autoScaleMinMax is working again (Fixes #1209)

Charts/Classes/Charts/BarChartView.swift

@@ -35,11 +35,6 @@ public class BarChartView: BarLineChartViewBase, BarChartDataProvider
         guard let data = self.data as? BarChartData
             else { return }
 
-        if self.autoScaleMinMaxEnabled
-        {
-            data.calcMinMax()
-        }
-
         if fitBars
         {
             _xAxis.calculate(

Charts/Classes/Charts/BarLineChartViewBase.swift

@@ -25,8 +25,6 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
 
     /// flag that indicates if auto scaling on the y axis is enabled
     private var _autoScaleMinMaxEnabled = false
-    private var _autoScaleLastLowestVisibleX: Double?
-    private var _autoScaleLastHighestVisibleX: Double?
 
     private var _pinchZoomEnabled = false
     private var _doubleTapToZoomEnabled = true
@@ -189,20 +187,9 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
         _leftYAxisRenderer?.renderAxisLine(context: context)
         _rightYAxisRenderer?.renderAxisLine(context: context)
 
-        if (_autoScaleMinMaxEnabled)
+        if _autoScaleMinMaxEnabled
         {
-            let lowestVisibleX = self.lowestVisibleX,
-                highestVisibleX = self.highestVisibleX
-
-            if (_autoScaleLastLowestVisibleX == nil || _autoScaleLastLowestVisibleX != lowestVisibleX ||
-                _autoScaleLastHighestVisibleX == nil || _autoScaleLastHighestVisibleX != highestVisibleX)
-            {
-                calcMinMax()
-                calculateOffsets()
-
-                _autoScaleLastLowestVisibleX = lowestVisibleX
-                _autoScaleLastHighestVisibleX = highestVisibleX
-            }
+            autoScale()
         }
 
         // The renderers are responsible for clipping, to account for line-width center etc.
@@ -264,6 +251,26 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
         drawDescription(context: context)
     }
 
+    private var _autoScaleLastLowestVisibleX: Double?
+    private var _autoScaleLastHighestVisibleX: Double?
+
+    /// Performs auto scaling of the axis by recalculating the minimum and maximum y-values based on the entries currently in view.
+    internal func autoScale()
+    {
+        guard let data = _data
+            else { return }
+
+        data.calcMinMaxY(fromX: self.lowestVisibleX, toX: self.highestVisibleX)
+
+        _xAxis.calculate(min: data.xMin, max: data.xMax)
+
+        // calculate axis range (min / max) according to provided data
+        _leftAxis.calculate(min: data.getYMin(.Left), max: data.getYMax(.Left))
+        _rightAxis.calculate(min: data.getYMin(.Right), max: data.getYMax(.Right))
+
+        calculateOffsets();
+    }
+
     internal func prepareValuePxMatrix()
     {
         _rightAxisTransformer.prepareMatrixValuePx(chartXMin: _xAxis._axisMinimum, deltaX: CGFloat(xAxis.axisRange), deltaY: CGFloat(_rightAxis.axisRange), chartYMin: _rightAxis._axisMinimum)
@@ -305,11 +312,6 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
 
     internal override func calcMinMax()
     {
-        if _autoScaleMinMaxEnabled
-        {
-            _data?.calcMinMax()
-        }
-
         // calculate / set x-axis range
         _xAxis.calculate(min: _data?.xMin ?? 0.0, max: _data?.xMax ?? 0.0)
 

Charts/Classes/Data/Implementations/ChartBaseDataSet.swift

@@ -48,6 +48,11 @@ public class ChartBaseDataSet: NSObject, IChartDataSet
         fatalError("calcMinMax is not implemented in ChartBaseDataSet")
     }
 
+    public func calcMinMaxY(fromX fromX: Double, toX: Double)
+    {
+        fatalError("calcMinMaxY(fromX:, toX:) is not implemented in ChartBaseDataSet")
+    }
+
     public var yMin: Double
     {
         fatalError("yMin is not implemented in ChartBaseDataSet")

