feat: add a new chart type - column

Sources/FioriCharts/Charts/ColumnChart/ColumnChart.swift

@@ -0,0 +1,89 @@
+//
+//  ColumnChart.swift
+//  FioriCharts
+//
+//  Created by Xu, Sheng on 6/3/20.
+//
+
+import SwiftUI
+
+let ColumnGapFraction: CGFloat = 0.333333
+
+struct ColumnChart: View {
+    @ObservedObject var model: ChartModel
+
+    public init(_ chartModel: ChartModel) {
+        self.model = chartModel
+    }
+
+    var body: some View {
+        XYAxisChart(model,
+                    axisDataSource: ColumnAxisDataSource(),
+                    chartView: ColumnView(model),
+                    indicatorView: ColumnIndicatorView(model))
+    }
+}
+
+class ColumnAxisDataSource: DefaultAxisDataSource {
+    override func xAxisLabels(_ model: ChartModel, rect: CGRect) -> [AxisTitle] {
+        return xAxisGridLineLabels(model, rect: rect, isLabel: true)
+    }
+
+    override func xAxisGridlines(_ model: ChartModel, rect: CGRect) -> [AxisTitle] {
+        return xAxisGridLineLabels(model, rect: rect, isLabel: false)
+    }
+
+    func xAxisGridLineLabels(_ model: ChartModel, rect: CGRect, isLabel: Bool) -> [AxisTitle] {
+        var ret: [AxisTitle] = []
+        let maxDataCount = model.numOfCategories(in: 0)
+        let startIndex = 0
+        let endIndex = maxDataCount - 1
+
+        if endIndex < 0 {
+            return ret
+        }
+
+        let columnXIncrement = 1.0 / (CGFloat(maxDataCount) - ColumnGapFraction / (1.0 + ColumnGapFraction))
+        let clusterWidth = columnXIncrement / (1.0 + ColumnGapFraction)
+        let labelsIndex = model.categoryAxis.labelLayoutStyle == .allOrNothing ? Array(startIndex ... endIndex) : (startIndex != endIndex ? [startIndex, endIndex] : [startIndex])
+
+        for (index, i) in labelsIndex.enumerated() {
+            var x = rect.origin.x + (columnXIncrement * CGFloat(i) + clusterWidth / 2.0) * rect.size.width
+
+            let title = ChartUtility.categoryValue(model, categoryIndex: i) ?? ""
+            if model.categoryAxis.labelLayoutStyle == .range && isLabel {
+                let size = title.boundingBoxSize(with: model.categoryAxis.labels.fontSize)
+                if index == 0 {
+                    x = rect.origin.x + min(size.width, (rect.size.width - 2) / 2) / 2
+                } else {
+                    x = rect.origin.x + (columnXIncrement * CGFloat(i) + clusterWidth) * rect.size.width - min(size.width, (rect.size.width - 2) / 2) / 2
+                }
+            }
+
+            ret.append(AxisTitle(index: i,
+                                 title: title,
+                                 pos: CGPoint(x: x, y: 0)))
+        }
+
+        return ret
+    }
+}
+
+// swiftlint:disable force_cast
+struct ColumnChart_Previews: PreviewProvider {
+    static var previews: some View {
+        let models: [ChartModel] = Tests.lineModels.map {
+           let model = $0.copy() as! ChartModel
+           model.chartType = .column
+           return model
+        }
+
+        return Group {
+            ForEach(models) {
+                ColumnChart($0)
+                    .frame(width: 330, height: 220, alignment: .topLeading)
+                    .previewLayout(.sizeThatFits)
+            }
+        }
+    }
+}

