ohlcv_chart 1.1.0

Candlestick and market-depth charts for Flutter, with MA, BOLL and SAR overlays, MACD, KDJ, RSI, WR and CCI sub-charts, signal markers and interactive drawing tools.

1.1.0

Drawing tools

• Reworked the line editor. Selecting a drawn line now opens a floating, draggable toolbar with a colour swatch grid and opacity slider, thickness presets plus a fine slider, solid/dashed/dotted stroke previews, an inline label field, and lock, delete and done buttons. It replaces the two bare SimpleDialog pickers, and its panels are hosted in the app overlay, so their sliders and text field no longer compete with the chart's pan and zoom.
• New DrawingStyle, passed as KChartWidget.drawingStyle: the colours, thicknesses and stroke styles on offer, which controls appear, the toolbar's colours, radius, padding, axis, icon size and start position, the drawn lines' handle and label geometry, dash lengths, and how close to a line a tap has to land to select it.
• New DrawingTranslations, reachable as ChartTranslations.drawing, covering every label and tooltip in the editor.
• LineStyle - solid, dashed or dotted - on ChartLine, alongside a ChartLine.opacity accessor backed by the colour's alpha channel. isDashed still reads and writes as before.
• Editing a line now reports it: restyling, renaming or dragging one fires the matching onAdd* callback, which previously only fired when a line was first placed, so those changes could not be persisted.
• A trend line can be selected by its stroke rather than only its two ends, and dragging it there moves the whole line.
• DepthChartStyle and DepthChartColors are exported, so the depth chart can actually be themed.

Fixed:

• The long-press readout no longer overflows. Its rows shrink and ellipsise, and the card sizes itself to its content between the new infoDialogWidth and infoDialogMaxWidth, capped by the chart's own width. Long translations and intraday timestamps used to run past its fixed 130 pixels.
• Drawn lines keep the thickness they were given at every zoom level, and their drag handles stay circular. Both were painted inside the chart's horizontal scale, which stretched them.
• A vertical line's label is painted once, and only when showLabel is set. It was drawn twice, and the first pass ignored the flag.
• A vertical line is no longer overlaid by a hard-coded 1-pixel solid line that ignored its colour, thickness and stroke style.
• Line labels are padded evenly; the right side had twice the padding of the left.

Indicators

Indicators are now configured instances rather than enum flags, so the same kind can be on the chart several times with different settings and colours.

• Breaking: mainStateLi, secondaryStateLi and maDayList are replaced by a single indicators list of Indicator instances — MaIndicator(period: 20), AtrIndicator(period: 8), MacdIndicator(fast: 5, slow: 34, signal: 5) and so on. MainState and SecondaryState are gone. Overlays draw over the candles; the rest each take a pane, stacked in the order given.
• Several of one kind is the point: ATR(8), ATR(14) and ATR(20) are three panes, and three moving averages take three theme colours without being told.
• Every instance takes a color — or colors, one per line, for BOLL, MACD, KDJ and DMI — which overrides the ChartColors palette for that instance alone.
• An indicator is identified by its type and settings, colours deliberately excluded, so indicators.upsert(...) restyles the matching one already on the chart instead of stacking a duplicate. toggle and removeIndicator round out the list editing, and the chart itself keeps the last of any equal pair it is given.
• New indicatorCatalog describes every indicator — its settings with their ranges and defaults, and its colour slots — so an "add indicator" dialog can be built from data. IndicatorType.create builds an instance from a values map, valuesOf reads an existing one back into the form, lineLabels and defaultColors label and seed the colour pickers, and indicatorTypeOf finds the entry describing an indicator. The example app's indicator sheet is built entirely from it.
• Indicator maths moved into pure series functions that take candles and return values, shared by the indicators and by DataUtil, which still fills in the fields on each KLineEntity for the long-press readout.
• Custom indicators: subclass Indicator, give it a label, lines, settings and a compute, and the chart draws, scales, legends and labels it like any built-in one.

