SwiftUICharts

A charts / plotting library for SwiftUI. Works on macOS, iOS, watchOS, and tvOS and has accessibility and Localization features built in.

Demo Project

Documentation

Working on a Version 3 with a more SwiftUI feel to the API.

Chart Types

• Line Chart

• Filled Line Chart

• Multi Line Chart

• Ranged Line Chart

• Bar Chart

• Ranged Bar Chart

• Grouped Bar Chart

• Stacked Bar Chart

• Pie Chart

• Doughnut Chart

Line Charts

Line Chart

Uses LineChartData data model.

LineChart(chartData: LineChartData)

Filled Line Chart

Uses LineChartData data model.

FilledLineChart(chartData: LineChartData)

Multi Line Chart

Uses MultiLineChartData data model.

MultiLineChart(chartData: MultiLineChartData)

Ranged Line Chart

Uses RangedLineChart data model.

RangedLineChart(chartData: RangedLineChartData)

Bar Charts

Bar Chart

Uses BarChartData data model.

BarChart(chartData: BarChartData)

Range Bar Chart

Uses RangedBarChartData data model.

RangedBarChart(chartData: RangedBarChartData)

Grouped Bar Chart

Uses GroupedBarChartData data model.

GroupedBarChart(chartData: GroupedBarChartData)

Stacked Bar Chart

Uses StackedBarChartData data model.

StackedBarChart(chartData: StackedBarChartData)

Pie Charts

Pie Chart

Uses PieChartData data model.

PieChart(chartData: PieChartData)

Doughnut Chart

Uses DoughnutChartData data model.

DoughnutChart(chartData: DoughnutChartData)

Documentation

Installation

Swift Package Manager

File > Swift Packages > Add Package Dependency...

import SwiftUICharts

If you have trouble with views not updating correctly, add .id() to your View.

LineChart(chartData: LineChartData)
    .id(LineChartData.id)

View Modifiers

• Touch Overlay

• Info Box

• Floating Info Box

• Header Box

• Legends

• Average Line

• Y Axis Point Of Interest

• X Axis Grid

• Y Axis Grid

• X Axis Labels

• Y Axis Labels

• Linear Trend Line

• Point Markers

The order of the view modifiers is some what important as the modifiers are various types of stacks that wrap around the previous views.

All Chart Types

Touch Overlay

Detects input either from touch of pointer. Finds the nearest data point and displays the relevent information where specified.

The location of the info box is set in ChartStyle -> infoBoxPlacement.

.touchOverlay(chartData: CTChartData, specifier: String, unit: TouchUnit)

• chartData: Chart data model.
• specifier: Decimal precision for labels.
• unit: Unit to put before or after the value.

Setup within Chart Data --> Chart Style

Info Box

Displays the information from Touch Overlay if InfoBoxPlacement is set to .infoBox.

The location of the info box is set in ChartStyle -> infoBoxPlacement.

.infoBox(chartData: CTChartData)

• chartData: Chart data model.

Floating Info Box

Displays the information from Touch Overlay if InfoBoxPlacement is set to .floating.

The location of the info box is set in ChartStyle -> infoBoxPlacement.

.floatingInfoBox(chartData: CTChartData)

• chartData: Chart data model.

Header Box

Displays the metadata about the chart, set in Chart Data -> ChartMetadata

Displays the information from Touch Overlay if InfoBoxPlacement is set to .header.

The location of the info box is set in ChartStyle -> infoBoxPlacement.

.headerBox(chartData: CTChartData)

Legends

Displays legends.

.legends()

Lays out markers over each of the data point.

Line and Bar Charts

Average Line

Shows a marker line at the average of all the data points.

.averageLine(chartData: CTLineBarChartDataProtocol,
             markerName: "Average",
             labelPosition: .yAxis(specifier: "%.0f"),
             lineColour: .primary,
             strokeStyle: StrokeStyle(lineWidth: 3, dash: [5,10]))

• chartData: Chart data model.
• markerName: Title of marker, for the legend.
• labelPosition: Option to display the markers’ value inline with the marker.
• labelColour: Colour of the Text.
• labelBackground: Colour of the background.
• lineColour: Line Colour.
• strokeStyle: Style of Stroke.