Sources/FioriCharts/Charts/ColumnChart/ColumnIndicatorView.swift

@@ -0,0 +1,41 @@
+//
+//  ColumnIndicatorView.swift
+//  FioriCharts
+//
+//  Created by Xu, Sheng on 6/3/20.
+//
+
+import SwiftUI
+
+struct ColumnIndicatorView: View {
+    @ObservedObject var model: ChartModel
+    @Environment(\.colorScheme) var colorScheme
+    @Environment(\.layoutDirection) var layoutDirection
+
+    init(_ model: ChartModel) {
+        self.model = model
+    }
+
+    var body: some View {
+        Text(" ")
+    }
+}
+
+// swiftlint:disable force_cast
+struct ColumnSelectionView_Previews: PreviewProvider {
+    static var previews: some View {
+        let models: [ChartModel] = Tests.lineModels.map {
+           let model = $0.copy() as! ChartModel
+           model.chartType = .column
+           return model
+        }
+
+        return Group {
+            ForEach(models) {
+                ColumnIndicatorView($0)
+                    .frame(width: 330, height: 220, alignment: .topLeading)
+                    .previewLayout(.sizeThatFits)
+            }
+        }
+    }
+}

Sources/FioriCharts/Charts/ColumnChart/ColumnView.swift

@@ -0,0 +1,186 @@
+//
+//  ColumnView.swift
+//  FioriCharts
+//
+//  Created by Xu, Sheng on 6/3/20.
+//
+
+import SwiftUI
+
+struct ColumnView: View {
+    @ObservedObject var model: ChartModel
+    @Environment(\.colorScheme) var colorScheme
+
+    init(_ model: ChartModel) {
+        self.model = model
+    }
+
+    var body: some View {
+        GeometryReader { proxy in
+            self.makeBody(in: proxy.frame(in: .local))
+        }
+    }
+
+    func makeBody(in rect: CGRect) -> some View {
+        let tickValues = model.numericAxisTickValues
+        let maxDataCount = model.numOfCategories(in: 0)
+        let columnXIncrement = 1.0 / (CGFloat(maxDataCount) - ColumnGapFraction / (1.0 + ColumnGapFraction))
+        let clusterWidth = columnXIncrement / (1.0 + ColumnGapFraction)
+        let clusterSpace: CGFloat = rect.size.width * (1.0 - clusterWidth * CGFloat(maxDataCount)) / CGFloat(max((maxDataCount - 1), 1))
+
+        let plotData = generateClusteredPlotData()
+
+        return VStack(alignment: .center, spacing: 0) {
+            if plotData.isEmpty {
+                NoDataView()
+            } else {
+                // positive value columns and their value column lables
+                HStack(alignment: .bottom, spacing: clusterSpace) {
+                    // positive values
+                    if tickValues.plotMinimum >= 0 {
+                        ForEach(plotData, id: \.self) { series in
+                            HStack(alignment: .bottom, spacing: 0) {
+                                ForEach(series, id: \.self) { item in
+                                    Rectangle()
+                                        .fill(self.model.seriesAttributes[item.seriesIndex].palette.fillColor.color(self.colorScheme))
+                                        .frame(width: item.rect.size.width * rect.size.width, height: item.rect.size.height * rect.size.height)
+                                }
+                            }
+                        }
+                    } else if tickValues.plotMaximum <= 0 { // negative values
+                        ForEach(plotData, id: \.self) { series in
+                            HStack(alignment: .bottom, spacing: 0) {
+                                ForEach(series, id: \.self) { item in
+                                    VStack(alignment: .center, spacing: 0) {
+                                        Rectangle()
+                                        .fill(self.model.seriesAttributes[item.seriesIndex].palette.fillColor.color(self.colorScheme))
+                                        .frame(width: item.rect.size.width * rect.size.width, height: item.rect.size.height * rect.size.height)
+                                        Spacer(minLength: 0)
+                                    }
+                                }
+                            }
+                        }
+                    } else { // mixed values
+                        ForEach(plotData, id: \.self) { series in
+                            HStack(alignment: .bottom, spacing: 0) {
+                                ForEach(series, id: \.self) { item in
+                                    VStack(spacing: 0) {
+                                        // positive area
+                                        VStack(spacing: 0) {
+                                            Spacer(minLength: 0)
+                                                Rectangle()
+                                                    .fill(self.model.seriesAttributes[item.seriesIndex].palette.fillColor.color(self.colorScheme))
