combined chart highlighter will return the dataSetIndex of the whole …

…data, not each sub data's index

add one more bar data set in demo view controller (+4 squashed commits)
Squashed commits:
[44ce60e] rename some BarChartDataProvider protocol methods not the same as ChartDataProvider
[1bd8c22] Fix issue #329 check _deltaX when only lineData exists
[90a327d] 1. fix bug in getDataSetIndex, it will detect what dataSet it is and determine how to proceed
2. I also override getMarkerPosition for CombinedChartView
[80aa1b3] add support for grouped bars in CombinedChartView.
add a new demo view controller called GroupedCombinedChartViewController, to illustrate multiple bars + multiple line

Charts/Charts.xcodeproj/project.pbxproj

@@ -370,6 +370,7 @@
 				5B0032441B6524AD00B6A2FE /* ChartHighlight.swift */,
 				5B0032461B6524D300B6A2FE /* ChartRange.swift */,
 				5B0032481B6525FC00B6A2FE /* ChartHighlighter.swift */,
+				13D38A551B709EB0009D4C4D /* CombinedChartHighlighter.swift */,
 				5B00324A1B652BF900B6A2FE /* BarChartHighlighter.swift */,
 				5BAAA8551BB08E1D00B20D4D /* CombinedHighlighter.swift */,
 				5B00324C1B65351C00B6A2FE /* HorizontalBarChartHighlighter.swift */,
@@ -756,6 +757,7 @@
 				5B680D231A9D17C30026A057 /* ChartYAxis.swift in Sources */,
 				5B6A54A91AA66BBA000F57C2 /* RadarChartView.swift in Sources */,
 				5B378F171AD500A4009414A4 /* ChartAnimationEasing.swift in Sources */,
+				13D38A561B709EB0009D4C4D /* CombinedChartHighlighter.swift in Sources */,
 				5B6A548F1AA66A7A000F57C2 /* HorizontalBarChartRenderer.swift in Sources */,
 				5B6A54741AA5DEDC000F57C2 /* ChartXAxisRenderer.swift in Sources */,
 				5BD4C57F1BCDBF6C00462351 /* CandleChartDataProvider.swift in Sources */,

Charts/Classes/Charts/BarChartView.swift

@@ -160,6 +160,21 @@ public class BarChartView: BarLineChartViewBase, BarChartDataProvider
 
     // MARK: - BarChartDataProbider
 
+    public func getBarChartTransformer(which: ChartYAxis.AxisDependency) -> ChartTransformer
+    {
+        return super.getTransformer(which)
+    }
+
+    public var barChartXMax: Double
+        {
+            return _chartXMax
+    }
+
+    public var barChartXMin: Double
+        {
+            return _chartXMin
+    }
+
     public var barData: BarChartData? { return _data as? BarChartData }
 
     /// - returns: true if drawing the highlighting arrow is enabled, false if not

Charts/Classes/Charts/CombinedChartView.swift

@@ -20,6 +20,16 @@ public class CombinedChartView: BarLineChartViewBase, LineChartDataProvider, Bar
     /// the fill-formatter used for determining the position of the fill-line
     internal var _fillFormatter: ChartFillFormatter!
 
+    internal var _barChartXMax = Double(0.0)
+    internal var _barChartXMin = Double(0.0)
+    internal var _barChartDeltaX = CGFloat(0.0)
+
+    internal var _barChartLeftYAxisRenderer: ChartYAxisRenderer!
+    internal var _barChartRightYAxisRenderer: ChartYAxisRenderer!
+
+    internal var _barChartLeftAxisTransformer: ChartTransformer!
+    internal var _barChartRightAxisTransformer: ChartTransformer!
+
     /// enum that allows to specify the order in which the different data objects for the combined-chart are drawn
     @objc
     public enum CombinedChartDrawOrder: Int
@@ -41,6 +51,12 @@ public class CombinedChartView: BarLineChartViewBase, LineChartDataProvider, Bar
         let workaroundFormatter = BarLineChartFillFormatter()
         _fillFormatter = workaroundFormatter
 
+        _barChartLeftAxisTransformer = ChartTransformer(viewPortHandler: _viewPortHandler)
+        _barChartRightAxisTransformer = ChartTransformer(viewPortHandler: _viewPortHandler)
+
+        _barChartLeftYAxisRenderer = ChartYAxisRenderer(viewPortHandler: _viewPortHandler, yAxis: _leftAxis, transformer: _leftAxisTransformer)
+        _barChartRightYAxisRenderer = ChartYAxisRenderer(viewPortHandler: _viewPortHandler, yAxis: _rightAxis, transformer: _rightAxisTransformer)
+
         renderer = CombinedChartRenderer(chart: self, animator: _animator, viewPortHandler: _viewPortHandler)
     }
 