Y Axis Point Of Interest

Configurable Point of interest

.yAxisPOI(chartData: CTLineBarChartDataProtocol,
          markerName: "Marker",
          markerValue: 123,
          labelPosition: .center(specifier: "%.0f"),
          labelColour: Color.black,
          labelBackground: Color.orange,
          lineColour: Color.orange,
          strokeStyle: StrokeStyle(lineWidth: 3, dash: [5,10]))

• chartData: Chart data model.
• markerName: Title of marker, for the legend.
• markerValue: Value to mark
• labelPosition: Option to display the markers’ value inline with the marker.
• labelColour: Colour of the Text.
• labelBackground: Colour of the background.
• lineColour: Line Colour.
• strokeStyle: Style of Stroke.
• Returns: A new view containing the chart with a marker line at a specified value.

X Axis Grid

Adds vertical lines along the X axis.

.xAxisGrid(chartData: CTLineBarChartDataProtocol)

Setup within ChartData -> ChartStyle.

Y Axis Grid

Adds horizontal lines along the Y axis.

.yAxisGrid(chartData: CTLineBarChartDataProtocol)

Setup within ChartData -> ChartStyle.

X Axis Labels

Labels for the X axis.

.xAxisLabels(chartData: CTLineBarChartDataProtocol)

Setup within ChartData -> ChartStyle.

Y Axis Labels

Automatically generated labels for the Y axis

.yAxisLabels(chartData: CTLineBarChartDataProtocol, specifier: "%.0f")

• specifier: Decimal precision specifier.

Setup within ChartData -> ChartStyle.

yAxisLabelType:

case numeric // Auto generated, numeric labels.
case custom // Custom labels array

Custom is set from ChartData -> yAxisLabels

Linear Trend Line

A line across the chart to show the trend in the data.

.linearTrendLine(chartData: CTLineBarChartDataProtocol,
                 firstValue: Double,
                 lastValue: Double,
                 lineColour: ColourStyle,
                 strokeStyle: StrokeStyle)

Line Charts

Point Markers

Lays out markers over each of the data point.

.pointMarkers(chartData: CTLineChartDataProtocol)

Setup within Data Set -> PointStyle.

Filled Top Line

Adds an independent line on top of FilledLineChart.

.filledTopLine(chartData: LineChartData,
               lineColour: ColourStyle,
               strokeStyle: StrokeStyle)

Allows for a hard line over the data point with a semi opaque fill.

Examples

Line Chart

struct LineChartDemoView: View {
    
    let data : LineChartData = weekOfData()
    
    var body: some View {
        VStack {
            LineChart(chartData: data)
                .pointMarkers(chartData: data)
                .touchOverlay(chartData: data, specifier: "%.0f")
                .yAxisPOI(chartData: data,
                          markerName: "Step Count Aim",
                          markerValue: 15_000,
                          labelPosition: .center(specifier: "%.0f"),
                          labelColour: Color.black,
                          labelBackground: Color(red: 1.0, green: 0.75, blue: 0.25),
                          lineColour: Color(red: 1.0, green: 0.75, blue: 0.25),
                          strokeStyle: StrokeStyle(lineWidth: 3, dash: [5,10]))
                .yAxisPOI(chartData: data,
                          markerName: "Minimum Recommended",
                          markerValue: 10_000,
                          labelPosition: .center(specifier: "%.0f"),
                          labelColour: Color.white,
                          labelBackground: Color(red: 0.25, green: 0.75, blue: 1.0),
                          lineColour: Color(red: 0.25, green: 0.75, blue: 1.0),
                          strokeStyle: StrokeStyle(lineWidth: 3, dash: [5,10]))
                .averageLine(chartData: data,
                             strokeStyle: StrokeStyle(lineWidth: 3, dash: [5,10]))
                .xAxisGrid(chartData: data)
                .yAxisGrid(chartData: data)
                .xAxisLabels(chartData: data)
                .yAxisLabels(chartData: data)
                .infoBox(chartData: data)
                .headerBox(chartData: data)
                .legends(chartData: data, columns: [GridItem(.flexible()), GridItem(.flexible())])
                .id(data.id)
                .frame(minWidth: 150, maxWidth: 900, minHeight: 150, idealHeight: 250, maxHeight: 400, alignment: .center)
        }
        .navigationTitle("Week of Data")
    }
    
