Then, in the following files, you need to edit the following statements during ARC refactoring to use plain __bridge casts:

ReaderDocument.m:
... = [NSString stringWithString:(__bridge id)theString];

ReaderThumbFetch.m:
... = CGImageSourceCreateWithURL((__bridge CFURLRef)thumbURL, NULL);

After ARC refactoring, it is safe to remove the various “ivar = nil;” statements in the various class dealloc methods (and delete them if they are empty).

• Now loads and decodes thumbnail PNGs on a background thread.
• Added READER_DISABLE_RETINA #define performance option.
• Some performance improvements on iPad 3rd generation.
• Bug fix to PDF link handling with cropboxed PDF files.
• Handles PDF web links without http:// as the prefix.
• Tested under Xcode 4.3.2 and iOS 5.1.

• Replaced UIToolbars with custom toolbars.
• Some more assorted bug fixes and tweaks.

• Added page thumbnail document navigation.
• Added support for page bookmarks.

• A medium resolution page preview image is now shown first.
• The page bar now uses small page thumbs instead of a simple slider.
• Added password handling to ReaderDocument plist unarchive.

• Added PDF link (URI and page target) support.
• Assorted code cleanup, optimizations and bug fixes.
• Fixed rotation handling when in a UITabBarController.

I’ve crafted this open source PDF reader/viewer for fellow iOS developers struggling with wrangling PDF files onto iOS device screens.

The code is universal and does not require any XIBs (as all UI elements are code generated, allowing for greatest flexibility). It runs on iPad, iPhone and iPod touch with iOS 4.0 and up. Also supported are the Retina displays in all new devices and is ready to be fully internationalized. The idea was to provide a complete project template that you could start building from, or, just pull the required files into an existing project to enable PDF reading/viewing in your app(s).

Document navigation is very similar to iBooks: After launching the sample app, tap on the left hand side of the screen to go back a page. Tap on the right hand side to go to the next page. You can also swipe left and right to change pages. Tap on the screen to fade in the toolbar and page slider. Double-tap with one finger (or pinch out) to zoom in. Double tap with two fingers (or pinch in) to zoom out.

This implementation has been tested with large PDF files (over 250MB in size and over 2800 pages in length) and with PDF files of all flavors (from text only documents to graphics heavy magazines). It also works rather well on older devices (such as the iPod touch 2nd generation and iPhone 3G) and takes advantage of the dual-core processor (via CATiledLayer and multi-threading) in new devices.

The overall PDF reader/viewer functionality is encapsulated in the ReaderViewController class. To present a document with this class, you first need to create a ReaderDocument object with the file path to the PDF document and then initialize a new ReaderViewController with this ReaderDocument object. The ReaderViewController class uses a ReaderDocument object to store information about the document and to keep track of document properties (thumb cache directory path, bookmarks and the current page number for example).

An initialized ReaderViewController can then be presented modally, pushed onto a UINavigationController stack, placed in a UITabBarController tab, or be used as a root view controller. Please note that since ReaderViewController implements its own toolbar, you need to hide the UINavigationController navigation bar before pushing it and then show the navigation bar after popping it. The ReaderDemoController class shows how this is done with a bundled PDF file. To create a ‘book as an app’, have a look at the ReaderBookDelegate class.

Please see the README file for more details and information.

Revised 2012-04-14