Gets delimited text from an Text object which precedes a given text offset.
this |
a pointer to the Text object on which to operate. |
offset |
a int indicating the offset from which the delimiter search is based. |
type |
an TextBoundaryType indicating whether the desired text string is a word, sentence, line, or attribute run. |
an TextRange containing a UTF-8 string representing the delimited text, both of whose delimiting boundaries are before the current offset, or an empty string if no such text exists. |