Added Bar Gradient

Cartfile.resolved

@@ -1 +1 @@
-github "facebook/ios-snapshot-test-case" "ed4e6a6e81bfb69a5223156e6c3d389a416cf6e3"
+github "facebook/ios-snapshot-test-case" "3efc829601128f7d9306e8e58db04d32594b62ce"

ChartsDemo-iOS/Swift/DemoBaseViewController.swift

@@ -48,6 +48,8 @@ enum Option {
     case toggleYLabels
     case toggleRotate
     case toggleHighlightCircle
+    // VericalBarChart
+    case toggleBarGradient
 
     var label: String {
         switch self {
@@ -89,6 +91,8 @@ enum Option {
         case .toggleYLabels: return "Toggle Y-Labels"
         case .toggleRotate: return "Toggle Rotate"
         case .toggleHighlightCircle: return "Toggle highlight circle"
+        // VericalBarChart
+        case .toggleBarGradient: return "Toggle Bar Gradient"
         }
     }
 }

ChartsDemo-iOS/Swift/Demos/AnotherBarChartViewController.swift

@@ -31,7 +31,8 @@ class AnotherBarChartViewController: DemoBaseViewController {
                         .saveToGallery,
                         .togglePinchZoom,
                         .toggleData,
-                        .toggleBarBorders]
+                        .toggleBarBorders,
+                        .toggleBarGradient]
 
         chartView.delegate = self
 
@@ -87,7 +88,20 @@ class AnotherBarChartViewController: DemoBaseViewController {
     }
 
     override func optionTapped(_ option: Option) {
-        super.handleOption(option, forChartView: chartView)
+        switch option {
+        case .toggleBarGradient:
+            for set in chartView.data!.dataSets as! [BarChartDataSet] {
+                if set.barGradientColors == nil {
+                    set.barGradientColors = ChartColorTemplates.gradients()
+                    set.barGradientOrientation = .horizontal
+                } else {
+                    set.barGradientColors = nil
+                }
+            }
+            chartView.notifyDataSetChanged()
+        default:
+            super.handleOption(option, forChartView: chartView)
+        }
     }
 
     // MARK: - Actions

ChartsDemo-iOS/Swift/Demos/BarChartViewController.swift

@@ -31,7 +31,8 @@ class BarChartViewController: DemoBaseViewController {
                         .saveToGallery,
                         .togglePinchZoom,
                         .toggleData,
-                        .toggleBarBorders]
+                        .toggleBarBorders,
+                        .toggleBarGradient]
 
         self.setup(barLineChartView: chartView)
 
@@ -139,7 +140,19 @@ class BarChartViewController: DemoBaseViewController {
     }
 
     override func optionTapped(_ option: Option) {
-        super.handleOption(option, forChartView: chartView)
+        switch option {
+        case .toggleBarGradient:
+            for set in chartView.data!.dataSets as! [BarChartDataSet] {
+                if set.barGradientColors == nil {
+                    set.barGradientColors = ChartColorTemplates.gradients()
+                } else {
+                    set.barGradientColors = nil
+                }
+            }
+            chartView.notifyDataSetChanged()
+        default:
+            super.handleOption(option, forChartView: chartView)
+        }
     }
 
     // MARK: - Actions

ChartsDemo-iOS/Swift/Demos/MultipleBarChartViewController.swift

@@ -32,7 +32,8 @@ class MultipleBarChartViewController: DemoBaseViewController {
                         .togglePinchZoom,
                         .toggleAutoScaleMinMax,
                         .toggleData,
-                        .toggleBarBorders]
+                        .toggleBarBorders,
+                        .toggleBarGradient]
 
         chartView.delegate = self
 
@@ -138,7 +139,19 @@ class MultipleBarChartViewController: DemoBaseViewController {
     }
 
     override func optionTapped(_ option: Option) {
-        super.handleOption(option, forChartView: chartView)
+        switch option {
+        case .toggleBarGradient:
+            for set in chartView.data!.dataSets as! [BarChartDataSet] {
+                if set.barGradientColors == nil {
+                    set.barGradientColors = ChartColorTemplates.gradients()
+                } else {
+                    set.barGradientColors = nil
+                }
+            }
+            chartView.notifyDataSetChanged()
+        default:
+            super.handleOption(option, forChartView: chartView)
+        }
     }
 
