nui — shared node model for La Pavoiserie

The vocabulary a view tree is described with, and the two contracts a renderer consumes it through. Shared by the platform UI libraries — sui, aui, wui, cui, qui — and sitting above rui, which owns state and change propagation.

nui describes what a node is. It renders nothing.

Two modes, because one is not enough

A view tree is consumed in one of two ways, and which one is not a matter of taste — it is dictated by the host:

• Pull — the host diffs and re-renders on its own (SwiftUI, Jetpack Compose). The native renderer walks the tree on demand and asks for one thing at a time. Diffing on the Haxe side would duplicate work the framework already does. → NodeSource<Node>
• Push — the host diffs nothing (Qt/Silica, a terminal). It has to be told what changed, so Haxe holds the tree, compares it with the previous one, and applies targeted patches. → Node + PropValue + NodeSink<Native>

Both express the same vocabulary: type, children, key, typed properties, an ordered modifier chain, actions.

import nui.Node;
import nui.PropValue;

var view = new Node("VStack")
    .child(new Node("Text").prop("text", PString("Bonjour")))
    .child(new Node("Button", "add").prop("label", PString("Ajouter")));

Documentation: docs/ (docsify — docsify serve docs, or any static server).

Install

Usually transitive: a backend that has adopted the model declares it. Standalone:

haxelib git nui https://github.com/lapavoiserie/nui

Status

Young. The vocabulary and both contracts are defined and covered by test/Check.hx (29 checks, including a toy implementation of each contract to prove both are satisfiable):

haxe -cp src -cp test -main Check --interp     # rapide
haxe -cp src -cp test -main Check -cpp bin && ./bin/Check   # et sur cible compilée

Run both. --interp tolerates things a compiled target does not — notably switch on a null enum, which segfaults under hxcpp and is exactly how an absent property behaves.

Every backend has adopted it: cui, pui, sui, aui on the pull contract, qui and wui on push — the per-backend notes live in adopting. The model also has a third face now: the snapshot contract ships a tree as pure data across a process boundary, closures replaced by stable action ids — which is what a Companion surface projects and a widget snapshot will ship.

License

MIT.