Adding annotation on zoomed pdf


I am struggling to add annotations to a pdf document that has been zoomed in iOS.
I only get the coordinates of the screen rather than the document on touch, so the positioning is wrong.
Is there a function that returns the true document coordinates where the user has clicked/touched?

Best Regards

Normally you would use the Tools framework, as this takes care of everything for you.

If don’t want to use it, you should still use the code there as a guideline for writing your own.

In particular the Tools code shows how to user PDFViewCtrl ConvScreenPtToPagePt

Tools code also shows how to acquire and release a Write Lock, which you need to do if the document is also being viewed. If you don’t get the write lock you could cause undefined behaviour.