View port handler nonnil (#2980)

* `ViewPortHandler` is now non-optional in all, if not most cases

* Removed unnecessary `init()`s from `ViewPortHandler` and related

* `Renderer` now has a constant `ViewPortHandler`

* Pulled latest master

* Fixes for PR review

Removed extraneous comment
Removed extra whitespace

* Removed extra new lines

Source/Charts/Charts/ChartViewBase.swift

@@ -221,8 +221,7 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
         _animator = Animator()
         _animator.delegate = self
 
-        _viewPortHandler = ViewPortHandler()
-        _viewPortHandler.setChartDimens(width: bounds.size.width, height: bounds.size.height)
+        _viewPortHandler = ViewPortHandler(width: bounds.size.width, height: bounds.size.height)
 
         chartDescription = Description()
 

Source/Charts/Renderers/AxisRendererBase.swift

@@ -20,13 +20,8 @@ open class AxisRendererBase: Renderer
 
     /// transformer to transform values to screen pixels and return
     @objc open var transformer: Transformer?
-
-    public override init()
-    {
-        super.init()
-    }
-
-    @objc public init(viewPortHandler: ViewPortHandler?, transformer: Transformer?, axis: AxisBase?)
+
+    @objc public init(viewPortHandler: ViewPortHandler, transformer: Transformer?, axis: AxisBase?)
     {
         super.init(viewPortHandler: viewPortHandler)
 
@@ -68,23 +63,20 @@ open class AxisRendererBase: Renderer
         if let transformer = self.transformer
         {
             // calculate the starting and entry point of the y-labels (depending on zoom / contentrect bounds)
-            if let viewPortHandler = viewPortHandler
+            if viewPortHandler.contentWidth > 10.0 && !viewPortHandler.isFullyZoomedOutY
             {
-                if viewPortHandler.contentWidth > 10.0 && !viewPortHandler.isFullyZoomedOutY
+                let p1 = transformer.valueForTouchPoint(CGPoint(x: viewPortHandler.contentLeft, y: viewPortHandler.contentTop))
+                let p2 = transformer.valueForTouchPoint(CGPoint(x: viewPortHandler.contentLeft, y: viewPortHandler.contentBottom))
+
+                if !inverted
+                {
+                    min = Double(p2.y)
+                    max = Double(p1.y)
+                }
+                else
                 {
-                    let p1 = transformer.valueForTouchPoint(CGPoint(x: viewPortHandler.contentLeft, y: viewPortHandler.contentTop))
-                    let p2 = transformer.valueForTouchPoint(CGPoint(x: viewPortHandler.contentLeft, y: viewPortHandler.contentBottom))
-
-                    if !inverted
-                    {
-                        min = Double(p2.y)
-                        max = Double(p1.y)
-                    }
-                    else
-                    {
-                        min = Double(p1.y)
-                        max = Double(p2.y)
-                    }
+                    min = Double(p1.y)
+                    max = Double(p2.y)
                 }
             }
         }

Source/Charts/Renderers/BarChartRenderer.swift

@@ -25,7 +25,7 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
 
     @objc open weak var dataProvider: BarChartDataProvider?
 
-    @objc public init(dataProvider: BarChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(dataProvider: BarChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
 
@@ -207,10 +207,7 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
 
     @objc open func drawDataSet(context: CGContext, dataSet: IBarChartDataSet, index: Int)
     {
-        guard
-            let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let dataProvider = dataProvider else { return }
 
         let trans = dataProvider.getTransformer(forAxis: dataSet.axisDependency)
 
@@ -226,9 +223,7 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
         // draw the bar shadow before the values
         if dataProvider.isDrawBarShadowEnabled
         {
-            guard
-                let barData = dataProvider.barData
-                else { return }
+            guard let barData = dataProvider.barData else { return }
 
             let barWidth = barData.barWidth
             let barWidthHalf = barWidth / 2.0
@@ -355,17 +350,16 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
         {
             guard
                 let dataProvider = dataProvider,
-                let viewPortHandler = self.viewPortHandler,
                 let barData = dataProvider.barData
                 else { return }
-            
+
             var dataSets = barData.dataSets
 
             let valueOffsetPlus: CGFloat = 4.5
             var posOffset: CGFloat
             var negOffset: CGFloat
             let drawValueAboveBar = dataProvider.isDrawValueAboveBarEnabled
-            
+
             for dataSetIndex in 0 ..< barData.dataSetCount
             {
                 guard let dataSet = dataSets[dataSetIndex] as? IBarChartDataSet else { continue }

Source/Charts/Renderers/BarLineScatterCandleBubbleRenderer.swift

@@ -17,7 +17,7 @@ open class BarLineScatterCandleBubbleRenderer: DataRenderer
 {
     internal var _xBounds = XBounds() // Reusable XBounds object
 
-    public override init(animator: Animator, viewPortHandler: ViewPortHandler?)
+    public override init(animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
     }

Source/Charts/Renderers/BubbleChartRenderer.swift

@@ -21,7 +21,7 @@ open class BubbleChartRenderer: BarLineScatterCandleBubbleRenderer
 {
     @objc open weak var dataProvider: BubbleChartDataProvider?
 
