utils/design_system

design_system

The shared Flutter component layer for kuhy's apps.

~/src/utils/unified-design-system/ froze the token layer — one palette, one spacing scale, one type scale — but it is documentation only: 1220 lines of prose and annotated HTML, zero importable code. Every repo transcribed the token table by hand, and then drifted from it.

This package is that same token set as Dart, plus the handful of widgets that had each been reimplemented in three or more repos. The components own the tokens: a consumer that depends on this package has nothing local left to edit, so the palette is enforced by the compiler and the package manager instead of by prose plus discipline.

Consuming it

Tag-pinned git dependency, matching the convention sync_settings_ui and crdt_sync_dart already use:

dependencies:
  design_system:
    git:
      url: https://github.com/kuhyx/utils
      ref: design_system-v0.1.0
      path: design_system

Then delete the repo's local lib/ui/theme.dart and import the package:

import 'package:design_system/design_system.dart';

MaterialApp(
  theme: buildLightTheme(),
  darkTheme: buildDarkTheme(),
  // ...
);

What's in it

Export	Replaces
AppPalette	~318 raw Color(0x…) literals, almost all inside hand-copied theme files
AppSpacing / AppRadius / AppTextSize	the six-repo consensus scales, transcribed per repo
buildLightTheme() / buildDarkTheme()	10 divergent theme.dart copies (2 byte-identical, 8 drifted)
AppStatusColors	4 hand-rolled ThemeExtensions with inconsistent field sets
confirmDestructive()	~35 inlined AlertDialogs
showToast() / showError()	~38 raw SnackBar sites and zero helpers
EmptyState	4 variants, only one of them reusable
SectionHeader	3 near-identical private widgets

Why the scales are what they are

The values are the six-repo consensus — todo, home_inventory, dufs-cloud, habit_stack, and untools all shipped byte-identical copies — which is also exactly what unified-design-system/DOCS-tokens.md specifies. Repos that had drifted (diet-guard, macro-cam) are corrected to this package, not the other way round.

Why explicit ColorSchemes, never fromSeed

The palette is hand-picked to hit specific contrast ratios. A seeded scheme silently replaces those values with algorithmically derived ones. The secondary/tertiary slots are set explicitly for the same reason: without them, widgets that reach for secondaryContainer (e.g. SegmentedButton's selected segment) fall back to stock Material teal — confirmed on-device.

Development

flutter analyze                                  # must be clean
dart format lib test
flutter test --coverage
scripts/check_coverage.sh coverage/lcov.info 100 # 100% line coverage, gated

Coverage is a gate, not a convention: this ships as a 100%-covered shared package by requirement. The gate runs on pre-push.