@@ -71,6 +87,26 @@ public class CombinedChartView: BarLineChartViewBase, LineChartDataProvider, Bar
                     }
                 }
             }
+
+            if (self.barData !== nil)
+            {
+                let barData = self.barData
+
+                _barChartXMin = _chartXMin
+                _barChartXMax = _chartXMax
+                _barChartDeltaX = _deltaX
+                // increase deltax by 1 because the bars have a width of 1
+                _barChartDeltaX += 0.5
+
+                // extend xDelta to make space for multiple datasets (if ther are one)
+                _barChartDeltaX *= CGFloat(barData!.dataSetCount)
+
+                let maxEntry = _data.xValCount
+
+                let groupSpace = barData!.groupSpace
+                _barChartDeltaX += CGFloat(maxEntry) * groupSpace
+                _barChartXMax = Double(_barChartDeltaX) - _barChartXMin
+            }
         }
 
         _deltaX = CGFloat(abs(_chartXMax - _chartXMin))
@@ -81,6 +117,78 @@ public class CombinedChartView: BarLineChartViewBase, LineChartDataProvider, Bar
         }
     }
 
+    internal override func prepareValuePxMatrix()
+    {
+        super.prepareValuePxMatrix()
+
+        _barChartRightAxisTransformer.prepareMatrixValuePx(chartXMin: _barChartXMin, deltaX: _barChartDeltaX, deltaY: CGFloat(_rightAxis.axisRange), chartYMin: _rightAxis.axisMinimum)
+        _barChartLeftAxisTransformer.prepareMatrixValuePx(chartXMin: _barChartXMin, deltaX: _barChartDeltaX, deltaY: CGFloat(_leftAxis.axisRange), chartYMin: _leftAxis.axisMinimum)
+    }
+
+    internal override func prepareOffsetMatrix()
+    {
+        super.prepareOffsetMatrix()
+
+        _barChartRightAxisTransformer.prepareMatrixOffset(_rightAxis.isInverted)
+        _barChartLeftAxisTransformer.prepareMatrixOffset(_leftAxis.isInverted)
+    }
+
+    /// Returns the Transformer class that contains all matrices and is
+    /// responsible for transforming values into pixels on the screen and
+    /// backwards.
+    public func getBarChartTransformer(which: ChartYAxis.AxisDependency) -> ChartTransformer
+    {
+        if (which == .Left)
+        {
+            return _barChartLeftAxisTransformer
+        }
+        else
+        {
+            return _barChartRightAxisTransformer
+        }
+    }
+
+    public override func getMarkerPosition(entry e: ChartDataEntry, highlight: ChartHighlight) -> CGPoint
+    {
+        let dataSetIndex = highlight.dataSetIndex
+        let dataSet = _data.getDataSetByIndex(dataSetIndex)
+        var xPos = CGFloat(e.xIndex)
+        var yPos = e.value
+
+        if (dataSet.isKindOfClass(BarChartDataSet))
+        {
+            let bd = (_data as! CombinedChartData).barData
+            let space = bd.groupSpace
+
+            let barDataSetIndex = bd.indexOfDataSet(dataSet)
+
+            let x = CGFloat(e.xIndex * (bd.dataSetCount - 1) + barDataSetIndex) + space * CGFloat(e.xIndex) + space / 2.0
+
+            xPos += x
+
+            if let barEntry = e as? BarChartDataEntry
+            {
+                if barEntry.values != nil && highlight.range !== nil
+                {
+                    yPos = highlight.range!.to
+                }
+            }
+        }
+
+        var pt = CGPoint(x: xPos, y: CGFloat(yPos) * _animator.phaseY)
+
+        if (dataSet.isKindOfClass(BarChartDataSet))
+        {
+            getBarChartTransformer(_data.getDataSetByIndex(dataSetIndex)!.axisDependency).pointValueToPixel(&pt)
+        }
+        else
+        {
+            getTransformer(_data.getDataSetByIndex(dataSetIndex)!.axisDependency).pointValueToPixel(&pt)
+        }
+
+        return pt
+    }
+
     public override var data: ChartData?
     {
         get
@@ -138,6 +246,16 @@ public class CombinedChartView: BarLineChartViewBase, LineChartDataProvider, Bar
         }
     }
 
+    public var barChartXMax: Double
+        {
+            return _barChartXMax
+    }
+
+    public var barChartXMin: Double
+        {
+            return _barChartXMin
+    }
+
     // MARK: - ScatterChartDataProvider
 
     public var scatterData: ScatterChartData?