-    @objc public init(dataProvider: BubbleChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(dataProvider: BubbleChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
 
@@ -59,10 +59,7 @@ open class BubbleChartRenderer: BarLineScatterCandleBubbleRenderer
 
     @objc open func drawDataSet(context: CGContext, dataSet: IBubbleChartDataSet)
     {
-        guard
-            let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let dataProvider = dataProvider else { return }
 
         let trans = dataProvider.getTransformer(forAxis: dataSet.axisDependency)
 
@@ -124,9 +121,8 @@ open class BubbleChartRenderer: BarLineScatterCandleBubbleRenderer
 
     open override func drawValues(context: CGContext)
     {
-        guard
-            let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler,
+        guard let
+            dataProvider = dataProvider,
             let bubbleData = dataProvider.bubbleData,
             isDrawingValuesAllowed(dataProvider: dataProvider),
             let dataSets = bubbleData.dataSets as? [IBubbleChartDataSet]
@@ -215,10 +211,9 @@ open class BubbleChartRenderer: BarLineScatterCandleBubbleRenderer
     {
         guard
             let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler,
             let bubbleData = dataProvider.bubbleData
             else { return }
-        
+
         context.saveGState()
         defer { context.restoreGState() }
 

Source/Charts/Renderers/CandleStickChartRenderer.swift

@@ -21,7 +21,7 @@ open class CandleStickChartRenderer: LineScatterCandleRadarRenderer
 {
     @objc open weak var dataProvider: CandleChartDataProvider?
 
-    @objc public init(dataProvider: CandleChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(dataProvider: CandleChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
 
@@ -236,7 +236,6 @@ open class CandleStickChartRenderer: LineScatterCandleRadarRenderer
     {
         guard
             let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler,
             let candleData = dataProvider.candleData
             else { return }
 

Source/Charts/Renderers/ChartDataRendererBase.swift

@@ -17,7 +17,7 @@ open class DataRenderer: Renderer
 {
     @objc open let animator: Animator
 
-    @objc public init(animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(animator: Animator, viewPortHandler: ViewPortHandler)
     {
         self.animator = animator
 
@@ -53,8 +53,7 @@ open class DataRenderer: Renderer
 
     @objc open func isDrawingValuesAllowed(dataProvider: ChartDataProvider?) -> Bool
     {
-        guard let data = dataProvider?.data
-            else { return false }
-        return data.entryCount < Int(CGFloat(dataProvider?.maxVisibleCount ?? 0) * (self.viewPortHandler?.scaleX ?? 1.0))
+        guard let data = dataProvider?.data else { return false }
+        return data.entryCount < Int(CGFloat(dataProvider?.maxVisibleCount ?? 0) * viewPortHandler.scaleX)
     }
 }

Source/Charts/Renderers/CombinedChartRenderer.swift

@@ -26,7 +26,7 @@ open class CombinedChartRenderer: DataRenderer
 
     internal var _drawOrder: [CombinedChartView.DrawOrder] = [.bar, .bubble, .line, .candle, .scatter]
 
-    @objc public init(chart: CombinedChartView?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(chart: CombinedChartView?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
 
@@ -40,10 +40,7 @@ open class CombinedChartRenderer: DataRenderer
     {
         _renderers = [DataRenderer]()
 
-        guard let
-            chart = chart,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let chart = chart else { return }
 
         for order in drawOrder
         {

Source/Charts/Renderers/HorizontalBarChartRenderer.swift

@@ -24,7 +24,7 @@ open class HorizontalBarChartRenderer: BarChartRenderer
         var rects = [CGRect]()
     }
 
-    public override init(dataProvider: BarChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    public override init(dataProvider: BarChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(dataProvider: dataProvider, animator: animator, viewPortHandler: viewPortHandler)
     }
@@ -181,10 +181,7 @@ open class HorizontalBarChartRenderer: BarChartRenderer
 
     open override func drawDataSet(context: CGContext, dataSet: IBarChartDataSet, index: Int)
     {
-        guard let
-            dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let dataProvider = dataProvider else { return }
 
         let trans = dataProvider.getTransformer(forAxis: dataSet.axisDependency)
 
@@ -305,8 +302,7 @@ open class HorizontalBarChartRenderer: BarChartRenderer
         {
             guard
                 let dataProvider = dataProvider,
-                let barData = dataProvider.barData,
-                let viewPortHandler = self.viewPortHandler
+                let barData = dataProvider.barData
                 else { return }
 
             var dataSets = barData.dataSets
@@ -605,7 +601,7 @@ open class HorizontalBarChartRenderer: BarChartRenderer
     {
         guard let data = dataProvider?.data
             else { return false }
-        return data.entryCount < Int(CGFloat(dataProvider?.maxVisibleCount ?? 0) * (self.viewPortHandler?.scaleY ?? 1.0))
+        return data.entryCount < Int(CGFloat(dataProvider?.maxVisibleCount ?? 0) * self.viewPortHandler.scaleY)
     }
 
     /// Sets the drawing position of the highlight object based on the riven bar-rect.

