Add half line width to clipping rect of grid/limit lines (Fixes #1204)

ChartsOrg · Aug 14, 2016 · c05fbd8 · c05fbd8
1 parent a8cf54a
commit c05fbd8
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Showing 6 changed files with 71 additions and 27 deletions.
diff --git a/Charts/Classes/Charts/BarLineChartViewBase.swift b/Charts/Classes/Charts/BarLineChartViewBase.swift
@@ -205,10 +205,7 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
             }
         }
 
-        // make sure the graph values and grid cannot be drawn outside the content-rect
-        CGContextSaveGState(context)
-        CGContextClipToRect(context, _viewPortHandler.contentRect)
-
+        // The renderers are responsible for clipping, to account for line-width center etc.
         _xAxisRenderer?.renderGridLines(context: context)
         _leftYAxisRenderer?.renderGridLines(context: context)
         _rightYAxisRenderer?.renderGridLines(context: context)
@@ -226,6 +223,9 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
             _rightYAxisRenderer?.renderLimitLines(context: context)
         }
 
+        // make sure the data cannot be drawn outside the content-rect
+        CGContextSaveGState(context)
+        CGContextClipToRect(context, _viewPortHandler.contentRect)
         renderer?.drawData(context: context)
 
         // if highlighting is enabled
@@ -238,9 +238,6 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
 
         renderer!.drawExtras(context: context)
 
-        CGContextSaveGState(context)
-        CGContextClipToRect(context, _viewPortHandler.contentRect)
-
         if !_xAxis.isDrawLimitLinesBehindDataEnabled
         {
             _xAxisRenderer?.renderLimitLines(context: context)
@@ -254,8 +251,6 @@ public class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChar
             _rightYAxisRenderer?.renderLimitLines(context: context)
         }
 
-        CGContextRestoreGState(context)
-
         _xAxisRenderer.renderAxisLabels(context: context)
         _leftYAxisRenderer.renderAxisLabels(context: context)
         _rightYAxisRenderer.renderAxisLabels(context: context)

diff --git a/Charts/Classes/Renderers/XAxisRenderer.swift b/Charts/Classes/Renderers/XAxisRenderer.swift
@@ -293,6 +293,8 @@ public class XAxisRenderer: AxisRendererBase
         }
 
         CGContextSaveGState(context)
+        defer { CGContextRestoreGState(context) }
+        CGContextClipToRect(context, self.gridClippingRect)
 
         CGContextSetShouldAntialias(context, xAxis.gridAntialiasEnabled)
         CGContextSetStrokeColorWithColor(context, xAxis.gridColor.CGColor)
@@ -322,8 +324,13 @@ public class XAxisRenderer: AxisRendererBase
 
             drawGridLine(context: context, x: position.x, y: position.y)
         }
-
-        CGContextRestoreGState(context)
+    }
+
+    public var gridClippingRect: CGRect
+    {
+        var contentRect = viewPortHandler?.contentRect ?? CGRectZero
+        contentRect.insetInPlace(dx: -(self.axis?.gridLineWidth ?? 0.0) / 2.0, dy: 0.0)
+        return contentRect
     }
 
     public func drawGridLine(context context: CGContext, x: CGFloat, y: CGFloat)
@@ -347,6 +354,7 @@ public class XAxisRenderer: AxisRendererBase
     {
         guard let
             xAxis = self.axis as? ChartXAxis,
+            viewPortHandler = self.viewPortHandler,
             transformer = self.transformer
             else { return }
 
@@ -357,8 +365,6 @@ public class XAxisRenderer: AxisRendererBase
             return
         }
 
