overture VS Lunar

Fastmail shows lists of messages using a progressively-loaded list, where each item is of a consistent height (88px for me, but it can be a few other values too, depending on your configuration—I think 51px is the default). This means that the scrollbar is real and accurate, and you can seek to any point in your mailbox easily (provided your platform allows interacting with the scrollbar, which largely means “on desktop platforms”). But this does cause problems for very large mailboxes, because browsers only support finite lengths.

A few years back, while I worked at Fastmail, we had a ticket come in from an IE user that they could suddenly only access the first few messages in their mailbox. Trouble was they’d gone over IE’s limit, and IE just ignored the entire height declaration in that case, and so you ended up with only the initially-rendered list items available.

The limits I found:

• Firefox: ignores declarations that resolve to a value higher than 17,895,697 pixels (which is a bit more than 2²⁴).

• IE: ignores declarations that resolve to a value equal to or higher than 10,737,418.23 pixels (2³⁰ − 1 hundredth pixels).

• WebKit: clamps values somewhere around 2²⁵ (~33,554,432) pixels; clamping means you don’t need to worry about it so much, since that was the best workaround in other browsers anyway.

And so we ended up with the workaround code at https://github.com/fastmail/overture/blob/41cdf36f3e7c8f0dd1... (the Firefox check was of much older vintage, I just added the IE case). (Nowadays, the IE part is gone again because IE is gone, hooray!)

So yeah, it actually only took about 200,000 messages in the list to hit this limit and fall over, or subsequently just make the bottom of the mailbox inaccessible. 200,000 messages in one mailbox is uncommon, but not at all unrealistic, especially in an “All mail” sort of mailbox.

One uncommon place where clipping is justified at the design level: lazy-loading but finite lists. I’ll use Fastmail’s webmail (on which I worked a few years back) as an example. I could load a list of a hundred thousand emails, and each message in the list is 88px tall (containing four lines of text—approximately, sender and date, subject, and two lines of preview, with truncation on each), so the list container is made to be 8,800,000 pixels high¹, and I can use its scrollbar to immediately jump to any place, and it will figure out which messages to fetch and render based on the scroll position. If the subject line were wrapped, which would be nice at times, you’d lose this ability: you’d have to guess the approximate height of each element, and your scroll positions will be imprecise and you’ll have to make messy adjustments from time to time. Overall it generally won’t be too bad so long as there’s not too much variation in them, but it’s definitely still inferior.

¹ Browser do have limits on how large you can make containers, and handle excess in different ways. IE had the lowest threshold of failure at around ten million pixels, beyond which point it would ignore values; the workaround I implemented in https://github.com/fastmail/overture/commit/8d01c74d8c5d4ae0... came as a direct result of a customer reporting that scrolling was broken in IE in their mailbox with a couple of hundred thousand emails. Firefox breaks a little after 2²⁴ pixels, also ignoring values, so it’s still covered in https://github.com/fastmail/overture/blob/0c9828a5b77ad14383... (note the IE stuff is gone because IE is dead! :-) ). Chrome accepts larger values, but clamps them to about 2²⁵ pixels.

It is, however, interesting to note that Fastmail’s webmail doesn’t use EventSource, but instead implements it atop fetch or XMLHttpRequest. An implementation atop XMLHttpRequest was required in the past because of IE, but it still deliberately doesn’t use EventSource; my foggy recollection from a few years ago is that it had to do with control over timeout/disconnect/reconnect, and handling Last-Event-ID, plus maybe skipping browser bugs in some older (now positively ancient and definitely unsupported) browsers. The source for that stuff is the three *EventSource.js files in https://github.com/fastmail/overture/tree/master/source/io.

It’s done in a similar way on macOS: a dylib is added to the bundle and an LC_LOAD command is added to the app binary. The dylib is the first thing that runs because of using the constructor attribute, like this: https://notes.alinpanaitiu.com/Injecting%20a%20DYLIB%20into%...

The nice thing is that a signed app will refuse to load a dylib that does not have the same signature. So crackers will be forced to change the whole app signature which can be easily detected in app code.

I have that kind of protection in Lunar (https://lunar.fyi/) and Clop (https://lowtechguys.com/clop) and it seems to be good enough as they have no recent cracks.

Pretty sure Lunar [0] can do this for you, and you can buy a lifetime license.

[0]: https://lunar.fyi/

I've had good luck with the Lunar app - it manages my Dell and LG monitors on an M2. (No affiliation) https://lunar.fyi

Wild! I am working on exactly the same thing now for Lunar (https://lunar.fyi), and I'm also calling it Night Mode ^_^ what a coincidence

I've been trying to make "white regions in dark backgrounds" less painful for months, but doing that at the system level on macOS is incredibly hard. I see you're doing it with CSS filters, which make sense in the limited scope of an article. But applying something like that on the whole macOS UI would cause confusion.

I already use something similar on the iPhone: I read on the Kindle app which has white text on black background, then I have a full red Color Tint filter on the Triple Back Tap shortcut which I use before reading. Very similar effect to your solution, although I don't have images in my books.

I was comparing anti-piracy measures with DRM, I don't have actual DRM in my app. I can't block users that really bought the app from using it (which is what DRM is notorious for).

But I do have a license verification for the Pro features (https://lunar.fyi/#pro), and that is what people are cracking in the app. I only added more protection around this verification.

Lunar

There's no Reduce White Point on Mac as far as I am aware. However, you can use the fantastic Lunar [0] app to achieve this, as it supports "Sub-Zero Dimming".

To use it, I think you just need to start Lunar, and then press the Reduce Brightness button on your keyboard until it goes below the minimum Mac allows.

[0] https://lunar.fyi

As the dev of a macOS app that breaks all the time because of external hardware, the tone of the article hits close to home. (I’m talking about https://lunar.fyi/ whose brightness control commands can be blocked by USB-C hubs, “smart” monitors, too long cables etc.)

I had to disable public GitHub issues on the app repo [1] because people seemed to fuel each other with spiteful comments and “why can’t you just!!” sentences.

The contact form still attracts many such “entitled” people and it hurts to wake up to such messages, but at least I can choose to ignore those if I can’t bring anything to the discussion. There’s no peer pressure.

These people are expecting too much from a handful of developers who are sharing a lot of free work and time that could have been spent better than hunting new IDs in URLs and updating regular expressions.

[1] https://github.com/alin23/Lunar

Last year I bought a second computer for my music studio. I wanted to use the same set of 2 monitors and wired keyboard + trackpad on both machines.

I wrote simple scripts to switch my monitor inputs with keyboard shortcuts (even simpler with Lunar, amazing new Mac app — https://lunar.fyi), which saved me from having to press annoying input-source buttons.

But I couldn't for the life of me find a simple, suitable software controllable KVM switch. That still requires the hardware button to be controlled, so frustrating.

Some people like the process of writing code, more than the end result. I had a few months of that feeling, but nowadays it’s rarely about writing for me.

Just the other day I used Copilot to explain the disassembly of macOS KeyboardBacklight code, so that I can turn off the keyboard lights when using Lunar’s Blackout (https://lunar.fyi/#blackout)

It even helped me generate the ObjC function signatures from assembly and use the right calling convention in Swift afterwards. It really feels like magic.

I would have no joy in writing that code, it’s mostly bridging and translation anyway. I just need it to do this thing so that people can take advantage of it.