7 comments

  • nicoburns 3 hours ago
    I maintain Taffy: AMA.

    I am currently in the process of building a wider browser engine / GUI toolkit on top of it (https://github.com/dioxuslabs/blitz). As part of that I am implementing a lot of the messier parts of CSS layout (floats, etc), and also grinding on fixing all the WPT tests which we track here: https://blitz.is/status/wpt/css/css-flexbox.

    The vision is a complete standalone implementation of the web layout algorithms that can be easily embedded (with individual algorithms enabled/disabled on a pay what you use basis), and which can also be part of a modular ecosystem of browser engine components that make it easier for people to create new browser engines.

    Beyond Blitz, some notable users are:

    - Servo which uses it only for CSS Grid

    - Zed which uses it via it's GPUI toolkit.

    • eviks 17 minutes ago
      I guess you've reviewed a few layout systems, do you have a strong view re. which one is the platonic best, i.e. we can ignore the practical considerations of matching CSS just because it's very popular
      • nicoburns 2 minutes ago
        The one from PanGUI (https://pangui.io/blog/05-layout-rework-and-benchmarks/) looks impressive. It seems to combine a lot of the power/flexibility from CSS with the performance of simpler systems. It's not open source though, so it's hard to evaluate properly.

        One thing I would love to see is CSS gain new unit which represents "a proportion of free space" (after fixed-size things have been sized) similar to fr units from CSS Grid but usable for properties like width/height and that would disable the "automatic minimum/content based size" that causes so many of the performance pitfalls with CSS layout.

        I think this could make CSS layout both faster and more intuitive for 90% of layouts. And you could retain the existing properties for advanced layouts and backwards compatibility.

        Flutter's blog post "constraints go down, sizes go up" [0] is the classic that I would recommend to anyone trying to understand UI layout. It doesn't cover every possible approach, but it applies to most of them including CSS. If you combine with a rule of thumb for keeping layout fast: "content-based sizing XOR flexible sizing" then you're well on your way to making a good layout system.

        [0]: https://medium.com/flutter-community/flutter-the-advanced-la...

    • actsasbuffoon 2 hours ago
      I used this for an internal project I can’t talk about, but it was a lifesaver. It allowed me to drop a really powerful layout system into a project that wasn’t doing traditional UI at all.

      The results have been fantastic. Thank you for this awesome library. I love it.

    • kkukshtel 3 hours ago
      Thanks for all this! I used Blitz a while ago for a product research spike around composing HTML to be rendered directly in a terminal with kitty or iterm's image protocol:

      https://www.npmjs.com/package/kittyhtml

      https://github.com/kkukshtel/kittyhtml

    • mrec 2 hours ago
      I think Bevy uses it too, right?
    • timw4mail 2 hours ago
      Floats? A fan of pain, are we?
      • nicoburns 1 hour ago
        Unfortunately 73% of websites use floats, so if you want to render the web then you have to support them!
    • fschuett 3 hours ago
      I used it in https://fschutt.github.io/printpdf for the HTML-to-PDF layout, just as a note. It is very useful, thanks for your work. Good luck on Blitz.
  • chrisweekly 3 hours ago
    Closely-related tangent: for an amazing resource showing how to leverage CSS from first principles, see https://every-layout.dev
  • jdnier 1 hour ago
    There are Python bindings via the stretchable library.

    https://github.com/mortencombat/stretchable

  • hereonout2 4 hours ago
    An unfortunate name for certain audiences in the UK!
  • LoganDark 4 hours ago
    I would be interested in something like Apple's constraint layout system. Nested flexboxes and grids can do a lot, but I kinda fell in love after seeing constraint layout. Even how window resizing is represented as a constraint with a certain priority too!
    • fschuett 3 hours ago
      https://github.com/dylanede/cassowary-rs but it's not that great on performance once you have like 1000+ constraints (used that library last in 2018 / 2019? maybe it has improved). I think https://github.com/christolliday/limn used it way back then.
      • nicoburns 3 hours ago
        Ratatui (TUI) uses cassowary layout with a faster underlying library.
    • nxc18 3 hours ago
      Came here to say the same thing. I feel like I’ve done my homework on CSS grid and CSS flex but no matter how much I use it, it will likely never become intuitive. Autolayout was love at first sight, and continued being a joy to use as long as I had the privilege of using it.

      I know the CSS people were painted into a box by legacy, but the design of both grid and flex honestly seem like the products of uniquely deranged minds. Unfathomable. Something like WPF’s grid is just as powerful as CSS grid but it doesn’t give you a mental disorder trying to understand it.

      • LoganDark 3 hours ago
        CSS grid and flexbox are very intuitive to me now, because I fell in love with them too before meeting constraint layout. But that may be because I was still young-ish when learning them. These days, it's starting to get harder for me to pick up new things...
    • scoopr 3 hours ago
      I believe there are several crates (and other languages too) inspired by the original cassowary paper, don't know how mature they are though.
  • troupo 4 hours ago
    My opinion is that no one should re-implement CSS layout orimitives and algorithms. Those are rather unique in how (by necessity and quirks if history) awkward, stange and bolted on they are.

    Explore other layout ideas. E.g. https://stackoverflow.com/questions/53911631/gui-layout-algo...

    • iainmerrick 3 hours ago
      Well, hang on, there are several different layout algorithms in CSS, right? They keep the old ones for backwards compatibility, and they have to interoperate which makes things more complicated; but flexbox and grid are relatively new and quite nice.
      • Rohansi 1 hour ago
        The people saying CSS is unfit for UI have probably never actually built a good UI in anything, and also realistically don't even know how to use CSS.

        Flexbox on its own is a simple and very capable algorithm that you can use anywhere. You can do a lot with flexbox alone (see Yoga: www.yogalayout.dev) so it's a great place to start. Taffy supports a few more layouts (block, grid) which have their own separate use cases but flexbox is enough for most things.

    • est 3 hours ago
      I side with your opinion. CSS is bad for UI layout (maybe good enough for text-flows idk)

      ... opens the SO link

      yeah there's no answer to it (even if someone does, it would likely be closed by 5 others)

  • righthand 4 hours ago
    <strike>This project IMO should admit it's taken a lot of it's inspiration from Clay, a C layout immediate mode UI library: https://github.com/nicbarker/clay/</strike>

    EDIT: Was wrong, see reply to this comment, need my coffee...still not a good excuse