Arcan 0.7 – The All Tomato | Hacker News Reader

Arcan 0.7 – The All Tomato

arcan-fe.com

> In the last release post we hinted at how Xarcan can be used to keep your own window manager, letting Arcan act as a display driver — as well as a security, control and configuration plane that selectively merge in arcan native clients with options for how, or if, X clients gets to see inputs and clipboard action.

Alright, I'm probably sold. A couple of Wayland's greatest faults are that 1. they enthusiastically broke everything that X provided except for displaying windows on screen, and 2. after 16 years so far, they haven't actually provided replacements. So anything that lets us improve on the X server while keeping backwards compatibility is a huge leap forward; I just want to see if the compat is good enough for accessibility and automation tools[0] to work smoothly.

[0] This is 1 category, not 2.

If you read through the posts, Arcan is probably way ahead of Wayland with accessibility features. A LOT of thought has went into nearly every aspect of its architecture.

A slight nuance: Yes, I absolutely agree that Arcan is winning on a11y features overall; I'll go stronger and say that it doesn't just exceed Wayland, I think it's better than X was. What I meant specifically is that I want to see if it's backwards compatible with at least some of the tools I use on X, because it looks like (especially from this post) Arcan might be able to hand existing tools an X-compatible interface (doing actual access control and everything behind the scenes but that's all invisible to the tools using this interface) and let me keep using what I already have without having to (re)write anything new. As an example: On X, I can use `xdotool type --window $WINDOW_ID "sometext"` to type into a window even if it's not active. On Wayland, your best hope is that you happen to be using a compositor that's implemented some nonstandard API to do that. My hope is that Arcan implements enough of X that you can make it work, albeit probably with some explicit permission-granting.

Of course, Arcan looks good enough, and actually exposes enough API surface, that if it's not compatible with my existing tools then yes I probably will write whatever I need over its native APIs and just run with that. But it'd be nice if I didn't even need to do that:)

I see what your meaning now, thanks for making it clear. I haven't used Arcan in a while, but from what I remember from my (admittedly little) use and architecture reading, it might be in the best spot to get what you want. Lua bindings are pervasive and should in theory get close to what you want, but more research and work is needed to realise that.

But yes, I really feel bad that after 16(!) years, wayland is still a shitshow in all the cases of not drawing windows on the display, and I say this as someone who has been using Wayland daily for half a decade now, and lived through things being even shittier. I just silently keep wishing Arcan gets there as a universal drop-in replacement.

I can't find the link now, but there are two ways (I know of) for getting the xdotool way to work. One way is the Durden 'control' socket and a standalone tool 'arcan-cfgfs /path/to/.arcan/appl-out/durden/control /my/mountpoint' that is a FUSE driver. You can mount the desktop as a file system and automate everything like that: echo "typethis" > /my/mountpoint/windows/all/text/input". Another is to expose that more generally with hookscripts (force-injected Lua scripts that override or add features to the WM you use, arcan -Hhooks/something.lua).

from the about

"Arcan is a powerful development framework for creating virtually anything between user interfaces for specialised embedded applications all the way to full-blown standalone desktop environments. Boot splash screen? no problem. Custom Interface for your Home Automation Project? sure thing. Stream media processing? Of course."

Still dont really understand what this is?

It is a gui framework that allows you create terminals where you can detach any running process into another terminal.

Since it is a complete toolkit, you can have detachable applications where you send both code and state to a server and retrieve it from another device (like Apple's continuity).

In the end it is just a bunch of lua scripts talking to other components via /dev/shm and to other computers using a new protocol called a12://

I've been trying to understand it for a while now, it seems very cool.

Best short answer I have is that it's a lot of things working together. At it's core there's an IPC interface that's geared towards real time audio/video and an event loop that's scriptable in Lua that can read frames, process them, and then draw it to the screen.

This lets you do cool things like having parts of the frame drawn by another process, or on another computer seamlessly. And its more secure to punt things like codec processing on another thread anyways since those are common targets for exploits. Plus, the scripting ability makes it very easy to intercept streams and modify them as you please.

There's more to it, I recommend the blog, it has a fun sort of zen riddle tone that I personally like a lot. This article is my favorite: https://arcan-fe.com/2021/09/20/arcan-as-operating-system-de...

It is a windowing system, but one taking more inspiration from X than wayland. So it is all about remote programs and transferring displays from one device to another.

Personally, I find this area of study much more compelling than wayland.

I also love how on the one side, you have the X crowd(admittedly me) saying "look, we have worked on this thing for 30 years it works and has this massive accumulated feature set". And on the other you have the wayland crowd saying "yes that's the problem, we could do so much better by throwing all that out and starting over with a local compositing focused struct". And then, amid this huge fight, not bothering anyone, you have one person, who comes out of his cave every couple of months and goes, "look at this, I made a new windowing system from scratch that is designed around transferring windows from one device to another"

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