Me porting Runestone from UIKit to AppKit.

Yay! Runestone now works with... *Checks notes*... UIKit?? 🤨

In order to prepare for AppKit support, I had to rip the internals of Runestone apart and put it together again. For the first time in 36 hours, Runestone now works with UIKit again.

So I now have an NSWindow with an NSView that receives keystrokes. That's like step 0 in building a text editor, right?

There's such a long way to go still before Runestone is rewritten in AppKit. I hope I'll eventually turn a corner where all my work from UIKit can be reused and I ✨magically✨ have an AppKit implementation.

Runestone just rendered its first text using AppKit. Baby steps, y'all.

The AppKit version of Runestone now supports scrolling the content.

This involves a bit more than just wrapping everything in an NSScrollView because Runestone only renders the lines within the viewport.

Baby steps, y'all.

Time to add a caret that shows where characters will be inserted. I'm a little bummed that I have to implement this myself. We get that for free in UIKit.
Runestone for AppKit now has a caret. Baby steps, y'all.

I need to implement all moving within lines myself 😑

In the screenshot I'm logging the selectors that I don't handle but that AppKit expects me to handle. This is something we get (almost) for free in UIKit. Honestly, I really don't want to write this logic.

Got navigation with the arrow keys working in Runestone for AppKit.

I figured out how to reuse some of the code from the UIKit implementation so this turned out to be much easier than anticipated.

Next up is adding support for jumping between words with Option+Left/Right arrow keys.

Baby steps, y'all.

In order to move from word to word, UIKit relies on an implementation of UITextInputStringTokenizer. I managed to replicate UIKit's calls to my string tokenizer and reuse a lot of logic for moving between words. Baby steps, y'all.

While working on moving between words in Runestone for AppKit I found that the UIKit version had an incorrect behavior when moving between words followed by an emoji. The caret would always jump all the way to the end of the document which isn't correct, obviously. Fortunately, that was easy to fix and the fix works in both UIKit and AppKit.

And yes, it is supposed to jump all the way from the word "emoji" to the word "cool". That's how TextEdit does it too. Baby steps, y'all.

And now Runestone for AppKit supports moving to the line and document boundaries as well as clicking with the mouse to move to the closest location.

Maybe the next step is to support text selection. Or something more fun like line numbers.

Baby steps, y'all.

Fortunately, invisible characters, line height, kerning and theming works with no changes needed 😃

Line numbers and highlighting the selected line now works in Runestone for AppKit.

This one was a bit tricky because the view hierarchy is different between AppKit and UIKit and there's some important layering going on here to make it look the way I want it to.

On the other hand, disabling line wrapping worked without any changes 😃

Baby steps, y'all.

I quite like this look where the title bar is big and transparent ✨

Taking a break from this thread tonight*. I did a few minor things that aren’t worth showing off but I’ll prioritize playing with the Quest 2 and watching Slow Horses for the rest of the evening. I need a short break 🤗

* Since I’m posting this I guess I’m not really taking a break.

Just tested syntax highlighting in Runestone for AppKit for the first time. Was happy to discover that it just works 😃

Baby steps, y'all.

Mostly got text selection, copy, paste, and cut working in Runestone for AppKit today 😃

There are still a couple of bugs in the text selection that needs to be fixed but it's getting there.

Baby steps, y'all.

Still polishing the text selection in Runestone for AppKit. Getting all keyboard shortcuts working as expected is extremely tricky but I'm getting closer. However, I've just got text selection working with the mouse so that's something 😄

Baby steps, y'all.

In case you would like to start playing around with Runestone for AppKit, you can do so already now. It’s available in the GitHub repository: https://github.com/simonbs/Runestone/tree/mac

I’m still working on this, so bugs should be expected. Don’t waste too much time reporting issues. At this point I likely know they’re there but haven’t gotten around to fixing them yet 😊

And in case you are using Runestone in your project, remember that I have GitHub sponsors setup 🫶 https://github.com/sponsors/simonbs

GitHub - simonbs/Runestone at mac

📝 Performant plain text editor for iOS with syntax highlighting, line numbers, invisible characters and much more. - GitHub - simonbs/Runestone at mac

GitHub

@simonbs Replaced NSTextView with Runestone in my Proxygen app and it’s already super promising. Rendering works great, layout of text on window resizing is fast, and scrolling long text (that 800kB response) is buttery smooth on an M1 Mini.

You’ve done great work!

@pasi Wow! You’re fast! Thanks for testing 🙏

Please excuse the bugs. Hopefully I’ll get more squashed over the coming weeks 😊

@simonbs A minor hiccup in the beginning was Xcode not liking a different branch of the same Swift package in one project, even if they’re used in different targets (iOS and Mac app). Some error about the package already being imported.
@pasi Interesting. I haven’t tried that. I’m unsure if that’s an edge case for now that it doesn’t really make sense to address. I guess that whenever this goes to 1.0.0 or whatever then people will use the same branch on iOS and macOS.
@simonbs Yeah don’t worry about it all. So I guess on iOS TextView will refer to the UIKit class and on Mac the AppKit one?
@pasi Yep, that’s the plan. The plan is to make them as close to each other as possible but it’s not a strict requirement. And if everything goes well, I’ll wrap them in a SwiftUI type so they can be used in a multi-platform project.
@simonbs Okay I was an idiot. Of course building the mac branch for iOS target just works. I don’t know why I expected otherwise. This is excellent!