getLineStartPosition(line: Integer): Integer;
The getLineStartPosition method of the JadeTextEdit class returns the zero-based character offset of the first character in the line specified in the line parameter.
If the specified line number is less than 1, this method returns the character offset of the start of the line that contains the start of the current selection. If the specified line number is greater than the number of lines in the text editor, it returns -1.