- text
- The text the TextView is displaying
- start
- The offset of the start of the range of the text that was modified
- lengthBefore
- The length of the former text that has been replaced
- lengthAfter
- The length of the replacement modified text
This method is called when the text is changed, in case any subclasses would like to know. Within text, the lengthAfter characters beginning at start have just replaced old text that had length lengthBefore. It is an error to attempt to make changes to text from this callback.