Chartdata collection conformance (#3023)

* Added Collection conformances

MutableCollection
RandomAccessCollection
RangeReplaceableCollection

* Fixed required initializers

* ChartData adopts ExressibleByArrayLiteral

* Updates for PR

Also added remove subrange.

* PR review fixes

* Removed unnecessary `get` from subscripts.

* Disabled `remove(at:)` for CombinedChartView

* Relocated `appendEntry(_:todataSet:)`

* Removed methods from CombinedChartData

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

@@ -14,7 +14,7 @@ import CoreGraphics
 
 open class BarChartData: BarLineScatterCandleBubbleChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -23,7 +23,12 @@ open class BarChartData: BarLineScatterCandleBubbleChartData
     {
         super.init(dataSets: dataSets)
     }
-
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
+
     /// The width of the bars on the x-axis, in values (not pixels)
     ///
     /// **default**: 0.85

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

@@ -13,7 +13,7 @@ import Foundation
 
 open class BarLineScatterCandleBubbleChartData: ChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -22,4 +22,9 @@ open class BarLineScatterCandleBubbleChartData: ChartData
     {
         super.init(dataSets: dataSets)
     }
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
 }

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

@@ -14,7 +14,7 @@ import CoreGraphics
 
 open class BubbleChartData: BarLineScatterCandleBubbleChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -23,7 +23,12 @@ open class BubbleChartData: BarLineScatterCandleBubbleChartData
     {
         super.init(dataSets: dataSets)
     }
-
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
+
     /// Sets the width of the circle that surrounds the bubble when highlighted for all DataSet objects this data object contains
     @objc open func setHighlightCircleWidth(_ width: CGFloat)
     {

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

@@ -13,7 +13,7 @@ import Foundation
 
 open class CandleChartData: BarLineScatterCandleBubbleChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -22,4 +22,9 @@ open class CandleChartData: BarLineScatterCandleBubbleChartData
     {
         super.init(dataSets: dataSets)
     }
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
 }

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

@@ -11,7 +11,7 @@
 
 import Foundation
 
-open class ChartData: NSObject
+open class ChartData: NSObject, ExpressibleByArrayLiteral
 {
     internal var _yMax: Double = -Double.greatestFiniteMagnitude
     internal var _yMin: Double = Double.greatestFiniteMagnitude
@@ -24,13 +24,20 @@ open class ChartData: NSObject
 
     internal var _dataSets = [ChartDataSetProtocol]()
 
-    public override init()
+    public override required init()
     {
         super.init()
-
-        _dataSets = [ChartDataSetProtocol]()
     }
-
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init()
+
+        _dataSets = elements
+
+        self.initialize(dataSets: _dataSets)
+    }
+
     @objc public init(dataSets: [ChartDataSetProtocol]?)
     {
         super.init()
@@ -491,22 +498,20 @@ open class ChartData: NSObject
     }
 