     // MARK: - Actions

ChartsDemo-iOS/Swift/Demos/PositiveNegativeBarChartViewController.swift

@@ -33,7 +33,8 @@ class PositiveNegativeBarChartViewController: DemoBaseViewController {
                         .togglePinchZoom,
                         .toggleAutoScaleMinMax,
                         .toggleData,
-                        .toggleBarBorders]
+                        .toggleBarBorders,
+                        .toggleBarGradient]
 
         self.setup(barLineChartView: chartView)
 
@@ -109,7 +110,19 @@ class PositiveNegativeBarChartViewController: DemoBaseViewController {
     }
 
     override func optionTapped(_ option: Option) {
-        super.handleOption(option, forChartView: chartView)
+        switch option {
+        case .toggleBarGradient:
+            for set in chartView.data!.dataSets as! [BarChartDataSet] {
+                if set.barGradientColors == nil {
+                    set.barGradientColors = ChartColorTemplates.gradients()
+                } else {
+                    set.barGradientColors = nil
+                }
+            }
+            chartView.notifyDataSetChanged()
+        default:
+            super.handleOption(option, forChartView: chartView)
+        }
     }
 }
 

ChartsDemo-iOS/Swift/Demos/StackedBarChartViewController.swift

@@ -41,7 +41,8 @@ class StackedBarChartViewController: DemoBaseViewController {
                         .togglePinchZoom,
                         .toggleAutoScaleMinMax,
                         .toggleData,
-                        .toggleBarBorders]
+                        .toggleBarBorders,
+                        .toggleBarGradient]
 
 
         chartView.delegate = self
@@ -113,7 +114,19 @@ class StackedBarChartViewController: DemoBaseViewController {
     }
 
     override func optionTapped(_ option: Option) {
-        super.handleOption(option, forChartView: chartView)
+        switch option {
+        case .toggleBarGradient:
+            for set in chartView.data!.dataSets as! [BarChartDataSet] {
+                if set.barGradientColors == nil {
+                    set.barGradientColors = ChartColorTemplates.gradients()
+                } else {
+                    set.barGradientColors = nil
+                }
+            }
+            chartView.notifyDataSetChanged()
+        default:
+            super.handleOption(option, forChartView: chartView)
+        }
     }
 
     @IBAction func slidersValueChanged(_ sender: Any?) {

Source/Charts/Data/Implementations/Standard/BarChartDataSet.swift

@@ -12,9 +12,16 @@
 import Foundation
 import CoreGraphics
 
+@objc
+public enum BarGradientOrientation: Int
+{
+    case vertical
+    case horizontal
+}
 
 open class BarChartDataSet: BarLineScatterCandleBubbleChartDataSet, BarChartDataSetProtocol
 {
+
     private func initialize()
     {
         self.highlightColor = NSUIColor.black
@@ -117,6 +124,19 @@ open class BarChartDataSet: BarLineScatterCandleBubbleChartDataSet, BarChartData
     /// the alpha value (transparency) that is used for drawing the highlight indicator bar. min = 0.0 (fully transparent), max = 1.0 (fully opaque)
     open var highlightAlpha = CGFloat(120.0 / 255.0)
 
+    /// array of gradient colors [[color1, color2], [color3, color4]]
+    open var barGradientColors: [[NSUIColor]]?
+
+    open var barGradientOrientation: BarGradientOrientation = .vertical
+
+    /// - returns: The gradient colors at the given index of the DataSet's gradient color array.
+    /// This prevents out-of-bounds by performing a modulus on the gradient color index, so colours will repeat themselves.
+    open func barGradientColor(at index: Int) -> [NSUIColor]?
+    {
+        guard let gradientColors = barGradientColors else { return nil }
+        return gradientColors[index % gradientColors.count]
+    }
+
     // MARK: - NSCopying
 
     open override func copyWithZone(_ zone: NSZone?) -> AnyObject

Source/Charts/Data/Interfaces/BarChartDataSetProtocol.swift

@@ -39,4 +39,13 @@ public protocol BarChartDataSetProtocol: BarLineScatterCandleBubbleChartDataSetP
 
