The zero based index of the drawing operator text array item
that contains this fragment. For non text array operators this
value is zero.
Each TextFragment spans a part of a PDF stream drawing operator.
The part may be the entire of the text drawn by the operator or it
may be a section of the text within that operator.
Some text drawing operators allow multiple items of text to be
drawn. This provides a useful shorthand to allow character
placement to be adjusted within a string. For example the following
command will draw two items of text with a wide space (specified by
the number) between the words.
[ (Breaking) 4000 (Bad) ] TJ
Each TextFragment only corresponds to one of the strings within
such an array. This property is a zero based index which tells you
which one. For example in the above example, if the TextFragment
corresponded to "Bad", then the TextSpanIndex would be equal to
For text drawing operations which do not involve arrays this
value will always be zero.