Outlet Collections

A quick post to explain my tweet.

TL;DR: I can batch show and hide UIViews really easily now. Easier than setting up a bunch of outlets, fiddling with tags, making dummy views, or groveling through the view hierarchy.

I bet it’s Cocoa 101 nowadays, but they were new to me, pretty much seeing the reference when dragging a connection to header files (which I never do) and promptly forgetting about them. I might have seen reference to them in a WWDC sessions or something. But finally now I had a real use. Yay! For a lot of this stuff I need to actually use it for Something Real before it sticks in my brain. I can learn stuff by doing, but I’m lousy at memorization. Just look at my history grades during high school. On second thought, please don’t.

RideBuddy™ is one of the new apps coming from Cycling Fusion. Amongst a ton of other stuff, RideBuddy lets you track workout time in various heart zones – ranges of heart rates that have different benefits and consequences to the body. We like the Sally Edwards Heart Zones® system, which is a five-zone system based on certain physiological markers. I won’t get into specifics here, you can join the Cycling Fusion Winter Training in January and get the full details.

Five zones are kind of a lot for a beginner or just a casual rider to wrap their mind around, so Sally created Zoning™, a friendlier three-zone system and a color-coded heart rate monitor. It’s only three zones, but it’s based on the same physiological markers as the five-zone system. You can get a lot of health and training benefit by using the three zone system, and can graduate to the five-zone system when you feel up to it.

My stuff needs to support both. So, I have a number of screens like this one:

Something that’ll support three zones or five zones. Internally I can support from one to five zones. The code that adjusts the layouts based on the zone system in-use hides everything zone-related, then populates and enables stuff zone-by-zone until it runs out of zones. In the above screenie I have four objects per zone: two static labels and two text fields. zone zone zone.

To simplify that work, I have five IBOutletCollection(UIView)s — one for each zone. I walk through all of them to Hide All The Things, then walk the zones enabling a particular collection and populating items until I run out of zones. If I don’t hit a collection, it stays hidden.

Understandably, this is so much nicer than setting up an IBOutlet for each label and text field and making the connections. Or setting a tag on the items. Or groveling through the view hierarchy showing and hiding things. Or having a dummy UIView just to be a container. Just add the outlet collection and make connections in IB.

Markus Möller on Twitter “uses them for animating / moving groups of views. Better than putting them all in a container view. Less hierarchy.” which is another excellent use.

 

My First App: Class Builder

My first App got accepted into the AppStore yesterday – Cycling Fusion’s Class Builder™. Woot! Amazingly enough, it went through the approval process without a peep. There’s screen shots and tutorial videos (some still in the making – didn’t expect AppStore approval so quickly) at the link. And it’s at the AppStore.

Class Builder is a tool for Indoor Cycling (a.k.a. “Spinning®”) instructors to lead better classes. Rather than juggling an ipod, sheets of paper or 3×5 cards, and a stopwatch; instructors can plug their Device into the club sound system, run the class, and have cues pop up at the proper time during the class. They can also configure pre-class and post-class music for ambience before and afterwards. If the club has a projector, the instructor can plug their Device into the projector and show everyone the ride profile, along with additional information like current cadence / power / HeartZone®. A slideshow of photos can be shown during the pre-class time to help set the mood.

Despite “Class” in the name, this has nothing to do with programming.

Folks have asked me what I’ve been up to in the year-and-change since I left Google to work with Cycling Fusion. This is it, and the usual billion other things that go on when you work at a startup (along with the major update to AMOSXP)

The code is pretty much all mine, end-to-end. 13,000 non-comment / non-whitespace / non-brace LoC, 84 classes, 32 html files, and 677 .pngs. Not huge, but respectable. It was my first time really to work on something small enough that could be coded by a single programmer – usually I work on behind-the-scenes stuff that nobody else wants to touch. App design was by me and Gene Nacey, the fearless leader of Cycling Fusion. Graphic design by Emanuel Rufino and me. Luckily I now have the Photoshop skills to convert between an inspired artist and the user interface, to tone things down or amp them up as needed to fit the demands of the UI.

Class Builder is a part of the overall Cycling Fusion strategy for bringing the worlds of Indoor and Outdoor cycling together. We’re revolutionizing Indoor Cycling as we now know it through curriculum and certification, targeted training programs, web-based tools, mobile device apps, licensable music and an online video training library. Our big coming-out party is in the fall. If you’re into that kind of stuff, come on down to the ICI Pro Conference in October and check us out.

Learning iPhone in Pittsburgh

The Pittsburgh CocoaHeads (where it all started) are going to be working through the new edition of the Dave Mark / Jeff Lamarche / Jack Nutting iPhone book as a group (ebook available today! woo!). Our regular monthly meetings will have a kick-off presentation on what to expect the next month. We figure a chapter a week is a good pace for folks with busy lifestyles.

A couple of us are making ourselves available for “office hours” if folks have questions / get stuck. Huge gumption traps for beginners are compiler errors and basic memory management, things that programmers with more experience can just glance at and know exactly what’s wrong. We’re hoping this solves the “stall-out half-way through” problem many people have picking up new technology as a hobby.

I had the pleasure of being the Tech Reviewer for this updated edition of Beginning iPhone4 Development. There’s a lot of good cool new stuff in there. During the course of discussions with Apress about acquiring the book in time for our launch, they’ve made a CocoaHeads discount code good for 25% off Mac/Phone ebook titles until the end of March : APRESSCOCOAHEADS2011, when you get it from the Apress store. There’s also a discount for folks who already have the iPhone3 version of the book, but I don’t know if they stack.

More info is available at http://bit.ly/pgh-iphone, especially if you’re in the Pittsburgh area. Come join us! Folks outside of Pittsburgh are welcome to do the same thing. Feel free to use the monthly kick-off slides, which I’ll be putting up at http://borkware.com/cocoaheads as we progress into the year.

Making Command-Line Tools

Just in case you’re reading Learn Objective-C on the Macintosh, and you’re wanting to make a “Foundation Command-Line Utility” project in the might (or might not) be new Xcode which might (or might not) be associated with the latest iPhone excitement, you’ll probably want to look under “Command Line Utility” on the sidebar, and choose “Foundation Tool” from the project picker. They may (or may not) have moved it from previous Xcode versions. Or not. You didn’t hear it from me,

Learn Objective-C… on the iPhone?

I usually don’t like to Pimp my own Warez, but Sir Daniel Punkass pointed out to me that Learn Objective-C on the Macintosh is quite applicable to iPhone development, especially for folks who don’t already know Objective-C. Sometimes I’m a bit clueless.

LoC is an introductory book, but assumes you know C (it’s officially the follow-on to Learn C On the Macintosh). It covers a lot of the basic stuff you need in Cloud-Cocoa Land – especially memory management, which we go over a lot in the latter half of the book, since memory management is the place that many Cocoa programmers have problems.

We tried to make it as non-boring as possible, so I think even experienced programmers can get something out of it. From a twitter in response to Mr. Punkass, Diego wrote “started on the book and it’s very good. straight to the point and doesn’t linger on topics. which i like. thanks for the tip” (Thanks Diego!)

On the down-side, it doesn’t cover the properties syntax, or the new fast enumeration syntax, but once you have the basics of the language under your belt, you should be able to pick those up quickly.