     /// array of labels used to describe the different values of the stacked bars
     var stackLabels: [String] { get set }
+
+    /// array of gradient colors [[color1, color2], [color3, color4]]
+    var barGradientColors: [[NSUIColor]]? { get set }
+
+    var barGradientOrientation: BarGradientOrientation { get set }
+
+    /// - returns: The gradient colors at the given index of the DataSet's gradient color array.
+    /// This prevents out-of-bounds by performing a modulus on the gradient color index, so colours will repeat themselves.
+    func barGradientColor(at index: Int) -> [NSUIColor]?
 }

Source/Charts/Renderers/BarChartRenderer.swift

@@ -318,16 +318,11 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
             guard viewPortHandler.isInBoundsLeft(barRect.origin.x + barRect.size.width) else { continue }
             guard viewPortHandler.isInBoundsRight(barRect.origin.x) else { break }
 
-            if !isSingleColor
-            {
-                // Set the color for the currently drawn value. If the index is out of bounds, reuse colors.
-                context.setFillColor(dataSet.color(atIndex: j).cgColor)
-            }
-
-            context.fill(barRect)
+            drawBar(context: context, dataSet: dataSet, index: j, barRect: barRect)
 
             if drawBorder
             {
+                context.saveGState()
                 context.setStrokeColor(borderColor.cgColor)
                 context.setLineWidth(borderWidth)
                 context.stroke(barRect)
@@ -350,6 +345,50 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
         }
     }
 
+    open func drawBar(context: CGContext, dataSet: BarChartDataSetProtocol, index: Int, barRect: CGRect)
+    {
+        context.saveGState()
+        defer { context.restoreGState() }
+
+        if let gradientColor = dataSet.barGradientColor(at: index)
+        {
+            drawGradient(context: context, barRect: barRect, gradientColors: gradientColor, orientation: dataSet.barGradientOrientation)
+        }
+        else
+        {
+            // Set the color for the currently drawn value. If the index is out of bounds, reuse colors.
+            let fillColor = dataSet.color(atIndex: index).cgColor
+            context.setFillColor(fillColor)
+            context.fill(barRect)
+        }
+    }
+
+    open func drawGradient(context: CGContext, barRect: CGRect, gradientColors: Array<NSUIColor>, orientation: BarGradientOrientation)
+    {
+        let cgColors = gradientColors.map{ $0.cgColor } as CFArray
+        let gradient = CGGradient(colorsSpace: CGColorSpaceCreateDeviceRGB(), colors: cgColors, locations: nil)
+
+        let startPoint: CGPoint
+        let endPoint: CGPoint
+
+        switch orientation
+        {
+        case .vertical:
+            startPoint = CGPoint(x: barRect.midX, y: barRect.maxY)
+            endPoint = CGPoint(x: barRect.midX, y: barRect.minY)
+
+        case .horizontal:
+            startPoint = CGPoint(x: barRect.minX, y: barRect.midY)
+            endPoint = CGPoint(x: barRect.maxX, y: barRect.midY)
+        }
+
+        let path = CGPath(rect: barRect, transform: nil)
+
+        context.addPath(path)
+        context.clip()
+        context.drawLinearGradient(gradient!, start: startPoint, end: endPoint, options: [])
+    }
+
     open func prepareBarHighlight(
         x: Double,
           y1: Double,

Source/Charts/Renderers/HorizontalBarChartRenderer.swift

@@ -259,6 +259,8 @@ open class HorizontalBarChartRenderer: BarChartRenderer
                 continue
             }
 
+            drawBar(context: context, dataSet: dataSet, index: j, barRect: barRect)
+
             if !isSingleColor
             {
                 // Set the color for the currently drawn value. If the index is out of bounds, reuse colors.

Source/Charts/Utils/ChartColorTemplates.swift

@@ -84,6 +84,14 @@ open class ChartColorTemplates: NSObject
         ]
     }
 
+    @objc open class func gradients () -> [[NSUIColor]]
+    {
+        let palette = joyful()
+        return [[palette[0], palette[1]],
+                [palette[2], palette[3]],
+                [palette[4], palette[0]]]
+    }
+
     @objc open class func colorFromString(_ colorString: String) -> NSUIColor
     {
         let leftParenCharset: CharacterSet = CharacterSet(charactersIn: "( ")

Source/Charts/Utils/Platform.swift

@@ -661,5 +661,5 @@ public typealias NSUIGestureRecognizerState = UIGestureRecognizer.State
     {
 		return NSUIScreen.main
 	}
-    
+
 #endif