getLineNumberAt abstract method
- int codeUnitOffset
Returns the line number of the line that contains the code unit that
codeUnitOffset points to.
This method returns null if the given codeUnitOffset is out of bounds, or
is logically after the last visible codepoint. This includes the case where
its codepoint belongs to a visible line, but the text layout library
replaced it with an ellipsis.
If the target code unit points to a control character that introduces
mandatory line breaks (most notably the line feed character LF, typically
represented in strings as the escape sequence "\n"), to conform to
the unicode rules, the control
character itself is always considered to be at the end of "current" line
rather than the beginning of the new line.
Implementation
int? getLineNumberAt(int codeUnitOffset);