CandlestickChart

The main chart view. A plain SwiftUI View, so it composes with .frame(...), .padding(...) and everything else you'd expect.

public struct CandlestickChart: View

Initializer

public init(_ candles: [Candle], state: CandleChartState? = nil)

Parameter	Description
candles	The series to draw, sorted oldest first.
state	Pass your own CandleChartState to control scrolling/zoom from outside the chart. Omit it and the chart manages its own state internally.

CandlestickChart(candles)
CandlestickChart(candles, state: chartState)

Modifiers

Every modifier below returns a new CandlestickChart, so they chain like any other SwiftUI modifier.

.candleChartStyle(_:)

public func candleChartStyle(_ style: CandleChartStyle) -> CandlestickChart

Colors and candle appearance. See CandleChartStyle for every property and the built-in presets.

CandlestickChart(candles).candleChartStyle(.redUp)

.indicators(_:)

public func indicators(_ indicators: [ChartIndicator]) -> CandlestickChart

Line overlays such as moving averages, plus oscillators in their own panes. Values are cached and only recomputed when the data changes. See ChartIndicator.

CandlestickChart(candles).indicators([.sma(20), .ema(50)])

.volumeVisible(_:)

public func volumeVisible(_ visible: Bool = true) -> CandlestickChart

Shows volume bars beneath the candles. On by default.

CandlestickChart(candles).volumeVisible(false)

.headerVisible(_:)

public func headerVisible(_ visible: Bool = true) -> CandlestickChart

Shows the price readout above the chart. On by default.

CandlestickChart(candles).headerVisible(false)

.priceFractionDigits(_:)

public func priceFractionDigits(_ digits: Int?) -> CandlestickChart

Decimal places for prices. By default this is inferred automatically from the latest close (so a $45,000 asset and a $0.003 asset both get a sensible number of decimals without you specifying anything).

CandlestickChart(candles).priceFractionDigits(4)

.onCrosshairChange(_:)

public func onCrosshairChange(_ action: @escaping (Candle?) -> Void) -> CandlestickChart

Called when the long-pressed candle changes, and with nil when the finger lifts.

CandlestickChart(candles)
    .onCrosshairChange { candle in
        selectedCandle = candle
    }

.onReachOldestCandle(_:)

public func onReachOldestCandle(_ action: @escaping () -> Void) -> CandlestickChart

Called when the user scrolls near the oldest loaded candle — prepend older candles to your array in response. The handler runs once per data size, so it won't fire repeatedly while a request is in flight.

CandlestickChart(candles)
    .onReachOldestCandle {
        Task { await loadHistory() }
    }

.drawings(_:)

public func drawings(_ drawings: Binding<[Drawing]>) -> CandlestickChart

The app-owned array of trend lines, rectangles, Fibonacci retracements and other annotations the person draws on the chart — the same "app owns the array" shape .indicators([...]) already uses. Omitting this modifier means drawing tools cost nothing at all: no extra Canvas layer, no gesture-mode branching. See the Drawing Tools guide and the Drawing API reference.

CandlestickChart(candles).drawings($drawings)

.defaultDrawingStyle(_:)

public func defaultDrawingStyle(_ style: DrawingStyle) -> CandlestickChart

The color, line width, dash and fill opacity a newly created drawing starts with. Defaults to DrawingStyle()'s neutral blue. To recolor a drawing that already exists — including the currently selected one — mutate its style directly in your own .drawings(...) array instead.

CandlestickChart(candles).defaultDrawingStyle(DrawingStyle(color: .default, lineWidth: 2))

.drawingTool(_:)

public func drawingTool(_ tool: Binding<DrawingTool?>) -> CandlestickChart

Which drawing tool is active, or nil for the chart's ordinary pan/zoom/crosshair behavior (the default). While a tool is set, a one-finger drag creates a drawing of that kind instead of panning the chart, and pinch/long-press are suppressed; releasing commits the drawing and the tool stays selected for the next one. Requires .drawings(...) to also be attached.

CandlestickChart(candles)
    .drawings($drawings)
    .drawingTool($activeTool)

.selectedDrawing(_:)

public func selectedDrawing(_ selection: Binding<UUID?>) -> CandlestickChart

Mirrors which drawing's id is currently selected (by tapping it, in cursor mode), or nil when nothing is selected. One-way, chart → app: use it to show your own inspector or "Delete" button. Deletion itself is just drawings.removeAll { $0.id == id } on your own .drawings(...) binding. Optional — omit it if you don't need to react to selection.

CandlestickChart(candles)
    .drawings($drawings)
    .selectedDrawing($selectedDrawingID)

A fuller example

CandlestickChart(candles, state: chartState)
    .candleChartStyle(CandleChartStyle(priceAxisMaterial: .ultraThinMaterial))
    .indicators([.sma(20), .ema(50), .rsi(14)])
    .volumeVisible(true)
    .drawings($drawings)
    .drawingTool($activeDrawingTool)
    .selectedDrawing($selectedDrawingID)
    .defaultDrawingStyle(DrawingStyle(color: drawingColor))
    .onReachOldestCandle { Task { await loadHistory() } }
    .onCrosshairChange { candle in selectedCandle = candle }