-        CGContextSaveGState(context)
-
         let trans = transformer.valueToPixelMatrix
 
         var position = CGPoint(x: 0.0, y: 0.0)
@@ -371,16 +377,20 @@ public class XAxisRenderer: AxisRendererBase
             {
                 continue
             }
-
+
+            CGContextSaveGState(context)
+            defer { CGContextRestoreGState(context) }
+            var clippingRect = viewPortHandler.contentRect
+            clippingRect.insetInPlace(dx: -l.lineWidth / 2.0, dy: 0.0)
+            CGContextClipToRect(context, clippingRect)
+
             position.x = CGFloat(l.limit)
             position.y = 0.0
             position = CGPointApplyAffineTransform(position, trans)
 
             renderLimitLineLine(context: context, limitLine: l, position: position)
             renderLimitLineLabel(context: context, limitLine: l, position: position, yOffset: 2.0 + l.yOffset)
         }
-
-        CGContextRestoreGState(context)
     }
 
     private var _limitLineSegmentsBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())

diff --git a/Charts/Classes/Renderers/XAxisRendererHorizontalBarChart.swift b/Charts/Classes/Renderers/XAxisRendererHorizontalBarChart.swift
@@ -188,6 +188,13 @@ public class XAxisRendererHorizontalBarChart: XAxisRenderer
             angleRadians: angleRadians)
     }
 
+    public override var gridClippingRect: CGRect
+    {
+        var contentRect = viewPortHandler?.contentRect ?? CGRectZero
+        contentRect.insetInPlace(dx: 0.0, dy: -(self.axis?.gridLineWidth ?? 0.0) / 2.0)
+        return contentRect
+    }
+
     private var _gridLineSegmentsBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())
 
     public override func drawGridLine(context context: CGContext, x: CGFloat, y: CGFloat)
@@ -275,8 +282,6 @@ public class XAxisRendererHorizontalBarChart: XAxisRenderer
             return
         }
 
-        CGContextSaveGState(context)
-
         let trans = transformer.valueToPixelMatrix
 
         var position = CGPoint(x: 0.0, y: 0.0)
@@ -289,6 +294,12 @@ public class XAxisRendererHorizontalBarChart: XAxisRenderer
             {
                 continue
             }
+
+            CGContextSaveGState(context)
+            defer { CGContextRestoreGState(context) }
+            var clippingRect = viewPortHandler.contentRect
+            clippingRect.insetInPlace(dx: 0.0, dy: -l.lineWidth / 2.0)
+            CGContextClipToRect(context, clippingRect)
 
             position.x = 0.0
             position.y = CGFloat(l.limit)
@@ -364,7 +375,5 @@ public class XAxisRendererHorizontalBarChart: XAxisRenderer
                 }
             }
         }
-
-        CGContextRestoreGState(context)
     }
 }
diff --git a/Charts/Classes/Renderers/YAxisRenderer.swift b/Charts/Classes/Renderers/YAxisRenderer.swift
@@ -179,6 +179,8 @@ public class YAxisRenderer: AxisRendererBase
             let positions = transformedPositions()
 
             CGContextSaveGState(context)
+            defer { CGContextRestoreGState(context) }
+            CGContextClipToRect(context, self.gridClippingRect)
 
             CGContextSetShouldAntialias(context, yAxis.gridAntialiasEnabled)
             CGContextSetStrokeColorWithColor(context, yAxis.gridColor.CGColor)
@@ -199,8 +201,6 @@ public class YAxisRenderer: AxisRendererBase
             {
                 drawGridLine(context: context, position: positions[i])
             }
-
-            CGContextRestoreGState(context)
         }
 
         if yAxis.drawZeroLineEnabled
@@ -210,6 +210,13 @@ public class YAxisRenderer: AxisRendererBase
         }
     }
 
+    public var gridClippingRect: CGRect
+    {
+        var contentRect = viewPortHandler?.contentRect ?? CGRectZero
+        contentRect.insetInPlace(dx: 0.0, dy: -(self.axis?.gridLineWidth ?? 0.0) / 2.0)
+        return contentRect
+    }
+
     private var _gridLineBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())
 
     public func drawGridLine(
@@ -261,6 +268,10 @@ public class YAxisRenderer: AxisRendererBase
             else { return }
 
         CGContextSaveGState(context)
+        defer { CGContextRestoreGState(context) }
+        var clippingRect = viewPortHandler.contentRect
+        clippingRect.insetInPlace(dx: 0.0, dy: yAxis.zeroLineWidth / 2.0)
+        CGContextClipToRect(context, clippingRect)
 
