Added feature for dashing legend line forms

Charts/Classes/Components/ChartLegend.swift

@@ -208,6 +208,18 @@ public class ChartLegend: ChartComponentBase
     /// The line width for forms that consist of lines
     public var formLineWidth = CGFloat(1.5)
 
+    /// Line dash configuration for shapes that consist of lines.
+    ///
+    /// This is how much (in pixels) into the dash pattern are we starting from.
+    public var formLineDashPhase: CGFloat = 0.0
+
+    /// Line dash configuration for shapes that consist of lines.
+    ///
+    /// This is the actual dash pattern.
+    /// I.e. [2, 3] will paint [--   --   ]
+    /// [1, 3, 4, 2] will paint [-   ----  -   ----  ]
+    public var formLineDashLengths: [CGFloat]?
+
     public var xEntrySpace = CGFloat(6.0)
     public var yEntrySpace = CGFloat(0.0)
     public var formToTextSpace = CGFloat(5.0)

Charts/Classes/Components/LegendEntry.swift

@@ -24,22 +24,28 @@ public class LegendEntry: NSObject
         super.init()
     }
 
-    /// - parameter label:          The legend entry text.
-    ///                             A `nil` label will start a group.
-    /// - parameter form:           The form to draw for this entry.
-    /// - parameter formSize:       Set as NaN to use the legend's default
-    /// - parameter formLineWidth:  Set as NaN to use the legend's default
-    /// - parameter formColor:      The color for drawing the form
+    /// - parameter label:                  The legend entry text.
+    ///                                     A `nil` label will start a group.
+    /// - parameter form:                   The form to draw for this entry.
+    /// - parameter formSize:               Set to NaN to use the legend's default.
+    /// - parameter formLineWidth:          Set to NaN to use the legend's default.
+    /// - parameter formLineDashPhase:      Line dash configuration.
+    /// - parameter formLineDashLengths:    Line dash configurationas NaN to use the legend's default.
+    /// - parameter formColor:              The color for drawing the form.
     public init(label: String?,
                 form: ChartLegend.Form,
                 formSize: CGFloat,
                 formLineWidth: CGFloat,
+                formLineDashPhase: CGFloat,
+                formLineDashLengths: [CGFloat]?,
                 formColor: NSUIColor?)
     {
         self.label = label
         self.form = form
         self.formSize = formSize
         self.formLineWidth = formLineWidth
+        self.formLineDashPhase = formLineDashPhase
+        self.formLineDashLengths = formLineDashLengths
         self.formColor = formColor
     }
 
@@ -61,9 +67,25 @@ public class LegendEntry: NSObject
 
     /// Line width used for shapes that consist of lines.
     ///
-    /// Set as NaN to use the legend's default
+    /// Set to NaN to use the legend's default.
     public var formLineWidth: CGFloat = CGFloat.NaN
 
+    /// Line dash configuration for shapes that consist of lines.
+    ///
+    /// This is how much (in pixels) into the dash pattern are we starting from.
+    ///
+    /// Set to NaN to use the legend's default.
+    public var formLineDashPhase: CGFloat = 0.0
+
+    /// Line dash configuration for shapes that consist of lines.
+    ///
+    /// This is the actual dash pattern.
+    /// I.e. [2, 3] will paint [--   --   ]
+    /// [1, 3, 4, 2] will paint [-   ----  -   ----  ]
+    ///
+    /// Set to nil to use the legend's default.
+    public var formLineDashLengths: [CGFloat]?
+
     /// The color for drawing the form
     public var formColor: NSUIColor?
 }

Charts/Classes/Data/Implementations/ChartBaseDataSet.swift

@@ -327,6 +327,18 @@ public class ChartBaseDataSet: NSObject, IChartDataSet
     /// Return `NaN` to use the default legend form line width.
     public var formLineWidth: CGFloat = CGFloat.NaN
 
+    /// Line dash configuration for legend shapes that consist of lines.
+    ///
+    /// This is how much (in pixels) into the dash pattern are we starting from.
+    public var formLineDashPhase: CGFloat = 0.0
+
+    /// Line dash configuration for legend shapes that consist of lines.
+    ///
+    /// This is the actual dash pattern.
+    /// I.e. [2, 3] will paint [--   --   ]
+    /// [1, 3, 4, 2] will paint [-   ----  -   ----  ]
+    public var formLineDashLengths: [CGFloat]? = nil
+
     /// Set this to true to draw y-values on the chart
     public var drawValuesEnabled = true
 

Charts/Classes/Data/Interfaces/IChartDataSet.swift

@@ -200,6 +200,18 @@ public protocol IChartDataSet
     /// Return `NaN` to use the default legend form line width.
     var formLineWidth: CGFloat { get }
 