     /// Adds an Entry to the DataSet at the specified index. Entries are added to the end of the list.
-    @objc open func addEntry(_ e: ChartDataEntry, dataSetIndex: Int)
+    @objc(addEntry:dataSetIndex:)
+    open func appendEntry(_ e: ChartDataEntry, toDataSet dataSetIndex: Index)
     {
-        if _dataSets.count > dataSetIndex && dataSetIndex >= 0
-        {
-            let set = _dataSets[dataSetIndex]
-
-            if !set.addEntry(e) { return }
-
-            calcMinMax(entry: e, axis: set.axisDependency)
-        }
-        else
+        guard indices.contains(dataSetIndex) else
         {
             print("ChartData.addEntry() - Cannot add Entry because dataSetIndex too high or too low.", terminator: "\n")
+            return
         }
+
+        let set = self[dataSetIndex]
+        if !set.addEntry(e) { return }
+        calcMinMax(entry: e, axis: set.axisDependency)
     }
-    
+
     /// Removes the given Entry object from the DataSet at the specified index.
     @objc @discardableResult open func removeEntry(_ entry: ChartDataEntry, dataSetIndex: Int) -> Bool
     {
@@ -757,3 +762,165 @@ open class ChartData: NSObject
         return max
     }
 }
+
+// MARK: MutableCollection
+extension ChartData: MutableCollection
+{
+    public typealias Index = Int
+    public typealias Element = ChartDataSetProtocol
+
+    public var startIndex: Index
+    {
+        return _dataSets.startIndex
+    }
+
+    public var endIndex: Index
+    {
+        return _dataSets.endIndex
+    }
+
+    public func index(after: Index) -> Index
+    {
+        return _dataSets.index(after: after)
+    }
+
+    public subscript(position: Index) -> Element
+    {
+        get{ return _dataSets[position] }
+        set{ self._dataSets[position] = newValue }
+    }
+}
+
+// MARK: RandomAccessCollection
+extension ChartData: RandomAccessCollection
+{
+    public func index(before: Index) -> Index
+    {
+        return _dataSets.index(before: before)
+    }
+}
+
+// MARK: RangeReplaceableCollection
+extension ChartData: RangeReplaceableCollection
+{
+    public func append(_ newElement: Element)
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("append(_:) not supported for CombinedData")
+        }
+
+        _dataSets.append(newElement)
+        calcMinMax(dataSet: newElement)
+    }
+
+    public func remove(at position: Index) -> Element
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("remove(at:) not supported for CombinedData")
+        }
+
+        let element = _dataSets.remove(at: position)
+        calcMinMax()
+        return element
+    }
+
+    public func removeFirst() -> Element
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeFirst() not supported for CombinedData")
+        }
+
+        let element = _dataSets.removeFirst()
+        notifyDataChanged()
+        return element
+    }
+
+    public func removeFirst(_ n: Int)
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeFirst(_:) not supported for CombinedData")
+        }
+
+        _dataSets.removeFirst(n)
+        notifyDataChanged()
+    }
+
+    public func removeLast() -> Element
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeLast() not supported for CombinedData")
+        }
+
+        let element = _dataSets.removeLast()
+        notifyDataChanged()
+        return element
+    }
+
+    public func removeLast(_ n: Int)
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeLast(_:) not supported for CombinedData")
+        }
+
+        _dataSets.removeLast(n)
+        notifyDataChanged()
+    }
+
+    public func removeSubrange<R>(_ bounds: R) where R : RangeExpression, ChartData.Index == R.Bound
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeSubrange<R>(_:) not supported for CombinedData")
+        }
+
+        _dataSets.removeSubrange(bounds)
+        notifyDataChanged()
+    }
+
+    public func removeAll(keepingCapacity keepCapacity: Bool)
+    {
+        guard !(self is CombinedChartData) else
+        {
+            fatalError("removeAll(keepingCapacity:) not supported for CombinedData")
+        }
+
+        _dataSets.removeAll(keepingCapacity: keepCapacity)
+        notifyDataChanged()
+    }
+}
+
+// MARK: Swift Accessors
+extension ChartData
+{
+    /// Retrieve the index of a ChartDataSet with a specific label from the ChartData. Search can be case sensitive or not.
+    /// **IMPORTANT: This method does calculations at runtime, do not over-use in performance critical situations.**
+    ///
+    /// - Parameters:
+    ///   - label: The label to search for
+    ///   - ignoreCase: if true, the search is not case-sensitive
+    /// - Returns: The index of the DataSet Object with the given label. `nil` if not found
+    public func index(forLabel label: String, ignoreCase: Bool) -> Index?
+    {
+        return ignoreCase
+            ? index { $0.label?.caseInsensitiveCompare(label) == .orderedSame }
+            : index { $0.label == label }
+    }
+
+    public subscript(label: String, ignoreCase: Bool) -> Element?
+    {
+        guard let index = index(forLabel: label, ignoreCase: ignoreCase) else { return nil }
+        return self[index]
+    }
+
+    public subscript(entry: ChartDataEntry) -> Element?
+    {
+        guard let index = index(where: { $0.entryForXValue(entry.x, closestToY: entry.y) === entry }) else { return nil }
+        return self[index]
+    }
+}

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

@@ -19,7 +19,7 @@ open class CombinedChartData: BarLineScatterCandleBubbleChartData
     private var _candleData: CandleChartData!
     private var _bubbleData: BubbleChartData!
 
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -28,6 +28,11 @@ open class CombinedChartData: BarLineScatterCandleBubbleChartData
     {
         super.init(dataSets: dataSets)
     }
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
 
     @objc open var lineData: LineChartData!
     {

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

@@ -14,7 +14,7 @@ import Foundation
 /// Data object that encapsulates all data associated with a LineChart.
 open class LineChartData: ChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -23,4 +23,9 @@ open class LineChartData: ChartData
     {
         super.init(dataSets: dataSets)
     }
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
 }

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

@@ -13,7 +13,7 @@ import Foundation
 
 open class PieChartData: ChartData
 {
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -23,6 +23,11 @@ open class PieChartData: ChartData
         super.init(dataSets: dataSets)
     }
 
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
+
     @objc var dataSet: PieChartDataSetProtocol?
     {
         get

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

@@ -29,7 +29,7 @@ open class RadarChartData: ChartData
         self.labels = labels
     }
 
-    public override init()
+    public required init()
     {
         super.init()
     }
@@ -38,7 +38,12 @@ open class RadarChartData: ChartData
     {
         super.init(dataSets: dataSets)
     }
-
+
+    public required init(arrayLiteral elements: ChartDataSetProtocol...)
+    {
+        super.init(dataSets: elements)
+    }
+
     open override func entryForHighlight(_ highlight: Highlight) -> ChartDataEntry?
     {
         return getDataSetByIndex(highlight.dataSetIndex)?.entryForIndex(Int(highlight.x))