WWDC – Grey Patterson

I’m writing this a bit after WWDC has ended, and publishing it a bit further after that, so pardon the tardiness as I share my thoughts, in no particular order:

As a user, I am quite excited by the new functionality in FaceTime, and the new Focus system for managing notifications. The system of tiered notifications looks great, and I’m excited for the, oh, 15 minutes most people will have between ‘installing iOS 15’ and ‘an app first abusing the notification level to send them spam.’¹ In iOS 16, can we get a “report notification as spam” button that immediately flags the app for App Review to yell at?
As both a developer and user, I was immensely excited to see the ManagedSettings and ManagedSettingsUI frameworks – I really like the concept of Screen Time for externalized self-control, and being able to use custom implementations or build my own seemed like a dream.² Unfortunately, all those dreams were immediately crushed by the reveal that this all requires FamilyControls, so not only can I not do anything interesting with it as a developer, I can’t even use it myself. Because, as we all know, the only use case for “my phone won’t let me use it to waste time” is “parents managing their children.”
Swift’s implementation of async/await looks great, and the stuff Apple’s doing with @MainActor seems to have met the goal of “the language eliminates an entire class of error” that initially gave us optionals, so I’m quite happy about that. I hope Vapor updates to async/await soon, I’d love to untangle some of my flatMap chains.
The new Human Interface Guidelines section on Inclusion is very well-written and hits on some important points.
I am incredibly excited about the virtual KVM thing coming to macOS and iPadOS – my desk setup features two monitors for macOS, and an iPad perpetually on the side, and the idea of being able to control the iPad without taking my hands off the main keyboard and mouse is very exciting.³
Safari on iOS got support for web extensions, which is neat. I also like that they’re pulling things down toward the bottom of the screen, should be more reachable.
Safari on macOS might finally do something that Mozilla never managed to do: convince me to switch to Firefox. I sincerely hope this is the peak of “aesthetics over functionality” in Apple’s design, and that it gets better from here, because this is a mess: lower contrast text, the core UI element moves around all the time so you can’t have any muscle memory, and they’ve buried every single button behind a ‘more’ menu.
SwiftUI got lots of little updates, but the thing that I may be most excited about is the simple quality of life improvements as a result of SE-299 – .listStyle(.insetGrouped) is much easier to type than .listStyle(InsetGroupedListStyle()), especially considering that Xcode can actually suggest .insetGrouped.

In my case, it’ll probably be a couple days, and then Apple Music will punch through a Focus mode to notify me that Billie Eilish has a new single or something. ↩
I already have a name for the app I want to build using these API. My first feature would just be “the existing Screen Time system, but it actually knows how time works.” Something like 90% of the time that I hit ‘one more minute’ I’m instead given a couple seconds. Apple, I know that time is hard, but it isn’t that hard. ↩
Why the iPad? Because iPadOS is sandboxed, which limits the sort of bugs that Teams can introduce and evil that Zoom can. Sure, they both have macOS apps – but you shouldn’t install either of them. ↩

A few days ago, Apple announced the winners of their Swift Student Challenge. I had applied and used my “taking a test” tactic, which was to hit ‘submit’ and then promptly erase the whole thing from my brain. (What’s done is done, and I feel silly worrying about something I have no control over.)

So when I got the email that “my status was updated” it was a bit of a surprise.

And when I clicked through the link (because, of course, they can’t just say in the email, you have to sign in) I was in for more of a surprise.

My submission had been accepted. I’m one of 350 students around the world whose work sufficiently impressed the judges at Apple.

Screenshot from Apple Developer website. It reads: Congratulations! Your submission has been selected for a WWDC20 Swift Student Challenge award. You'll receive an exclusive WWDC20 jacket and pin set at the mailing address you provided on your submission form. You'll also be able to download pre-release software, request lab appointments, and connect with Apple engineers over WWDC20 content on the forums. In addition, one year of individual membership in the Apple Developer Program will be assigned free of charge to eligible accounts of recipients who have reached the age of majority in their region. For details, see the WWDC20 Swift Student Challenge Terms and Conditions. — Neat!

Now, throughout the whole process of applying, I was my usual secretive self. I think two people knew that I was applying at all, much less what I was working on. Since it’s over with, though, it’s time for the unveiling.

What I made

I wanted to bring back a concept I’ve played with before: cellular automata. A few days before the competition was announced, I’d seen a video that really caught my interest.

Well hey, I thought, I’ve got some code for running cellular automata. I want to learn Swift Playgrounds. And I’ve been having fun with SwiftUI. Let’s combine those things, shall we?

The first big change was a visual history; when a cell dies, I don’t want it to just go out, I want it to fade slowly, leaving behind a trail of where the automata have spread.

The second was rewriting all the visuals in SwiftUI, which was a fun project. Animation timings took me a bit to get right, as did figuring out how to do an automated ‘update n times a second’ in Combine. The biggest issue I had, actually, was performance – I had to do some fun little tricks to get it to run smoothly. (Note the .drawingGroup() here – that made a big difference.)

And third, I didn’t want it to just be “here’s some code, look how pretty,” I wanted to actually use the Playground format to show some cool stuff. This turned out to be the most frustrating part of the whole thing – the Swift Playgrounds app doesn’t actually support creating a PlaygroundBook, and the Xcode template wasn’t supported in the then-current version of Xcode.

But the end result? Oh, I’m quite happy with it. PlaygroundBooks are cool once you get past how un-documented they are. You can, to borrow a Jupyter turn of phrase, mix code and prose in a lovely, interactive way.

Screenshot of the 'Grid' page of the playground book. The full text is at https://github.com/grey280/SwiftLife/blob/master/Swift%20Student%20Submission.playgroundbook/Contents/Chapters/Chapter1.playgroundchapter/Pages/Grid.playgroundpage/main.swift — Don’t worry, the real version (and some videos) are below.

Doing the actual writing was pretty fun. This is a concept I’ve spent a lot of time learning about, just because it captured my interest, and I wanted to share that in a fun way.

Overall, I’m quite happy with the result. If you’d like to see more, I’ve made recordings of the ‘randomized grid’ and ‘Wolfram rule’ pages running, and the actual playground is available on GitHub.