The following example shows how you can left, center, right, or fully justify a block of text in the Flex TextArea control by setting the textAlign style.
Full code after the jump.
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/03/08/setting-the-text-alignment-in-a-textarea-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="middle"
backgroundColor="white">
<mx:Script>
<![CDATA[
import mx.events.ItemClickEvent;
private function toggleButtonBar_itemClick(evt:ItemClickEvent):void {
textArea.setStyle("textAlign", evt.label);
}
]]>
</mx:Script>
<mx:Array id="arr">
<mx:String>left</mx:String>
<mx:String>center</mx:String>
<mx:String>right</mx:String>
<mx:String>justify</mx:String>
</mx:Array>
<mx:String id="lorem" source="lorem.txt" />
<mx:ApplicationControlBar dock="true">
<mx:Form styleName="plain">
<mx:FormItem label="textAlign:">
<mx:ToggleButtonBar id="toggleButtonBar"
dataProvider="{arr}"
selectedIndex="0"
itemClick="toggleButtonBar_itemClick(event);" />
</mx:FormItem>
</mx:Form>
</mx:ApplicationControlBar>
<mx:TextArea id="textArea"
text="{lorem}"
textAlign="left"
width="100%"
height="100%" />
</mx:Application>
View source is enabled in the following example.





Note: According to the Flex documetation (for both Flex 2 and 3) the only valid settings for the textAlign style are left, right and center. Indeed, in Flex Builder these are the only options that are presented when using auto-complete. As demonstrated in the example, however, justify does actually work as expected.