Three20: Open source components for iPhone developers
Joe Hewitt, original author of the Firebug Firefox extension, has announced the Three20 project, an Apache 2.0 licensed open source library of components for developing iPhone applications. The project's name is a reference to the 320 pixel wide screen of the iPhone.
Major components of Three20 include a PhotoView controller, which lets developers plug in their own image sources and supports loading on demand over the network, a Message Composer, which simulates the Apple mail composer screen, and a Web Image viewer, to make image display as simple as supplying a URL. Other components include better text fields, a URL requester which caches to disk, a NavigationCenter component for arranging an application as pages and internet aware table views and data sources.
Three20 has been developed from code Hewitt has developed for his open source Facebook Connect for iPhone application. Over the past few weeks, he has been re-factoring the useful components in the Facebook application into stand alone static libraries. Hewitt describes the code as alpha-quality, as much of it has been rewritten during the re-factoring process, but he plans to develop Facebook for iPhone 3.0 using Three20 and believes that should see the code become stable by May.
Three20 is available on github for interested developers.