iPhone development: No walk in the park

Craig Hockenberry's MobieTwitterriffic UI in development Illustrious Twitterrific developer and general nice fella, Craig Hockenberry, has recently mused on his efforts to create a pre-SDK iPhone port called MobileTwitterrific. And his warning to developers is, "Don't expect to reuse much of your existing code."

Discussing on his blog the revelations gleaned from using the APIs available on the iPhone, Hockenberry had a laundry list of caveats for those itching to crack in to the highly-anticipated SDK expected later this month.

His main points, however, boil down to the fact that the iPhone is a small mobile device with limits that are much tighter than a typical desktop device. For example, while making NIBs using Interface Builder is easy for developers, it relies on the processing power and memory that desktops have to make it work behind the scenes. The iPhone doesn't have the same amount of memory and processor power to throw around willy-nilly. So, no NIBs. You'll be laying out UIViews the old fashioned way: with a text editor.

In another "throwback" to programming's golden age, developers have to pay more attention to memory management. Remember when 128k was more memory than any sane person could use? Well, probably not, but I do. The iPhone just doesn't have gigabytes of memory to throw at a complex UI. And speaking of complexity, Hockenberry suggests getting rid of as much as possible. "One mental exercise that I've found useful is to ask myself 'Will I need this feature while walking down the street or sitting in traffic?'"

The iPhone is in many ways radically different than desktops, and this will require more radical thinking about how apps are developed. If you've got Cocoa experience, that will get you halfway there. But it might be time to dust off your old algorithms book and brush up on your big-O analysis. And while you're at it, start imagining clicking everything with one finger while walking down the street drinking a latte. Because that is what your users are going to be doing.