Twelve new indicators, all of them configurable and repeatable like the rest:

• Overlays: SupertrendIndicator (an ATR stop that changes colour when it flips), KeltnerIndicator, DonchianIndicator and IchimokuIndicator, whose cloud is shaded between its two spans and whose spans and lagging line carry the usual displacement.
• Swing readers, all driven by one depth — the percentage move that ends a swing: ZigZagIndicator draws the legs, FibonacciIndicator retraces the last one so the levels follow the market instead of being placed by hand, and ElliottWaveIndicator labels the pivots 1-5 then A-C. The wave count is a reading of the swings rather than a rules-checked Elliott count.
• Panes: StochRsiIndicator (with 20/80 guides), RocIndicator, TrixIndicator, VolumeMaIndicator and AwesomeIndicator, whose bars take the up and down colours by whether momentum grew.
• Three new line shapes behind them, available to any indicator: IndicatorShape.pivotLine strokes straight across the candles that have no value, IndicatorShape.markers draws a dot with the indicator's own text beside it through markerLabel, and fills shades the area between two lines with fillColor deciding its colour from which line is on top.
• The swing readers size their threshold from the candles by default, rather than a fixed percentage: depth: 0 — now the default — aims for roughly eight legs across the data, so a zigzag reads the same on a quiet intraday chart as on a volatile daily one. A fixed 5% drew nothing at all on a market that never moved 5%. Pass any positive depth to set it yourself; the label says auto when it is worked out.
• New ChartColors entries for each of them: keltnerColor, donchianColor, conversionColor, baseColor, spanAColor, spanBColor, laggingColor, stochRsiColor, rocColor, trixColor, volumeMaColor, awesomeColor, zigzagColor, fibonacciColor and waveColor.

Depth chart

The depth chart draws the same book four ways, and can say what is resting on each rung rather than only the running total.

• New mode, a DepthChartMode: cumulative — the curves it has always drawn and still the default — histogram, one bar per level sized by what rests on that rung alone, combined for both at once, and ladder, a numeric table of price, size and running total with a bar behind each row.
• New DepthLadder, the widget behind that last mode, usable on its own to put the numbers beside a chart rather than instead of it. levels sets how many rungs a side it lists and barsShowTotal whether its bars follow the running total or each rung's own size.
• New scale, a DepthScale: linear, log for a book whose far side dwarfs the near one, or percent to label the axis as a share of the deepest total.
• New zoom, which keeps only the levels within that fraction of the mid price. A zoom so tight that nothing would be left falls back to the whole book rather than to an empty chart.
• New DepthBook and DepthLevel: each rung's own size recovered from the cumulative curves by differencing, so nothing extra has to be passed in. DepthBook.fromCurves is public for callers who want the levels themselves.
• The long-press readout names the size resting on the rung under the finger as well as the running total out to it, and its dot follows whatever the mode draws.
• New DepthChartTranslations entries — size, total, bids, asks and spread — and DepthChartStyle.barWidthFactor, ladderRowHeight and ladderFontSize.

Rendering

Six new indicators, a reworked look, and a demo that exercises all of it.

• New main-chart overlays: EMA — exponential moving averages over the same periods as MA, sharing its palette — and VWAP, accumulated over the candles you pass.
• New sub-charts: ATR (14), OBV, MFI (14, with 20/80 guides) and DMI (+DI, −DI and ADX, with the 20 guide). Each has its own ChartColors entry, and DataUtil.calculate fills them in alongside the existing indicators; calcEMA, calcVWAP, calcATR, calcOBV, calcMFI and calcDMI are public if you want a subset.
• The main chart's price range now stretches to hold EMA and VWAP, the way it already did for BOLL and SAR, so a lagging average is never clipped.
• mBaseHeight is optional. Left unset, the candle area takes whatever height the panes below it do not need, so the chart fills its box instead of painting past it; in a box with no height to divide it falls back to 360. Pane heights are available as BaseDimension.volumeHeight, secondaryPaneHeight and legendRowHeight.
• Rendering polish, all of it configurable: pane separators in their own colour, price-axis labels padded and set on a pill so they stay readable over candles, indicator legends on rounded translucent pills, optional hollow rising candles, a dashed "now price" line in the up/down colours with its tag on the side the axis labels are not using, high/low markers drawn with a leader line, a crosshair with configurable dash lengths, and a watermark placed by alignment and tinted rather than pinned to a fixed offset.
• New ChartStyle fields: hollowUpCandles, gridStrokeWidth, separatorWidth, axisLabelBackground, axisLabelPadding, labelCornerRadius, legendPadding, legendSpacing, crossDashLength, crossDashGap, nowPriceDashed, watermarkAlignment, watermarkScale. New ChartColors fields: separatorColor, axisLabelBgColor, legendBgColor, watermarkColor, plus the new indicators' colours.
• DepthEntity.bids and DepthEntity.asks build cumulative depth curves from raw order-book rungs, sorting by price and accumulating outwards from the mid.
• VerticalTextAlignment is exported, so verticalTextAlignment can be named.
• The example is now a full tour: every overlay and pane, drawing tools with two editor styles, live ticks that roll the candle over, onLoadMore pagination, signal markers, both readout styles plus a custom builder, light and dark palettes, a German localisation, filled and hollow candles, and the depth chart — laid out side by side on a wide window and stacked on a narrow one.

