Things that were not immediately obvious to me

In my Fightcard application, I had to implement a lot of “picker” screens – screens that essentially let the user select one of a list of options, much as a drop-down does in a conventional GUI. Since the behavior of all these screens was so similar, I opted to create a common ChoiceMenu class. I now present it for your consideration.

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Today, a quick guide through basic location services on the iPhone 3G (i.e. I’m not handling heading information here.) I run through a quick overview of the steps involved in building a basic location-aware app, and provide a complete Xcode project for your perusal.

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I’m pleased to announce that Apple has approved my very first “real” iPhone application: Fightcard. This app implements a boxing scorecard (also suitable, I guess, for MMA on the 10-point-must system) that allows you to systematically and properly score a fight. With all the controversy this year (e.g. Cotto-Clottey and Malignaggi-Diaz), it’s a better time than ever to start scoring the fights yourself.

Fightcard permanently records your round-by-round scores for all fights. Rounds are scored on:

• Clean, Effective Punching
• Defense
• Ring Generalship
• Effective Aggression
• Knockdowns
• Point Deductions

Fightcard offers full support for all stoppage scenarios: KOs, TKOs, No Decisions, Technical Decisions, etc. You should buy a copy right now.

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The iPhone makes the database underlying it’s built-in Contacts application available through a framework. This is handy, for two reasons:

• If you want to let the user contact people from inside your app, it’s a good idea to make it easy for the user to search his address book.
• If your app stores contact information, it’s a good idea to store it (when possible) in the main address book, which is backed up, and possibly synchronized with the address books in other applications.

The framework’s API is pretty simple, but I want to mention a few non-ovious aspects of it, as well as one bug, that I encountered while working with groups.

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We’ve been talking about some Core Graphics trickery recently, related either to fancy gradients used to create shiny buttons, or complicated clipping. I wanted to take a moment to time some of this stuff out on the iPhone, and see if there were any performance implications. There don’t seem to be.

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I want to revisit Tuesday’s discussion of clipping; when I wrote that post I was laboring under certain misconceptions related to Core Graphics paths, which I would like to discuss. As a consequence of correcting these misconceptions, I can see that Core Graphics clipping is much easier to work with than I had supposed.

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