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

@@ -80,57 +80,39 @@ public class BarChartDataSet: BarLineScatterCandleBubbleChartDataSet, IBarChartD
         }
     }
 
-    public override func calcMinMax()
+    public override func calcMinMax(entry e: ChartDataEntry)
     {
-        if _values.count == 0
-        {
-            return
-        }
-
-        _yMax = -DBL_MAX
-        _yMin = DBL_MAX
-        _xMax = -DBL_MAX
-        _xMin = DBL_MAX
+        guard let e = e as? BarChartDataEntry
+            else { return }
 
-        for e in _values as! [BarChartDataEntry]
+        if !e.y.isNaN
         {
-            if !e.y.isNaN
+            if e.yValues == nil
             {
-                if e.yValues == nil
+                if e.y < _yMin
                 {
-                    if e.y < _yMin
-                    {
-                        _yMin = e.y
-                    }
-
-                    if e.y > _yMax
-                    {
-                        _yMax = e.y
-                    }
+                    _yMin = e.y
                 }
-                else
+
+                if e.y > _yMax
                 {
-                    if -e.negativeSum < _yMin
-                    {
-                        _yMin = -e.negativeSum
-                    }
-
-                    if e.positiveSum > _yMax
-                    {
-                        _yMax = e.positiveSum
-                    }
+                    _yMax = e.y
                 }
-
-                if e.x < _xMin
+            }
+            else
+            {
+                if -e.negativeSum < _yMin
                 {
-                    _xMin = e.x
+                    _yMin = -e.negativeSum
                 }
 
-                if e.x > _xMax
+                if e.positiveSum > _yMax
                 {
-                    _xMax = e.x
+                    _yMax = e.positiveSum
                 }
             }
+
+            calcMinMaxX(entry: e)
         }
     }
 

Charts/Classes/Data/Implementations/Standard/BubbleChartDataSet.swift

@@ -23,30 +23,18 @@ public class BubbleChartDataSet: BarLineScatterCandleBubbleChartDataSet, IBubble
     public var normalizeSizeEnabled: Bool = true
     public var isNormalizeSizeEnabled: Bool { return normalizeSizeEnabled }
 
-    public override func calcMinMax()
+    public override func calcMinMax(entry e: ChartDataEntry)
     {
-        if self.entryCount == 0
-        {
-            return
-        }
-
-        // need chart width to guess this properly
+        guard let e = e as? BubbleChartDataEntry
+            else { return }
+
+        super.calcMinMax(entry: e)
 
-        _yMax = -DBL_MAX
-        _yMin = DBL_MAX
-        _xMax = -DBL_MAX
-        _xMin = DBL_MAX
+        let size = e.size
 
-        for e in values as! [BubbleChartDataEntry]
+        if size > _maxSize
         {
-            calcMinMax(entry: e)
-
-            let size = e.size
-
-            if size > _maxSize
-            {
-                _maxSize = size
-            }
+            _maxSize = size
         }
     }
 

Charts/Classes/Data/Implementations/Standard/CandleChartDataSet.swift

@@ -28,42 +28,22 @@ public class CandleChartDataSet: LineScatterCandleRadarChartDataSet, ICandleChar
 
     // MARK: - Data functions and accessors
 
-    public override func calcMinMax()
+    public override func calcMinMax(entry e: ChartDataEntry)
     {
-        let yValCount = self.entryCount
+        guard let e = e as? CandleChartDataEntry
+            else { return }
 
-        if yValCount == 0
+        if (e.low < _yMin)
         {
-            return
+            _yMin = e.low
         }
 
