Category Archives: Uncategorized

iOS Jobs and Candidates

The goal of this post is to help connect some good iOS coders with contracts/jobs. I’ve been hearing a lot of interest in iOS development work from startups looking for either a consultant or a full-time employee. At the same time I do not know very many iOS developers who are available to work (including […]

The best talk at WWDC 11

I was happy to see that Apple had recently posted all the session videos from WWDC online, available for free to Apple developers. It’s great that they do this, because a lot of us *cough* aren’t able to attend for one reason or another, but we still want to know what’s going on. One talk […]

The Pulse Eng Blog: New Speed Analysis Tool

I just added a new tool to the moriarty library for app speed analysis. I wrote this tool while working at Pulse, so the post is on the Pulse Eng blog. Check it out. Some background: A few months ago I had the opportunity to contribute to the Pulse news reader app. This is a […]

Fast low-level arrays

Some apps need fast processing involving variable-length arrays. NSMutableArray is pretty efficient and easy-to-use, but it requires a lot of Objective-C overhead. In this post, I introduce CArray, a low-level, superfast framework for variable-length arrays. CArray is useful when: You’re working with C data types — pointers or primitive types or structs thereof; speed is […]

Repeating an animation at changing speeds

I recently came across the following problem: I wanted to handle a repeated animation that would continuously change its speed over time. In particular, I’m building a game with a flashing square, and I want it to flash more quickly if the player is getting closer to dying. Conceptually, this is very easy, and it’s […]


It’s surprisingly tricky just to draw a single line in iOS. Quartz has great 2D graphic support, but you need to dive down into that world and use many lines of code to draw one line. In some cases, you really just want a few well-placed lines to augment an elegant UI – this class […]

Wipe Transitions

I wrote a class today called WipeView that can provide a wipe transition to make any image disappear. Like everything else I post, it’s open-source (Apache 2 license), and I’ve added it to moriarty. Here’s a bottom-to-top example to see what this class can do: That’s the moon Europa (of Jupiter) vanishing there. This kind […]

Tracking basic app use

This post introduces the BNAppStats class which acts as a very light weight, extremely easy-to-use class for detecting how many times your app has run. Suppose you want to display a message only the first time your app is opened, or the first n times. Or perhaps you’d like to ask the user to rate […]

Want to beta test a game?

Readers, I will be posting less frequently for the next month or so, since I’m focusing my time on a puzzle game called Loop Twister that I’m creating for iPad and iPhone. I know, this is very sad news for you, who love to read my ever-useful tips on iOS coding. However, like the silver […]

An upgrade from UIColor

This post introduces the BNColor class, a versatile color object that can be easily changed, saved to disk, and offers live switching between HSV and RGB color spaces – all features that are missing from the built-in UIColor class. Sample code The easiest way to see what the class can do is by example: BNColor […]