Objective-C: How to implement TextView orphan control

I'm working on an iPad app that does a simple display of text similar to iBooks.

I would like to display ONLY full paragraphs on each screen (ie, no orphan/widows on a page). Similar to iBooks, I want to allow the user to change the font and font size and continue to keep all lines in paragraphs together. The user will be able to page forward and backwards (just like iBooks).

I've been researching this and can't find a solution for this. I would think that someone has already done this code, but it looks like I'm going to have to figure out the point size of the font and calculate the size of the TextView and then count how many characters, etc etc etc.

Does anyone have a suggestion where I might st开发者_如何学Goart to do this?

Thanks a bunch!

Look at the NSString UIKit Addition it has methods for calculating how much space the rendering of string in a give font will take.