    static func weekOfData() -> LineChartData {
        let data = LineDataSet(dataPoints: [
            LineChartDataPoint(value: 12000, xAxisLabel: "M", description: "Monday"),
            LineChartDataPoint(value: 10000, xAxisLabel: "T", description: "Tuesday"),
            LineChartDataPoint(value: 8000,  xAxisLabel: "W", description: "Wednesday"),
            LineChartDataPoint(value: 17500, xAxisLabel: "T", description: "Thursday"),
            LineChartDataPoint(value: 16000, xAxisLabel: "F", description: "Friday"),
            LineChartDataPoint(value: 11000, xAxisLabel: "S", description: "Saturday"),
            LineChartDataPoint(value: 9000,  xAxisLabel: "S", description: "Sunday")
        ],
        legendTitle: "Steps",
        pointStyle: PointStyle(),
        style: LineStyle(lineColour: ColourStyle(colour: .red), lineType: .curvedLine))
        
        let metadata   = ChartMetadata(title: "Step Count", subtitle: "Over a Week")
        
        let gridStyle  = GridStyle(numberOfLines: 7,
                                   lineColour   : Color(.lightGray).opacity(0.5),
                                   lineWidth    : 1,
                                   dash         : [8],
                                   dashPhase    : 0)
        
        let chartStyle = LineChartStyle(infoBoxPlacement    : .infoBox(isStatic: false),
                                        infoBoxBorderColour : Color.primary,
                                        infoBoxBorderStyle  : StrokeStyle(lineWidth: 1),
                                        
                                        markerType          : .vertical(attachment: .line(dot: .style(DotStyle()))),
                                        
                                        xAxisGridStyle      : gridStyle,
                                        xAxisLabelPosition  : .bottom,
                                        xAxisLabelColour    : Color.primary,
                                        xAxisLabelsFrom     : .dataPoint(rotation: .degrees(0)),
                                        
                                        yAxisGridStyle      : gridStyle,
                                        yAxisLabelPosition  : .leading,
                                        yAxisLabelColour    : Color.primary,
                                        yAxisNumberOfLabels : 7,
                                        
                                        baseline            : .minimumWithMaximum(of: 5000),
                                        topLine             : .maximum(of: 20000),
                                        
                                        globalAnimation     : .easeOut(duration: 1))
        
        return LineChartData(dataSets       : data,
                             metadata       : metadata,
                             chartStyle     : chartStyle)
        
    }
}

Accessibility

Inside certain elements are additional tags to help describe the chart for VoiceOver.

See Localization of Accessibility

Localization

All labels support localization. There are, however, some hidden labels that are there to support VoiceOver. See Localization of Accessibility

Localization of Accessibility

See the localization demo in the Demo Project.

Voice over description of a datapoint when the user touches the area closest to the data point. The VoiceOver will say <chart title>, <data point value>, <data point description>.

"%@ <local_description_of_a_data_point>" = "%@, <Description of a data point>";

Read out before a poiMarker. The VoiceOver will say <p o i marker>, <marker legend title>, <marker value>.

"P-O-I-Marker" = "P O I Marker";
"Average" = "Average";

Voice over description of a poiMarker. The VoiceOver will say <P-O-I-Marker>, <marker legend title>, <marker value>.

"<local_marker_legend_title> %@" = "local_marker_legend_title, %@";

Read out before a axisLabel. The VoiceOver will say <axisLabel>, <marker value>.

"X-Axis-Label" = "X Axis Label";
"Y-Axis-Label" = "Y Axis Label";

Read out before a legend. The VoiceOver will say <chart type legend>, <legend title>.

"Line-Chart-Legend" = "Line Chart Legend";
"P-O-I-Marker-Legend" = "P O I Marker Legend";
"Bar-Chart-Legend" = "Bar Chart Legend";
"P-O-I-Marker-Legend" = "P O I Marker Legend";
"Pie-Chart-Legend" = "Pie Chart Legend";
"P-O-I-Marker-Legend" = "P O I Marker Legend";