alt Hacker NewsThe problem with a constraint system is that it would likely be even more subject to performance problems than the current setup.
IMO what CSS layout really needs is:
1. A "proportion of available space" unit. That is, something like the fr unit in CSS grid except applicable to the width/height properties so it can be used in all layout modes and without an implying content-based minimum size (like fr does).
2. A new "display: stack" (name provisional) layout mode that simply stacks boxes one after the other like "display: block" but that works in both axes, and doesn't have quirks of block layout (margin-collapsing, floats, inline-block splitting, etc).
When combining 1 and 2 you'd have a much more intutive layout system that would still give you most of the power of Flexbox and could be implemented with much better performance.
(and you'd still be able to use the existing layout modes if/when you needed to extra power)
Replies
(1) could be answered with container query units. Set `container-type: inline-size;` on the parent element (falls back to the whole viewport if unset), then use, e.g., `width: 50cqw; height: 50cqh` in children. The value is a percentage of the given axis
What CSS needs (opinion, caveat, really far away in advanced features) is:
- A way to get values from sliders (type="range") (and style and modify them easily). Really, a way to get "value" from any <input> element.
- A way to have radio / checkboxes or labels inside labels work for multiple choices (or something other than making enormous arrays of radio selections and CSS choices)
- A way to have indexed arrays of numbers / choices (other than using a crazy complicated animation timing trick)
- String concatenation thats not so incredibly finicky and difficult to implement correctly
- Some way to retain the final "state" of a condition without resorting to playing an animation on "forwards" mode. Also, related, some way to not require the hidden checkbox hack everywhere.
- (Advanced, lower priority) A way to force var() calculation and optimizations other than making a zillion @property statements. "This expensive trig calculation is used a hundred times later on, better make it a separate ... nvm, it gets regex placed into every other calculation on the entire page ... " ¯\_(-_')_/¯
- If() and Function() ... wait, /inappropriate_swear, we're actually getting these after a quarter century.