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QCustomCandlestickChart

Pro widget

QCustomCandlestickChart ships in Custom Widgets Pro. The free package under GPLv3 does not include it.

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QCustomCandlestickChart

A painted OHLC / candlestick price chart.

Each candle is one period: a filled body spanning open->close and a wick spanning low->high. Candles are coloured by direction - up when close >= open, down otherwise - which is the whole point of the form.

Rendered entirely with QPainter and NO QtCharts dependency. That is deliberate and load-bearing: Qt Charts is GPLv3-or-commercial with no LGPL option, so anything built on it cannot ship inside a proprietary wheel. This widget stays clean.

Data goes in with setData([(open, high, low, close), ...]) in code, or the ohlcCsv property in Qt Designer ("o,h,l,c;o,h,l,c;..."), following the valuesCsv convention used by the other painted charts.

Emits candleHovered(int) and candleClicked(int); -1 means "nothing".

At a glance

TierPro
Importfrom Custom_Widgets.QCustomCandlestickChart import QCustomCandlestickChart
Qt DesignerYes — drag it from the palette

Quick start

from Custom_Widgets.QCustomCandlestickChart import QCustomCandlestickChart

widget = QCustomCandlestickChart()

Dark theme

Colours come from the design tokens, so the widget follows the app theme with no extra work.

QCustomCandlestickChart in dark theme

Properties

Every property below is settable in code and in Qt Designer.

PropertyTypeDefault
ohlcCsvstring
labelsCsvstring
showGridboolTrue
showPriceAxisboolTrue
showLabelsboolTrue
showTooltipboolTrue
hollowUpCandlesboolFalse
candleWidthRatiofloat0.62
gridLinesint4
pricePrecisionint2
upColorcolor#16a34a
downColorcolor#dc2626
wickColorcolor#64748b
gridColorcolor#e2e8f0
axisTextColorcolor#64748b
tooltipBackgroundColorcolor
tooltipTextColorcolor

Signals

Signal
candleClicked(int)
candleHovered(int)

Methods

MethodDescription
axisTextColor(*args, **kwargs)Axis text color.
candleAt(pos)Index of the candle under a point, or -1.
candleClicked(...)Candle clicked.
candleHovered(...)Candle hovered.
candleWidthRatio(*args, **kwargs)Candle width ratio.
count()Count.
data()Data.
downColor(*args, **kwargs)Down color.
gridColor(*args, **kwargs)Grid color.
gridLines(*args, **kwargs)Grid lines.
hollowUpCandles(*args, **kwargs)Hollow up candles.
labels()Labels.
labelsCsv(*args, **kwargs)Labels csv.
ohlcCsv(*args, **kwargs)Ohlc csv.
pricePrecision(*args, **kwargs)Price precision.
priceRange()(low, high) across every candle, or (0.0, 1.0) when empty.
setData(data, labels=None)Replace every candle. Each item is (open, high, low, close).
setLabels(labels)Set the labels.
showGrid(*args, **kwargs)Show the grid.
showLabels(*args, **kwargs)Show the labels.
showPriceAxis(*args, **kwargs)Show the price axis.
showTooltip(*args, **kwargs)Show the tooltip.
tooltipBackgroundColor(*args, **kwargs)Tooltip background color.
tooltipTextColor(*args, **kwargs)Tooltip text color.
upColor(*args, **kwargs)Up color.
wickColor(*args, **kwargs)Wick color.

Theming

Colours come from the design tokens, so they follow the active theme. Roles used: success, destructive, outline, on-surface.

See Design tokens.

Runnable example

A complete app using this widget lives at examples/PySide6/QCustomCandlestickChart/main.py.

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