+                                                    .frame(width: item.rect.size.width * rect.size.width, height: self.columnHeight(from: item, isPositiveArea: true) * rect.size.height)
+                                        }.frame(height: (1 - tickValues.plotBaselinePosition) * rect.size.height)
+
+                                        // negative area
+                                        VStack(spacing: 0) {
+                                            Rectangle()
+                                                .fill(self.model.seriesAttributes[item.seriesIndex].palette.fillColor.color(self.colorScheme))
+                                                .frame(width: item.rect.size.width * rect.size.width,
+                                                       height: self.columnHeight(from: item, isPositiveArea: false) * rect.size.height)
+                                            Spacer(minLength: 0)
+                                        }.frame(height: tickValues.plotBaselinePosition * rect.size.height)
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    func columnHeight(from rectData: ChartPlotRectData, isPositiveArea: Bool) -> CGFloat {
+        if (rectData.value >= 0 && isPositiveArea) || (rectData.value < 0 && !isPositiveArea) {
+            return rectData.rect.size.height
+        } else {
+            return 0
+        }
+    }
+
+    func generateClusteredPlotData() -> [[ChartPlotRectData]] {
+        var result: [[ChartPlotRectData]] = []
+        let seriesCount = model.numOfSeries()
+        let maxDataCount = model.numOfCategories(in: 0)
+
+        let columnXIncrement = 1.0 / (CGFloat(maxDataCount) - ColumnGapFraction / (1.0 + ColumnGapFraction))
+        let clusterWidth = columnXIncrement / (1.0 + ColumnGapFraction)
+        let columnWidth = clusterWidth / CGFloat(seriesCount)
+
+        let tickValues = model.numericAxisTickValues
+        //        let minValue = tickValues.plotMinimum
+        //        let maxValue = tickValues.plotMaximum
+        let yScale = tickValues.plotScale
+        let baselinePosition = tickValues.plotBaselinePosition
+        let baselineValue = tickValues.plotBaselineValue
+        let corruptDataHeight = yScale / 1000
+
+        var clusteredX: CGFloat
+        //
+        // Loop through data points
+        //
+        for categoryIndex in 0 ..< maxDataCount {
+            var seriesResult: [ChartPlotRectData] = []
+
+            //
+            // Loop through series
+            //
+            for seriesIndex in 0 ..< seriesCount {
+                //
+                // Calculate and define clustered column x positions.
+                //
+                clusteredX = columnXIncrement * CGFloat(categoryIndex)
+                clusteredX += columnWidth * CGFloat(seriesIndex)
+                var columnHeight = corruptDataHeight
+                var clusteredY = baselinePosition
+                var rawValue: CGFloat = 0
+                //
+                // Fetch value
+                //
+                let value = model.plotItemValue(at: seriesIndex, category: categoryIndex, dimension: 0)
+
+                if let val = value {
+                    rawValue = CGFloat(val)
+                    if val >= 0.0 {
+                        columnHeight = yScale * (CGFloat(val) - baselineValue)
+                    } else {
+                        columnHeight = -yScale * (CGFloat(val) - baselineValue)
+                        clusteredY = baselinePosition - columnHeight
+                    }
+                }
+
+                seriesResult.append(ChartPlotRectData(seriesIndex: seriesIndex,
+                                                      categoryIndex: categoryIndex,
+                                                      value: rawValue,
+                                                      x: clusteredX,
+                                                      y: clusteredY,
+                                                      width: columnWidth,
+                                                      height: columnHeight))
+            }
+
+            result.append(seriesResult)
+        }
+
+        return result
+    }
+}
+
+// swiftlint:disable force_cast
+struct ColumnView_Previews: PreviewProvider {
+    static var previews: some View {
+        let models: [ChartModel] = Tests.lineModels.map {
+            let model = $0.copy() as! ChartModel
+            model.chartType = .column
+            return model
+        }
+
+        return Group {
+            ForEach(models) {
+                ColumnView($0)
+                    .frame(width: 330, height: 220, alignment: .topLeading)
+                    .previewLayout(.sizeThatFits)
+            }
+        }
+    }
+}