UI Android

ui-android — Slop-Free Compose UI Skill

You are generating production-grade Android UI in Jetpack Compose + Material 3 + Kotlin 2.0+. This skill exists because untouched LLMs produce AI slop: purple→pink Brush.linearGradient, hardcoded 16.dp everywhere, three-card LazyVerticalGrid "features" sections, "Beautiful and intuitive" copy, decorative rememberInfiniteTransition shimmers, Color(0xFF...) literals scattered through composables, and the median of every Compose tutorial scraped from GitHub. This skill replaces guesses with constraints.

The non-negotiable rule: NEVER use a buzzword in place of a token. Words like clean, modern, professional, sleek, premium are banned from your reasoning. Every aesthetic choice must trace back to a named anchor recipe in anchors.md and a token in Theme/Color.kt, Theme/Type.kt, Theme/Spacing.kt, Theme/Shape.kt.

This skill targets Material 3 Expressive on Android 14+ (API 34+) with Compose BOM 2026.x. Strict on Material mechanics: 48dp touch targets, edge-to-edge insets, predictive back, dynamic color opt-in, Material Symbols only. Brand has freedom over seed color, type personality (with Roboto Flex fallback declared), motion personality, shape family.

Workflow (follow in order)

Step 0 — Project scan (decides bootstrap vs extend mode)

Before any other action, check for:

DESIGN_RULES.md                                        # at repo root → if exists, you are in EXTEND mode
app/src/main/java/**/ui/theme/Theme.kt                 # Compose MaterialTheme wrapper
app/src/main/java/**/ui/theme/Color.kt                 # ColorScheme defs
app/src/main/java/**/ui/theme/Type.kt                  # Typography
app/src/main/java/**/ui/theme/Shape.kt                 # Shapes
app/src/main/java/**/ui/theme/Spacing.kt               # Custom spacing CompositionLocal
app/build.gradle.kts                                   # confirm BOM + material3 version
config/detekt/detekt.yml                               # detekt config

• If DESIGN_RULES.md exists: read it. Read existing theme files. Skip to Step 3 (Phase 2: UI). Use only existing tokens. NEVER add new colors/spacing/radii without asking.
• If theme files exist but no DESIGN_RULES.md: read the theme, infer the closest matching anchor, ask the user to confirm the inferred anchor, then write DESIGN_RULES.md and proceed to Phase 2.
• If neither exists: you are in bootstrap mode. Continue to Step 1.

Step 1 — Intake (interactive, bootstrap only)

Use AskUserQuestion to gather, in this order:

1. Anchor pick — show the 8 recipes from anchors.md (one-line summary each). Let the user pick 1–3. If 2–3, ask which is primary and which contributes type vs color vs motion. Note: Material You is the most native to Android — recommend it as the default unless the user has reason to deviate. Apple Music is allowed but call out it is Apple-leaning and will fight platform conventions.
2. Ban menu — show the 8 ban patterns from ban-patterns.md with the 3 default-on items pre-checked. Confirm.
3. Project context:
   • Content density: airy / balanced / dense
   • Primary surface: phone app / tablet / foldable / Wear (Wear has its own rules — bail and ask)
   • Dark theme: required (M3 default) / optional / none
   • Dynamic color (wallpaper-derived): on / off
   • Brand seed color (hex) — required if dynamic color is off
   • Min SDK (must be ≥ 34 for this skill; warn if lower)

Do NOT ask vibe questions ("how should it feel?"). Ask only the questions above.

Step 2 — Phase 1: theme tokens (gated)

Generate, in this order:

1. ui/theme/Color.kt — lightColorScheme(...) and darkColorScheme(...) derived from the chosen anchor + brand seed. Use the template at templates/Color.kt.tmpl. All Material 3 roles populated: primary, onPrimary, primaryContainer, onPrimaryContainer, secondary, tertiary, surface, surfaceVariant, onSurface, outline, error, etc.
2. ui/theme/Type.kt — Typography(...) mapped to Material 3 type scale (display/headline/title/body/label × Large/Medium/Small). FontFamily declared explicitly per anchor; default fallback is Roboto Flex variable font. Template at templates/Type.kt.tmpl.
3. ui/theme/Shape.kt — Shapes(...) with extraSmall, small, medium, large, extraLarge RoundedCornerShape per anchor.
4. ui/theme/Spacing.kt — custom Spacing data class + LocalSpacing CompositionLocal. Template at templates/Spacing.kt.tmpl. Exposed via MaterialTheme extension: MaterialTheme.spacing.md.
5. ui/theme/Theme.kt — AppTheme { content } composable wiring ColorScheme + Typography + Shapes + LocalSpacing. Honors isSystemInDarkTheme() and dynamic color opt-in (dynamicLightColorScheme(LocalContext.current)).
6. config/detekt/detekt.yml — slop-blocking detekt rules from templates/detekt-design.yml.tmpl. Add a detektDesign Gradle task wired into check.
7. DESIGN_RULES.md at repo root — fill templates/DESIGN_RULES.md.tmpl with chosen anchors, active bans, theme file paths, and verification command.
8. CLAUDE.md patch — append (do not overwrite): Before any UI/UX work, read and follow DESIGN_RULES.md.

Then run the Token Audit from verification.md and print the PASS/FAIL table to the user. Do not proceed to Phase 2 until the user approves.

Step 3 — Phase 2: UI

Generate the requested screen/composable using only tokens from the theme. Follow:

• component-anatomy.md — exact rules for Button, TextField, Card, ListItem, TopAppBar, NavigationBar, FAB, ModalBottomSheet, AlertDialog, Snackbar, empty/loading/error states.
• motion.md — Material 3 motion tokens (durations + easings), AnimatedVisibility, AnimatedContent, predictive back rules.
• copy-voice.md — every string is real, contextual copy. Sentence case for buttons (Material 3 default — never Title Case). No lorem ipsum. No filler.
• icons-imagery.md — Material Symbols family pinned per project. Coil + AsyncImage for images. No stock people.

Then run the UI Audit from verification.md AND ./gradlew detekt lint. Print the audit table. Fix every FAIL before claiming done.

Files in this skill

Hard rules (the model must obey these always)

1. No arbitrary values. Forbidden: Modifier.padding(13.dp), Modifier.size(372.dp), RoundedCornerShape(7.dp), Color(0xFF3A4F6B) inside a composable. Every dp must come from MaterialTheme.spacing or MaterialTheme.shapes. Every color must come from MaterialTheme.colorScheme. If a value doesn't exist, ask the user to extend the theme.
2. No buzzwords in code or comments. Banned strings in your output: clean, modern, professional, sleek, premium, beautiful, elegant (except in copy if the user explicitly asked for those words).
3. No default-style-tells unless the chosen anchor explicitly allows them. Specifically: no purple→pink Brush.linearGradient, no indigo→purple, no .blur() overlays on cards (only on bottom-sheet scrims if anchor specifies), no FontFamily("Inter") unless declared in Type.kt.
4. No filler copy. No lorem ipsum. No "Lightning fast", "Built for the modern web", "Powered by AI", "Get started in seconds", "The future of X", "Beautiful and intuitive".
5. Touch targets ≥ 48dp. Material 3 minimum. Use Modifier.minimumInteractiveComponentSize() or component sizing.
6. Edge-to-edge always on. enableEdgeToEdge() in the Activity, WindowInsets.systemBars / .safeDrawing / .imePadding respected. NO hardcoded statusBarsPadding() ignoring window insets API.
7. Predictive back gesture supported. Use BackHandler with predictive APIs where appropriate; sheets and dialogs honor it.
8. Every async surface has empty + loading + error states. No exceptions.
9. Dark theme parity. isSystemInDarkTheme() honored; both lightColorScheme and darkColorScheme populated with WCAG-AA contrast.
10. TalkBack labels on every icon-only IconButton via contentDescription. Decorative-only icons: contentDescription = null and parent has its own label.
11. You must run the verification checklist before responding "done". Print the audit table to the user.

What this skill is NOT

• Not a magic-aesthetic generator. You still have to pick an anchor and follow it.
• Not a copy generator. Phase 2 stops and asks for real copy when needed.
• Not a brand-design tool. Brand identity (logo, custom typography family selection beyond what anchors provide) is the user's call.
• Not a Wear OS / Android Auto / TV skill. Phone, tablet, foldable only.
• Not a replacement for design review with humans. The audit table is a floor, not a ceiling.