FAQ.text

TextArea, TextInput, Label, Text (all in the mx.controls package) all use mx.core.UITextField to render text. If there was a method that you wish were in one of these text controls, it may be in flash.text.TextField (which is the grandparent of UITextField). There is a lot of information about how text operates in flash under "flash.text.TextField" on this site. But before you look through the undocumented features (see the navigation menu to your right), check the documented ones here. Documented highlights include:

getCharBoundries, getCharIndexAtPoint, getFirstCharInParagraph, getLineIndexAtPoint, getLineIndexOfChar, getLineLength, getLineMetrics, getLineOffset, getLineText, getParagraphLength

You can access the UITextField of these mx controls by extending the control and accessing the protected textField property or you can call mx_internal::getTextField(). See mx.core.mx_internal for how the later works.