The XAccessibleText interface should be implemented by
all UNO components that present textual information on the display like
buttons, text entry fields, or text portions of the document window.
The interface provides access to the text's content, attributes, and
spatial location. However, text can not be modified with this
interface. That is the task of the XAccessibleEditableText
interface.
The text length, i.e. the number of characters in the text, is
returned by getCharacterCount.
All methods that operate on particular characters (e.g.
getCharacterAt) use character
indices from 0 to length-1. All methods that operate on character
positions (e.g. getTextRange)
use indices from 0 to length.
Please note that accessible text does not necessarily support
selection. In this case it should behave as if there where no
selection. An empty selection is used for example to express the
current cursor position.