Fixed:

• A pivot line — a zigzag, and anything else defined only at its corners — draws the leg that crosses the visible window. The painter walked only the candles in view, so a swing whose two ends sat either side of the window drew nothing at all, and the line vanished as soon as it was zoomed into.
• An indicator with no values in view no longer hands an empty path to the canvas.
• isTapShowInfoDialog does something. The tap flag it depends on was never set, so the readout only ever opened on a long press; a tap now opens it, moves it, and closes it again.
• The crosshair's price and date labels no longer appear without the crosshair itself. Both are shown together, and both are suppressed while a line is being drawn or dragged, instead of the labels being drawn whenever a long press happened and the lines being hidden for good as soon as the drawing tools were enabled.
• The line above the volume pane is no longer amber: the separator paint had a hard-coded Colors.amber that no theme could reach.
• The vertical grid draws the number of columns asked for. Both the main chart and the volume pane looped over a pixel distance instead of the column count, drawing around 120 lines per frame, nearly all of them off screen.
• The "now price" line uses nowPriceUpColor and nowPriceDnColor, which existed for it but went unused — it was drawn in the high/low marker colours, near-black by default.
• The watermark is centred in the candle area rather than pinned to a hard-coded offset that put it off screen on small charts.
• The candle area no longer collapses in a box shorter than the panes ask for; the panes shrink to fit instead of overlapping the candles.
• The bottom price-axis label is left out when a pane sits below the main chart, where it used to be drawn on top of that pane's legend.
• NumberUtil.formatCompact keeps the sign of negative values, which OBV needs.

1.0.0

• Initial release, extracted from an internal application module.
• KChartWidget: candlestick and line rendering, pinch zoom, fling scroll, long-press crosshair and info dialog, "now price" line with candle countdown, and an SVG watermark.
• Main-chart overlays MA, BOLL and SAR, selectable as a set.
• Secondary charts MACD, KDJ, RSI, WR and CCI, stacked.
• Drawing tools for trend, horizontal and vertical lines, with selection, dragging, colour and thickness editing, and add/remove callbacks.
• Buy/sell SignalEntity markers.
• DepthChart for bid/ask cumulative market depth with a long-press readout.
• ChartStyle, ChartColors and ChartTranslations for full visual and text customisation; DepthChartStyle, DepthChartColors and DepthChartTranslations for the depth chart.
• DataUtil.calculate computes every indicator in place over a candle list.
• Runs on iOS, Android, web, Windows, macOS and Linux. The zoom slider now appears only where there is no pinch gesture — web and desktop — where before a always-true platform check rendered it on mobile as well.

Fixed while extracting the module:

• DataUtil.calculate no longer throws on an empty candle list, so the chart can be built before the first candles arrive.
• Secondary charts scale to their true maximum when an indicator stays below zero. MACD and CCI in a sustained decline previously scaled against zero, because the running maximum was seeded with double.minPositive — a tiny positive number rather than a lower bound.
• SAR resets its acceleration factor identically on both trend reversals; the up-to-down reversal previously restarted one step too fast.
• The "now price" countdown timer starts and stops when showNowPrice changes, instead of only being read once when the chart is first built.