How can I implement zoom-in and auto center on some PDF content?

Q: I would like to be able to click on a paragraph and have it zoom in
and auto center.

I'm looking for an easy approach to zooming in on content (one click
or motion if possible).

Also would like to create a bookmark based on the position and zoom of
the content.
A: You may want to take a look at 'CustomToolMode.e_zoomin' custom
tool that is implemented in PDFView sample project for .NET (i.e.

Using the same approach (i.e. by calling pdfview.SetCurrentPage() and
pdfview.SetZoom(x, y, zoom)) you should be able zoom in and center on
part or a given PDF page.

The only remaining issue is how do you get the positioning information
for a given word or a block of text. This information can be obtained
using pdftron.PDF.TextExtractor class (as shown in TextExtract sample
project -