu.com.</a>]]--> </mx:htmlText> </mx:Label> </mx:Application>