         CGContextSetStrokeColorWithColor(context, zeroLineColor.CGColor)
         CGContextSetLineWidth(context, yAxis.zeroLineWidth)
@@ -279,8 +290,6 @@ public class YAxisRenderer: AxisRendererBase
         CGContextMoveToPoint(context, viewPortHandler.contentLeft, pos.y - 1.0)
         CGContextAddLineToPoint(context, viewPortHandler.contentRight, pos.y - 1.0)
         CGContextDrawPath(context, CGPathDrawingMode.Stroke)
-
-        CGContextRestoreGState(context)
     }
 
     private var _limitLineSegmentsBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())
@@ -315,6 +324,12 @@ public class YAxisRenderer: AxisRendererBase
                 continue
             }
 
+            CGContextSaveGState(context)
+            defer { CGContextRestoreGState(context) }
+            var clippingRect = viewPortHandler.contentRect
+            clippingRect.insetInPlace(dx: 0.0, dy: -l.lineWidth / 2.0)
+            CGContextClipToRect(context, clippingRect)
+
             position.x = 0.0
             position.y = CGFloat(l.limit)
             position = CGPointApplyAffineTransform(position, trans)

diff --git a/Charts/Classes/Renderers/YAxisRendererHorizontalBarChart.swift b/Charts/Classes/Renderers/YAxisRendererHorizontalBarChart.swift
@@ -188,6 +188,13 @@ public class YAxisRendererHorizontalBarChart: YAxisRenderer
         }
     }
 
+    public override var gridClippingRect: CGRect
+    {
+        var contentRect = viewPortHandler?.contentRect ?? CGRectZero
+        contentRect.insetInPlace(dx: -(self.axis?.gridLineWidth ?? 0.0) / 2.0, dy: 0.0)
+        return contentRect
+    }
+
     private var _gridLineBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())
 
     public override func drawGridLine(
@@ -239,6 +246,10 @@ public class YAxisRendererHorizontalBarChart: YAxisRenderer
             else { return }
 
         CGContextSaveGState(context)
+        defer { CGContextRestoreGState(context) }
+        var clippingRect = viewPortHandler.contentRect
+        clippingRect.insetInPlace(dx: yAxis.zeroLineWidth / 2.0, dy: 0.0)
+        CGContextClipToRect(context, clippingRect)
 
         CGContextSetStrokeColorWithColor(context, zeroLineColor.CGColor)
         CGContextSetLineWidth(context, yAxis.zeroLineWidth)
@@ -257,8 +268,6 @@ public class YAxisRendererHorizontalBarChart: YAxisRenderer
         CGContextMoveToPoint(context, pos.x - 1.0, viewPortHandler.contentTop)
         CGContextAddLineToPoint(context, pos.x - 1.0, viewPortHandler.contentBottom)
         CGContextDrawPath(context, CGPathDrawingMode.Stroke)
-
-        CGContextRestoreGState(context)
     }
 
     private var _limitLineSegmentsBuffer = [CGPoint](count: 2, repeatedValue: CGPoint())
@@ -293,6 +302,12 @@ public class YAxisRendererHorizontalBarChart: YAxisRenderer
                 continue
             }
 
+            CGContextSaveGState(context)
+            defer { CGContextRestoreGState(context) }
+            var clippingRect = viewPortHandler.contentRect
+            clippingRect.insetInPlace(dx: -l.lineWidth / 2.0, dy: 0.0)
+            CGContextClipToRect(context, clippingRect)
+
             position.x = CGFloat(l.limit)
             position.y = 0.0
             position = CGPointApplyAffineTransform(position, trans)

diff --git a/ChartsDemo/Classes/Demos/LineChart2ViewController.xib b/ChartsDemo/Classes/Demos/LineChart2ViewController.xib
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="10117" systemVersion="15G31" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES">
     <dependencies>
         <deployment identifier="iOS"/>
         <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>