MacKuba

< Previously on WatchKit Adventure…

This is the third part of my series about building a WatchKit app that shows current air pollution level on the watch face (it started here). In this episode, we’re going to build the app’s main UI. I will be building on top of some data handling & networking code written in the previous episode about complications, so if you haven’t seen that one, you might want to at least skim through it to get some idea about what this is about. Browse through the WatchKit category to see the whole list.

We’re venturing into a somewhat uncharted territory now… The WWDC talks about WatchKit are an amazing source of information and they’re great to get started (I definitely recommend watching them, especially the earlier ones, from 2015 & 2016), but once you actually start building things and run into a problem, there’s surprisingly little help available. Even StackOverflow isn’t of much use. There aren’t many books out there either that are up to date – I got one from raywenderlich.com, but it doesn’t really answer the hard questions, and it wasn’t updated since watchOS 4; Paul Hudson has another, and that’s pretty much it.

I’ve tried to figure out some things myself, but some questions are left unanswered. If you know how to solve anything better than I did, please let me know in the comments.

In the last few weeks I’ve been trying to catch up on SwiftUI - watching WWDC videos, reading tutorials. Not the new stuff that was announced 2 months ago though - but the things that people have been using for the past year.

Last June, like everyone else I immediately started playing with SwiftUI like a kid with a new box of Legos. In the first month I managed to build a sample Mac app for switching dark mode in apps. However, after that I got busy with some other things, and never really got back to SwiftUI until recently, so by the time the “version 2” was announced at the online-only WWDC, I’ve already forgotten most of it. So in order to not get this all mixed up, I decided to first remember everything about the existing version, before I look at the new stuff.

Back then, when I was watching all the videos and doing the tutorial, I was taking a lot of notes about all the components, modifiers and APIs you can use, every single detail I noticed on a slide. However, I was surprised to see how many of those things I wrote down don’t work anymore. After the first version that most people have played with and that the videos are based on, there were apparently a lot of changes in subsequent betas (especially in betas 3 to 5). Classes and modifiers changing names, initializers taking different parameters, some things redesigned completely.

I’m the kind of person who cares a lot about their digital privacy. It makes me very uncomfortable when I see ads on Facebook for something I opened on another site a moment ago, and I generally don’t like it when companies are learning more about me than they should, even if the effects of that tracking aren’t as obvious.

That’s why for example I’ve been trying to move away from Google services as much as possible (I use ProtonMail as my main email and Apple’s iWork for documents), I also started using Tresorit and iCloud1) for file sync instead of Dropbox. That’s also one of the reasons why I’ve always used some kind of ad & tracker blocker in my browsers – previously Ghostery, now I also use Brave and I’ve been experimenting with making my own ad blocker.

So it always makes me happy when Apple introduces another change to their OSes that limits the kinds of data that Mac and iOS apps can use without our permission. I especially liked:

• when iOS 11 introduced the “While Using” option for location access that was non-optional for apps
• the “Allow Once” option for location access in iOS 13
• permissions to things like camera, microphone or screen recording on the Mac

When I watch conference talks, I like to take notes - either on an iPhone or iPad when I’m in the conference room, or on the Mac when I’m watching online like in case of WWDC (I’ve never seen it in person). It makes it easier for me to remember the most important content from the presentation, and especially in case of WWDC notes I often come back to them to find some specific piece of information - WWDC talks are a very important part of documentation of how to use Apple’s APIs, sometimes (sadly) the only piece of documentation about the specific class or method that’s available.

I have a fairly large archive of those notes (around 20 from each year on average), usually just stored as one long note in the Notes.app, and I’ve been thinking for a while that it could make sense to somehow share them with the world. I have no idea how useful they will be for others, since I write them primarily for myself, they’re much more condensed than blog posts and basically written as just a “diff” from what I knew before, but I guess I won’t know until I try.

One problem I had with sharing the notes is that they’re written as completely plain text, something like this:

Since my update to the iOS version of Banner Hunter was rejected by app review, the app’s been in a kind of Schrödinger state, both dead and alive. It’s still selling those few copies a week, and I’m updating the blocklist, but I’m afraid to make any updates to the Mac app now… So since then I started looking for some other ideas for new apps I could build instead.

One thing I started working on is a Chrome version of Banner Hunter. I wasn’t really planning to do it before, but since Apple pushed me now… I might as well give it a try. I have no idea if it’s possible to make any money on Google Store, since the vast majority of extensions are free, but we’ll see. The main part of the app is done, but I need to work on the non-technical parts like graphics and copy, and it will probably have to wait until late summer at least.

I’ve got another idea though which has kind of come up by itself, which is… to build an ad blocker for Safari.

(TLDR: here’s the landing page.)

I’ve been tracking the growth of the new coronavirus ever since it first appeared in China in the last week of January, and even more since it spread to Europe around mid February. Initially I’ve been looking mostly at the popular ArcGIS dashboard made by Johns Hopkins University that everyone is probably familiar with.

However, I really wanted to see some charts showing how the numbers grow in each country separately, since just seeing “8000 in Italy” doesn’t tell me much if I don’t remember how much it was yesterday. At that point it wasn’t possible to see that kind of information on the dashboard, and I couldn’t find any other source that showed that in an accessible way.

But then I saw a mention in the footer on the dashboard that the authors have shared all their data (including past numbers) in a GitHub repository in the form of CSV files. So of course I decided to do what always comes to my mind when I have a problem to solve… build a new project :)

And that’s how the Coronavirus charts site was born.

I was going through some saved links and open tabs from June recently while finishing the WWDC collection post. I found a lot of interesting quotes about SwiftUI, Catalyst and the future of Apple platform development, and I decided to steal the idea from @mjtsai and put them together in one place. It might be interesting to look at this 5 or 10 years from now…

As I’m writing these words, it’s the last day of November and the temperature has just dropped to close to 0°C here in Poland. But let’s move back to a better time for a moment, to the first days of June - the long days of warm sunny weather, inviting you to spend some time outside… and the huge pile of new stuff that Apple had just dropped on us on the WWDC keynote day, inviting you to try to frantically read and watch everything at once, and don’t leave the computer until you’ve read it all.

For the past 4 years I’ve been trying to cope with this crazy period by collecting notes from the WWDC talks, release notes, saving tweets, links to blog posts and so on, and organizing it all in a single ordered blog post. Writing things down this way is how I learn best, it helps me put together all loose pieces of information into a single picture, and gives me the peace of mind that I haven’t missed or forgotten anything important.

I usually finish this by July, but this year was different - first I got really hooked on SwiftUI and spent some time doing some experiments with it, and then I was busy working on and releasing my iOS content blocker app and doing some travelling. It didn’t help that the sheer amount of new APIs added this year was simply overwhelming.

So I finally got back to this in November, and I’m posting the list here on the half-anniversary of the 2019 keynote (yes, it’s really been 6 months already!) - hopefully it will still be of use to you.