drafter

Releases

1. ▸▾0.3.028 Jun 2026

   feat: chart interactivity, robustness, full API docs, and DrafterLege…

   feat: chart interactivity, robustness, full API docs, and DrafterLege…

   Open source →

   Additional notes

   Added

   • Interactivity — a new InteractiveChart wrapper turns any chart into a touch/mouse-driven one: a trackball with a de-overlapping multi-series tooltip, tap value-selection, and drag range-selection, all painted on a non-rebuilding Canvas overlay so the base chart's reveal animation is never disturbed. Works across every chart type — cartesian charts (line/area/step/bar/candlestick/ stream) get a trackball-column tooltip + range band; radial and free-layout charts (pie/donut/polar/sunburst/treemap/heatmap/funnel/bullet/box-plot/bubble/ gantt/sankey/scatter/radar) get per-mark hover highlighting.
   • ChartInteraction config — independently toggle tooltip, selection and rangeSelection, with onSelected / onRangeSelected callbacks and a custom rowLabel tooltip formatter.
   • Public interaction model — ChartScene, PlotMark, ChartSelection, ChartRange (from package:drafter/drafter.dart) and the pure ChartHitTest / LabelLayout helpers (from package:drafter/painting.dart), so you can hit-test custom charts. Renderers opt in via the InteractiveRenderer interface and a buildScene(Size) derived from the same math they paint with.
   • CartesianScale — a reversible data↔pixel mapping shared by paint and hit-test, so the two can never drift.
   • Every chart widget (and InteractiveChart) now exposes a duration parameter to tune the entrance-animation length.
   • ChartRenderer / InteractiveRenderer are now re-exported from the main package:drafter/drafter.dart entrypoint (they appear in InteractiveChart's signature).
   • DrafterLegend — a reusable, theme-aware legend widget. Build it from explicit LegendItems or from a list of labels (DrafterLegend.fromLabels, which colors each entry by the active theme palette). Supports horizontal (wrapping) or vertical layout, square / circle / line markers, and an optional onItemTap callback for wiring series toggling.

   Fixed

   • Robustness — non-finite (NaN / Infinity) input values are now coerced at ingestion across all value-based charts, so malformed data can no longer produce a non-finite Canvas coordinate (a debug assert) or reach a toInt() (which threw UnsupportedError even in release builds — histogram binning, bubble axis rounding, line/bar axis steps).
   • InteractiveChart resets its interaction state when its renderer changes, so a stale selection highlight can't linger over new data, and it no longer writes to its disposed notifier if the pointer exits during teardown.

   Performance

   • The interaction overlay only repaints when the resolved hover/selection state actually changes (value-equal snapshots), is isolated in its own RepaintBoundary, and hit-tests by squared distance.
   • Layout-heavy renderers (heatmap, treemap, sankey, candlestick moving-averages) memoize their progress-independent layout per size instead of recomputing it on every animation frame; candlestick moving averages now use an O(n) sliding window.

   Documentation

   • The full public API is now documented (every constructor, field and getter), enforced by enabling public_member_api_docs in the analyzer.