CLAUDE.md

1# CLAUDE.md
2 
3This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
4 
5## Project Overview
6 
7FL Chart is a highly customizable Flutter chart library supporting 6 chart types: Line, Bar, Pie, Scatter, Radar, and Candlestick. Single-package Flutter library (not a monorepo).
8 
9## Common Commands
10 
11```bash
12make sure              # Run tests + checkstyle (use before pushing)
13make runTests          # flutter test
14make analyze           # flutter analyze
15make checkFormat       # Verify formatting (dry run)
16make format            # Auto-format code
17make checkstyle        # analyze + format check
18make codeGen           # Generate mock files: dart run build_runner build --delete-conflicting-outputs
19flutter test test/chart/line_chart/line_chart_painter_test.dart  # Run a single test file
20```
21 
22## Architecture
23 
24### Per-Chart Pattern
25 
26Every chart type in `lib/src/chart/` follows a consistent structure:
27- `{type}_chart.dart` — Widget (extends `ImplicitlyAnimatedWidget` for built-in animations)
28- `{type}_chart_data.dart` — Data classes (extend `BaseChartData` or `AxisChartData`)
29- `{type}_chart_painter.dart` — Canvas drawing logic (extends `BaseChartPainter`)
30- `{type}_chart_renderer.dart` — Rendering widget that builds the custom painter
31- `{type}_chart_helper.dart` — Chart-specific utility functions
32 
33### Class Hierarchy
34 
35```
36BaseChartData
37├── AxisChartData (charts with X/Y axes)
38│   ├── LineChartData
39│   ├── BarChartData
40│   ├── ScatterChartData
41│   └── RadarChartData
42├── PieChartData
43└── CandlestickChartData
44```
45 
46Painters follow the same hierarchy: `BaseChartPainter` → `AxisChartPainter` → specific painters.
47 
48### Key Design Decisions
49 
50- **CanvasWrapper** (`lib/src/utils/canvas_wrapper.dart`): All drawing goes through this proxy instead of `Canvas` directly, enabling unit testing of paint logic with Mockito.
51- **PaintHolder**: Holds current data, target data, text scaler, and virtual rect — passed to painters for rendering and animation interpolation.
52- **Implicit animations**: Charts use `ImplicitlyAnimatedWidget` with `*DataTween` classes. Default: 150ms linear.
53- **Equatable**: All data classes use `equatable` for value equality.
54- **Lerp**: Data models must implement a `lerp()` method to enable smooth implicit animations between states. See `lib/src/utils/lerp.dart` for helpers.
55- **Theme-aware text styles**: When rendering text in painters, always use `Utils().getThemeAwareTextStyle(context, style)` instead of hardcoded fallback `TextStyle` values. This merges user-provided styles with the app's theme.
56 
57### Touch System
58 
59Each chart type defines `*TouchData` and uses `FlTouchEvent` base class. Touch callbacks are configured in the chart data classes.
60 
61## Testing
62 
63Tests mirror the `lib/` structure under `test/`. Each chart has tests for data, painter, renderer, and helper. Painter tests mock `CanvasWrapper` to verify drawing calls.
64 
65Key test utilities:
66- `test/helper_methods.dart` — Path/RRect equality helpers
67- `test/chart/data_pool.dart` — Shared mock data
68- `*.mocks.dart` files are generated by Mockito (run `make codeGen` to regenerate)
69 
70## Code Style
71 
72- Uses `very_good_analysis` linter (strict, with some relaxed rules in `analysis_options.yaml`)
73- `public_member_api_docs` is disabled — public API docs are not enforced
74- `lines_longer_than_80_chars` is disabled
75- Generated `*.mocks.dart` files are excluded from analysis
76 
77## PR Conventions
78 
79PR titles must follow Conventional Commits: `<type>: <Subject>` (e.g., `feat: Add tooltip support`). Types: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert. Breaking changes use `!` (e.g., `feat!: Change API`). Subject starts with a capital letter.
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