ohlcv_chart 3.2.0

Candlestick charts for Flutter: 31 indicators, 29 drawing tools and 55 more chart types. Pure CustomPainter, no WebView.

ohlcv_chart

Candlestick charts for Flutter, with indicators, drawing tools and a library of other chart types. Pure CustomPainter — no WebView, no JavaScript bridge. Free for any use, with no paid tier.

Highlights

• Candlestick chart — eight chart types, Heikin-Ashi, Renko, Kagi and more, four price scales, sessions, comparison overlays and bar replay.
• 31 indicators — overlays and stacked panes, each a configured instance, with higher-timeframe values that never repaint.
• 29 drawing tools — Fibonacci, channels, patterns and positions, with an editor, undo/redo, alerts and JSON persistence.
• 55 more chart widgets — series, pie, heatmap, treemap, sankey, depth, order flow, volatility and futures curves, risk and portfolio charts, the charts a backtest report is made of, and charts for training and serving language models.
• Fully themeable — ChartStyle, ChartColors and ChartTranslations.

See the full feature list and the gallery.

Note

This package has grown large. To keep it fast and focused, the next update will split it into separate packages. ohlcv_chart will keep only the candlestick (OHLCV) chart, its indicators and its drawing tools; the other chart widgets will move to their own packages.

Installation

dependencies:
  material_ui: ">=1.0.0 <2.0.0"
  ohlcv_chart: ">=3.2.0 <4.0.0"

Requires Dart 3.12 and Flutter 3.44 or later. Widgets are built on the material_ui package rather than the Material library that used to ship in the Flutter SDK, so import package:material_ui/material_ui.dart where your app imported package:flutter/material.dart.

Quick start

Pass a list of KLineEntity to KChartWidget. Call DataUtil.calculate first so the indicator values are populated:

import 'package:ohlcv_chart/ohlcv_chart.dart';

DataUtil.calculate(candles);

KChartWidget(
  candles,
  ChartColors(),
  timeFrame: const Duration(minutes: 15),
  indicators: [MaIndicator(period: 20), MacdIndicator()],
  fixedLength: 2,
);

The example app demonstrates every option in the package.

Charts

Screenshots and a reference page for every chart are in the gallery.

Candlestick, indicators and drawing

• Chart types — candles, Heikin-Ashi, Renko, Kagi and more, symbol comparison, bar replay
• Indicators — 31 overlays and stacked panes, panes
• Drawing tools and trading — 29 drawing tools, line editor, orders and positions, event marks

Business and statistical

• Series, pie, radar, heatmap and depth — series, pie and radar, heatmap, depth
• Dashboards and reports — treemap, sunburst, sankey, chord, marimekko, stream, parallel coordinates, slope and bump, bubble, box plot, histogram, violin and ridgeline, dumbbell, bullet, gauge, waffle, funnel, sparkline grid
• Progress and goals — progress bars and progress cards

Trading analysis

• Order flow and derivatives — market profile, footprint, order-book heatmap, cumulative delta, liquidity map, open interest and funding, options payoff, volatility curves, volatility surface, pair spread, futures curve
• Backtests and results — equity curve, Monte Carlo fan, R-multiple, trade timeline, seasonality, calendar, waterfall, MAE / MFE, value at risk, efficient frontier, activity clock

Models, tokens and AI

• Training — training curves, scaling laws, hyperparameter sweep, training timeline
• Evaluation — benchmark matrix, model cost against quality, evaluation breakdown
• Serving and tokens — latency bands, token usage, token heatmap

Axes and interaction

• Axes, sessions and layout — price axes, date axis, sessions, sizing, theming
• Interaction — legend and crosshair, long-press readout, driving the chart

Documentation

• Documentation index — a reference page per feature
• Features and gallery
• Changelog — what changed in each release
• Migrating from 1.x and from fl_chart and candlesticks

Contributing

Bug reports and pull requests are welcome — see CONTRIBUTING.md. If the package is useful to you, a star on the repository or a like on pub.dev helps others find it.

License

Released under the MIT License. See LICENSE. The rendering core is derived from the open-source k_chart package and has since been substantially extended.