taffy-java — CrystalGraphics fork

A fork of vfyjxf/taffy-java, a pure-Java port of Rust Taffy (Flexbox, Grid and Block layout).

This is the layout engine behind CrystalGUI, carried here as a fork rather than consumed as a Maven artifact so that defects in it can be fixed. MIT, like upstream — see LICENSE, which is upstream's own notice, unchanged.

MODIFICATIONS.md is the list of what differs from upstream, and the statement of changes MIT requires. Read it before touching anything here.

The vendored baseline is the published sources of dev.vfyjxf:taffy:1.1.4, unmodified except for what MODIFICATIONS.md records. Today that is one change: the deletion of a branch in FlexboxComputer.determineHypotheticalCrossSize that measured a flex item's cross size against its container's main size rather than its own, whenever the container had flex-wrap: wrap.

Two separate things broke, and neither announces itself:

• a leaf with a MeasureFunc reported a height for a width it was never given — its width stayed correct, so the symptom is clipped text rather than a box that looks wrong;
• an item with an aspect-ratio — the case the branch was written for — collapsed to zero height.

TaffyWrapMeasureTest covers both, plus the counter-assertion that wrapping still wraps.

This repository does not build on its own, by design. It carries a build.gradle.kts and no settings file or wrapper: it is a git submodule of CrystalGUI, included from that project's settings.gradle.kts as :taffy, exactly as gl-debug-harness is. So:

git clone --recursive https://github.com/CrystalGraphics/CrystalGUI
cd CrystalGUI
./gradlew :taffy:test        # this module's regression tests

Upstream's own build, tests and gentest tooling are deliberately not carried here — that tooling generates a conformance suite against Rust Taffy's fixtures, which is upstream's job and not something a consumer fork should be re-running. What this fork tests is what this fork changed.

Keep changes minimal and annotate them in place with a // CrystalGUI: comment. Do not reformat these files — a whitespace pass makes the next diff against upstream unreadable, which is the whole reason a vendored dependency is worth less than a pinned one.