+    /// Line dash configuration for legend shapes that consist of lines.
+    ///
+    /// This is how much (in pixels) into the dash pattern are we starting from.
+    var formLineDashPhase: CGFloat { get }
+
+    /// Line dash configuration for legend shapes that consist of lines.
+    ///
+    /// This is the actual dash pattern.
+    /// I.e. [2, 3] will paint [--   --   ]
+    /// [1, 3, 4, 2] will paint [-   ----  -   ----  ]
+    var formLineDashLengths: [CGFloat]? { get }
+
     /// Set this to true to draw y-values on the chart
     var drawValuesEnabled: Bool { get set }
 

Charts/Classes/Renderers/LegendRenderer.swift

@@ -63,6 +63,8 @@ public class LegendRenderer: Renderer
                                 form: dataSet.form,
                                 formSize: dataSet.formSize,
                                 formLineWidth: dataSet.formLineWidth,
+                                formLineDashPhase: dataSet.formLineDashPhase,
+                                formLineDashLengths: dataSet.formLineDashLengths,
                                 formColor: clrs[j]
                             )
                         )
@@ -78,6 +80,8 @@ public class LegendRenderer: Renderer
                                 form: .None,
                                 formSize: CGFloat.NaN,
                                 formLineWidth: CGFloat.NaN,
+                                formLineDashPhase: 0.0,
+                                formLineDashLengths: nil,
                                 formColor: nil
                             )
                         )
@@ -95,6 +99,8 @@ public class LegendRenderer: Renderer
                                 form: dataSet.form,
                                 formSize: dataSet.formSize,
                                 formLineWidth: dataSet.formLineWidth,
+                                formLineDashPhase: dataSet.formLineDashPhase,
+                                formLineDashLengths: dataSet.formLineDashLengths,
                                 formColor: clrs[j]
                             )
                         )
@@ -110,6 +116,8 @@ public class LegendRenderer: Renderer
                                 form: .None,
                                 formSize: CGFloat.NaN,
                                 formLineWidth: CGFloat.NaN,
+                                formLineDashPhase: 0.0,
+                                formLineDashLengths: nil,
                                 formColor: nil
                             )
                         )
@@ -126,6 +134,8 @@ public class LegendRenderer: Renderer
                             form: dataSet.form,
                             formSize: dataSet.formSize,
                             formLineWidth: dataSet.formLineWidth,
+                            formLineDashPhase: dataSet.formLineDashPhase,
+                            formLineDashLengths: dataSet.formLineDashLengths,
                             formColor: candleDataSet.decreasingColor
                         )
                     )
@@ -136,6 +146,8 @@ public class LegendRenderer: Renderer
                             form: dataSet.form,
                             formSize: dataSet.formSize,
                             formLineWidth: dataSet.formLineWidth,
+                            formLineDashPhase: dataSet.formLineDashPhase,
+                            formLineDashLengths: dataSet.formLineDashLengths,
                             formColor: candleDataSet.increasingColor
                         )
                     )
@@ -163,6 +175,8 @@ public class LegendRenderer: Renderer
                                 form: dataSet.form,
                                 formSize: dataSet.formSize,
                                 formLineWidth: dataSet.formLineWidth,
+                                formLineDashPhase: dataSet.formLineDashPhase,
+                                formLineDashLengths: dataSet.formLineDashLengths,
                                 formColor: clrs[j]
                             )
                         )
@@ -522,8 +536,20 @@ public class LegendRenderer: Renderer
         case .Line:
 
             let formLineWidth = isnan(entry.formLineWidth) ? legend.formLineWidth : entry.formLineWidth
+            let formLineDashPhase = isnan(entry.formLineDashPhase) ? legend.formLineDashPhase : entry.formLineDashPhase
+            let formLineDashLengths = entry.formLineDashLengths == nil ? legend.formLineDashLengths : entry.formLineDashLengths
 
             CGContextSetLineWidth(context, formLineWidth)
+
+            if formLineDashLengths != nil && formLineDashLengths!.count > 0
+            {
+                CGContextSetLineDash(context, formLineDashPhase, formLineDashLengths!, formLineDashLengths!.count)
+            }
+            else
+            {
+                CGContextSetLineDash(context, 0.0, nil, 0)
+            }
+
             CGContextSetStrokeColorWithColor(context, formColor.CGColor)
 
             _formLineSegmentsBuffer[0].x = x

ChartsDemo/Classes/Demos/LineChart1ViewController.m

@@ -161,6 +161,9 @@ - (void)setDataCount:(int)count range:(double)range
         set1.circleRadius = 3.0;
         set1.drawCircleHoleEnabled = NO;
         set1.valueFont = [UIFont systemFontOfSize:9.f];
+        set1.formLineDashLengths = @[@5.f, @2.5f];
+        set1.formLineWidth = 1.0;
+        set1.formSize = 15.0;
 
         NSArray *gradientColors = @[
                                     (id)[ChartColorTemplates colorFromString:@"#00ff0000"].CGColor,