iText in Action, Second Edition

Chapter 15. Page content and structure

This chapter covers

• Making content optional
• Working with marked content
• Parsing PDF files

The previous chapter was devoted entirely to page content; you learned how to add content the PDF way and the Java way. We’ll continue discussing content in this chapter. We’ll add operators and operands to make part of the content optional. We’ll use marked content to add custom parameters to graphical objects, to make the content accessible for the visually impaired, and to store the structure of the document. Finally, we’ll make a fair attempt at parsing a PDF document and extracting content from a page.

15.1. Making content visible or invisible

All the content you’ve added to a page so far was either visible ...