Macos Ulist

Maintain macOS UList / NSTableView

Use this LOCAL contributor skill for UIKitPlus's built-in macOS UList implementation.

Architecture authority remains MACOS_ULIST_NSTABLEVIEW.md (UL1–UL10). Load MACOS_ULIST_TEXTKIT2.md (UTK1–UTK8) only when TextKit 2 application rows are involved.

Load

1. Start from UIKitPlus AGENTS.md, SKILL_INDEX.md, and LAYER_MODEL.md.
2. Load MACOS_ULIST_NSTABLEVIEW.md as the primary domain owner.
3. Choose one final supporting architecture document only when needed:
   • TextKit 2 row: MACOS_ULIST_TEXTKIT2.md;
   • lifecycle/reuse/diffs: RUNTIME_MODEL.md;
   • constraints/height propagation: LAYOUT_SYSTEM.md;
   • update callbacks: MUTATION_MODEL.md.
4. Use SOURCE_MAP.md before broad source discovery.

Do not exceed the normal architecture budget without explicit escalation.

Before editing

• classify the real owner: generic UList, AppKit, or application row [UL1][UL7];
• verify native table width propagation and automatic-height ownership [UL1][UL2];
• verify the row is complete before first display [UL4];
• verify recycling is not performing measurement [UL5];
• verify width changes are not rebuilding the whole list [UL6].

Do not modify generic _UListCell merely because one consuming application's content system renders badly. For TextKit 2 rows, keep measurement/reflow in the application row and follow UTK1–UTK8.

Guardrails

Preserve one native table column, one current root per cell, four edge constraints, automatic heights, native scrolling, and targeted UForEach mutations [UL1][UL2][UL3][UL9].

Reject speculative scrolling opt-outs, forced layout during reuse, dual-root hosting, measurement caches/polling, generic content measurement, and width-driven full-list rebuilds unless the architecture is separately re-opened and approved.

Validation

Run the focused/full validation required by the current source task. When UL10 applies, rendered recycling and continuous live resize must both pass; success in only one mode is insufficient. TextKit 2 application-row work also requires the UTK8 rendered gate.

For ambiguous rendered geometry, use the current repository's visual-diagnostics route as a separate verification procedure; do not turn visual instrumentation into UList production behavior.

Audit

Report with applicable UL* and UTK* tags:

• final framework/AppKit/application ownership boundary;
• native width/height ownership preserved;
• no scroll/recycling measurement;
• continuous live resize without full rebuild;
• targeted/nonanimated height invalidation when applicable;
• targeted diffs/listener ownership preserved;
• rendered acceptance result;
• synchronized durable docs only where ownership facts changed;
• clean task scope.

Stop when a public API or generic framework change is required without explicit approval, or when evidence localizes the defect to one consuming application's content system.