Constraint System

Maintain the UIKitPlus Constraint System

Use this LOCAL contributor skill when changing UIKitPlus constraint implementation or built-in constraint DSL behavior.

Load the smallest decision-complete context

1. Start from UIKitPlus AGENTS.md and SKILL_INDEX.md.
2. Use LAYOUT_SYSTEM.md as the primary architecture owner.
3. Add only the supporting contract needed by the change:
   • RUNTIME_MODEL.md for deferred activation/lifecycle;
   • STATE_SYSTEM.md for State-backed constants;
   • MUTATION_MODEL.md for re-entrant/update flows;
   • FLUENT_CHAIN_CONTRACT.md for public fluent API changes.
4. Use SOURCE_MAP.md before broad source discovery.

Do not bulk-load every supporting owner merely because constraints can touch them.

Plan checklist

• Classify the affected channel: solo, super, relative, or mixed.
• Identify the current activation owner and whether movedToSuperview/deferred activation is involved.
• Check relative/tag resolution and AddedViewWithTag retry behavior when applicable.
• Check State listener/link ownership when constants are reactive.
• Record public fluent/State-surface effects before mutation.

Implementation rules

• Keep pre-constraint queue ownership explicit (notApplied* / applied*).
• Preserve existing activation helpers when deferred behavior is required.
• Keep replacement/deactivation semantics explicit; do not leave duplicate active constraints hidden behind convenience APIs.
• Preserve explicit listener ownership for State-backed constants.
• Do not introduce a second layout/activation engine to compensate for a local edge case.

Audit

Verify the final source/diff against the selected architecture owners and prove:

• no hidden constraint duplication or orphaned deactivation path;
• relative/tag constraints retain retry and eventual activation behavior;
• immediate and deferred activation remain consistent;
• State propagation follows the current State contract when in scope;
• fluent Self semantics remain intact for changed public APIs;
• unrelated source and governance are untouched.

Stop and re-plan if the change requires a new layout lifecycle/ownership mechanism rather than an implementation inside the existing constraint architecture.