-        _yMax = -DBL_MAX
-        _yMin = DBL_MAX
-        _xMax = -DBL_MAX
-        _xMin = DBL_MAX
-
-        for e in _values as! [CandleChartDataEntry]
+        if (e.high > _yMax)
         {
-            if (e.low < _yMin)
-            {
-                _yMin = e.low
-            }
-
-            if (e.high > _yMax)
-            {
-                _yMax = e.high
-            }
-
-            if (e.x < _xMin)
-            {
-                _xMin = e.x
-            }
-
-            if (e.x > _xMax)
-            {
-                _xMax = e.x
-            }
+            _yMax = e.high
         }
+
+        calcMinMaxX(entry: e)
     }
 
     // MARK: - Styling functions and accessors

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

@@ -47,14 +47,25 @@ public class ChartData: NSObject
 
     internal func initialize(dataSets: [IChartDataSet])
     {
-        calcMinMax()
+        notifyDataChanged()
     }
 
     /// Call this method to let the ChartData know that the underlying data has changed.
     /// Calling this performs all necessary recalculations needed when the contained data has changed.
     public func notifyDataChanged()
     {
-        initialize(_dataSets)
+        calcMinMax()
+    }
+
+    public func calcMinMaxY(fromX fromX: Double, toX: Double)
+    {
+        for set in _dataSets
+        {
+            set.calcMinMaxY(fromX: fromX, toX: toX)
+        }
+
+        // apply the new data
+        calcMinMax()
     }
 
     /// calc minimum and maximum y value over all datasets
@@ -126,6 +137,7 @@ public class ChartData: NSObject
         }
     }
 
+    /// Adjusts the current minimum and maximum values based on the provided Entry object.
     public func calcMinMax(entry e: ChartDataEntry, axis: YAxis.AxisDependency)
     {
         if _yMax < e.y
@@ -174,6 +186,7 @@ public class ChartData: NSObject
         }
     }
 
+    /// Adjusts the minimum and maximum values based on the given DataSet.
     public func calcMinMax(dataSet d: IChartDataSet)
     {
         if _yMax < d.yMax
@@ -325,7 +338,7 @@ public class ChartData: NSObject
         set
         {
             _dataSets = newValue
-            initialize(_dataSets)
+            notifyDataChanged()
         }
     }
 

Charts/Classes/Data/Implementations/Standard/ChartDataSet.swift

@@ -109,19 +109,30 @@ public class ChartDataSet: ChartBaseDataSet
         }
     }
 
-    /// Updates the min and max x and y value of this DataSet based on the given Entry.
-    ///
-    /// - parameter e:
-    internal func calcMinMax(entry e: ChartDataEntry)
+    public override func calcMinMaxY(fromX fromX: Double, toX: Double)
     {
-        if e.y < _yMin
+        if _values.count == 0
         {
-            _yMin = e.y
+            return
         }
-        if e.y > _yMax
+
+        _yMax = -DBL_MAX
+        _yMin = DBL_MAX
+
+        let indexFrom = entryIndex(x: fromX, rounding: .Down)
+        let indexTo = entryIndex(x: toX, rounding: .Up)
+
+        if indexTo <= indexFrom { return }
+
+        for i in indexFrom..<indexTo
         {
-            _yMax = e.y
+            // only recalculate y
+            calcMinMaxY(entry: _values[i])
         }
+    }
+
+    public func calcMinMaxX(entry e: ChartDataEntry)
+    {
         if e.x < _xMin
         {
             _xMin = e.x
@@ -132,6 +143,27 @@ public class ChartDataSet: ChartBaseDataSet
         }
     }
 
+    internal func calcMinMaxY(entry e: ChartDataEntry)
+    {
+        if e.y < _yMin
+        {
+            _yMin = e.y
+        }
+        if e.y > _yMax
+        {
+            _yMax = e.y
+        }
+    }
+
+    /// Updates the min and max x and y value of this DataSet based on the given Entry.
+    ///
+    /// - parameter e:
+    internal func calcMinMax(entry e: ChartDataEntry)
+    {
+        calcMinMaxX(entry: e)
+        calcMinMaxY(entry: e)
+    }
+
     /// - returns: The minimum y-value this DataSet holds
     public override var yMin: Double { return _yMin }