Source/Charts/Renderers/LegendRenderer.swift

@@ -22,7 +22,7 @@ open class LegendRenderer: Renderer
     /// the legend object this renderer renders
     @objc open var legend: Legend?
 
-    @objc public init(viewPortHandler: ViewPortHandler?, legend: Legend?)
+    @objc public init(viewPortHandler: ViewPortHandler, legend: Legend?)
     {
         super.init(viewPortHandler: viewPortHandler)
 
@@ -32,10 +32,7 @@ open class LegendRenderer: Renderer
     /// Prepares the legend and calculates all needed forms, labels and colors.
     @objc open func computeLegend(data: ChartData)
     {
-        guard
-            let legend = legend,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let legend = legend else { return }
 
         if !legend.isLegendCustom
         {
@@ -194,10 +191,7 @@ open class LegendRenderer: Renderer
 
     @objc open func renderLegend(context: CGContext)
     {
-        guard
-            let legend = legend,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let legend = legend else { return }
 
         if !legend.enabled
         {

Source/Charts/Renderers/LineChartRenderer.swift

@@ -21,7 +21,7 @@ open class LineChartRenderer: LineRadarRenderer
 {
     @objc open weak var dataProvider: LineChartDataProvider?
 
-    @objc public init(dataProvider: LineChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler?)
+    @objc public init(dataProvider: LineChartDataProvider?, animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
 
@@ -286,10 +286,7 @@ open class LineChartRenderer: LineRadarRenderer
 
     @objc open func drawLinear(context: CGContext, dataSet: ILineChartDataSet)
     {
-        guard
-            let dataProvider = dataProvider,
-            let viewPortHandler = self.viewPortHandler
-            else { return }
+        guard let dataProvider = dataProvider else { return }
 
         let trans = dataProvider.getTransformer(forAxis: dataSet.axisDependency)
 
@@ -502,10 +499,9 @@ open class LineChartRenderer: LineRadarRenderer
     {
         guard
             let dataProvider = dataProvider,
-            let lineData = dataProvider.lineData,
-            let viewPortHandler = self.viewPortHandler
+            let lineData = dataProvider.lineData
             else { return }
-        
+
         if isDrawingValuesAllowed(dataProvider: dataProvider)
         {
             var dataSets = lineData.dataSets
@@ -597,12 +593,11 @@ open class LineChartRenderer: LineRadarRenderer
     {
         guard
             let dataProvider = dataProvider,
-            let lineData = dataProvider.lineData,
-            let viewPortHandler = self.viewPortHandler
+            let lineData = dataProvider.lineData
             else { return }
 
         let phaseY = animator.phaseY
-        
+
         let dataSets = lineData.dataSets
 
         var pt = CGPoint()

Source/Charts/Renderers/LineRadarRenderer.swift

@@ -15,16 +15,14 @@ import CoreGraphics
 @objc(LineRadarChartRenderer)
 open class LineRadarRenderer: LineScatterCandleRadarRenderer
 {
-    public override init(animator: Animator, viewPortHandler: ViewPortHandler?)
+    public override init(animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
     }
 
     /// Draws the provided path in filled mode with the provided drawable.
     @objc open func drawFilledPath(context: CGContext, path: CGPath, fill: Fill, fillAlpha: CGFloat)
     {
-        guard let viewPortHandler = self.viewPortHandler
-            else { return }
 
         context.saveGState()
         context.beginPath()

Source/Charts/Renderers/LineScatterCandleRadarRenderer.swift

@@ -15,7 +15,7 @@ import CoreGraphics
 @objc(LineScatterCandleRadarChartRenderer)
 open class LineScatterCandleRadarRenderer: BarLineScatterCandleBubbleRenderer
 {
-    public override init(animator: Animator, viewPortHandler: ViewPortHandler?)
+    public override init(animator: Animator, viewPortHandler: ViewPortHandler)
     {
         super.init(animator: animator, viewPortHandler: viewPortHandler)
     }
@@ -27,9 +27,6 @@ open class LineScatterCandleRadarRenderer: BarLineScatterCandleBubbleRenderer
     /// :param: vertical
     @objc open func drawHighlightLines(context: CGContext, point: CGPoint, set: ILineScatterCandleRadarChartDataSet)
     {
-        guard let
-            viewPortHandler = self.viewPortHandler
-            else { return }
 
         // draw vertical highlight lines
         if set.isVerticalHighlightIndicatorEnabled