imp_trading_chart 0.2.0

A high-performance trading chart engine for Flutter with CustomPainter rendering, optimized for large datasets, real-time updates, and smooth pan & zoom.

Changelog

0.2.0

Added

• Added public ImpChartController for programmatic chart control without exposing internal engine types
• Added public controller snapshots and event APIs: ChartViewportSnapshot, ChartVisibleRange, ChartSelectionSnapshot, ChartRenderSnapshot, and ChartEvent
• Added public ChartFollowLatestState for explicit live-update UX observation
• Added initial package test foundation under test/unit, test/widget, and test/contract

Changed

• Updated ImpChart and all factory constructors to accept an optional controller while preserving existing usage
• Added snapshot-based observation hooks on ImpChart for viewport/state/event monitoring
• Extracted chart padding logic into a reusable PaddingResolver
• Formalized preserve-context live-update UX with auto-follow near the latest candles and no forced scroll while detached in history
• Refactored ChartPainter into a delegate-based rendering shell while preserving existing visual behavior and public usage
• Reduced ImpChart widget responsibility by extracting pulse, gesture-session, and live-update affordance helpers

Internal

• Introduced controller-side collaborators for state storage, command execution, live update handling, interaction state, and viewport policy
• Completed the internal migration toward a controller-centered architecture without breaking existing public widget calls
• Split rendering concerns into focused internal delegates for line, grid, axis labels, current price, ripple, and crosshair drawing

Fixed

• Restored auto-follow behavior for live data updates while preserving user context when the chart is detached from the latest candles
• Hardened widget-side candle change detection for apps that mutate the same candle list instance in place
• Added the missing tap-to-latest Live affordance when live data arrives during detached historical viewing

Tests

• Expanded controller and widget coverage for follow-latest thresholds, preserve-context updates, and in-place mutated list rebuilds

0.1.2

Added

• Created CONTRIBUTING.md with project guidelines and PR process
• Added CODE_OF_CONDUCT.md (Contributor Covenant)
• Added ARCHITECTURE.md explaining engine-first design and rendering pipeline
• Improved README with Contributing and Stability & Versioning sections

Documentation & Hygiene

• Marked internal classes in lib/src/ as internal implementation details
• Enhanced example app with helpful comments for future contributors
• No breaking changes - Behavior and public APIs remain fully stable

0.1.1

Fixed

• Resolved deprecated Matrix4 scaling API usage
• Fixed internal import issues and warnings
• Package description updated
• No public API changes

0.1.0

Initial release

• High-performance trading chart engine for Flutter
• CustomPainter-based candlestick rendering
• Viewport-driven drawing (only visible data rendered)
• Cached price scale and coordinate mapping
• Pan, zoom, and double-tap gesture support
• Fully customizable chart style and layout
• Engine-first architecture (Data → Engine → Rendering)