add value plot and fix crash when graphicView destroy with animating

Classes/Drawing/ValueDrawingLayer.swift

@@ -0,0 +1,66 @@
+//
+//  ValueDrawingLayer.swift
+//  ScrollableGraphView
+//
+//  Created by RiuHDuo on 2017/12/8.
+//  Copyright © 2017年 SGV. All rights reserved.
+//
+
+import UIKit
+
+class ValueDrawingLayer: ScrollableGraphViewDrawingLayer {
+
+    let font: UIFont
+    let color: UIColor
+
+    private var textLayers = [CATextLayer]()
+
+    init(frame: CGRect, font: UIFont, color: UIColor) {
+
+        self.font = font
+        self.color = color
+
+        super.init(viewportWidth: frame.size.width, viewportHeight: frame.size.height)
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    private func createDataPointPath() {
+
+        for layer in self.textLayers{
+            layer.removeFromSuperlayer()
+        }
+
+        guard let activePointsInterval = self.owner?.graphViewDrawingDelegate?.intervalForActivePoints() else{ return}
+        for i in activePointsInterval {
+
+            var location = CGPoint.zero
+
+            if let pointLocation = owner?.graphPoint(forIndex: i) {
+                location = pointLocation.location
+            }
+
+            let layer = CATextLayer()
+            layer.contentsScale = UIScreen.main.scale
+            layer.string  = String(format:"%.2f", self.owner?.data[i] ?? 0)
+            layer.bounds = CGRect(x: 0, y: 0, width: 60, height: 14)
+            layer.font = self.font.fontName as CFTypeRef
+            layer.fontSize = self.font.pointSize
+            layer.alignmentMode = kCAAlignmentCenter
+            layer.position = CGPoint(x: location.x, y: location.y - 10)
+            layer.foregroundColor = UIColor.black.cgColor
+            self.addSublayer(layer)
+            self.textLayers.append(layer)
+        }
+
+
+    }
+
+
+
+    override func updatePath() {
+        createDataPointPath()
+    }
+}

Classes/Plots/Plot.swift

@@ -6,7 +6,7 @@ open class Plot {
     // The id for this plot. Used when determining which data to give it in the dataSource
     open var identifier: String!
 
-    weak var graphViewDrawingDelegate: ScrollableGraphViewDrawingDelegate! = nil
+    weak var graphViewDrawingDelegate: ScrollableGraphViewDrawingDelegate? = nil
 
     // Animation Settings
     // ##################
@@ -22,6 +22,8 @@ open class Plot {
             }
         }
     }
+
+    var data = [Int:Double]()
     /// The animation style.
     open var adaptAnimationType = ScrollableGraphViewAnimationType.easeOut
     /// If adaptAnimationType is set to .Custom, then this is the easing function you would like applied for the animation.
@@ -64,7 +66,7 @@ open class Plot {
             }
         }
 
-        graphViewDrawingDelegate.updatePaths()
+        graphViewDrawingDelegate?.updatePaths()
     }
 
     private func animate(point: GraphPoint, to position: CGPoint, withDelay delay: Double = 0) {
@@ -151,9 +153,10 @@ open class Plot {
 
             let value = range.min
 
-            let position = graphViewDrawingDelegate.calculatePosition(atIndex: i, value: value)
-            let point = GraphPoint(position: position)
-            graphPoints.append(point)
+            if let position = graphViewDrawingDelegate?.calculatePosition(atIndex: i, value: value){
+                let point = GraphPoint(position: position)
+                graphPoints.append(point)
+            }
         }
     }
 
@@ -170,9 +173,10 @@ open class Plot {
 
             let value = data[dataPosition]
 
-            let newPosition = graphViewDrawingDelegate.calculatePosition(atIndex: i, value: value)
-            graphPoints[i].x = newPosition.x
-            graphPoints[i].y = newPosition.y
+            if let newPosition = graphViewDrawingDelegate?.calculatePosition(atIndex: i, value: value){
+                graphPoints[i].x = newPosition.x
+                graphPoints[i].y = newPosition.y
+            }
         }
     }
 
@@ -185,11 +189,12 @@ open class Plot {
             let dataPosition = index
             let value = data[dataPosition]
 
-            let newPosition = graphViewDrawingDelegate.calculatePosition(atIndex: activatedPointIndex, value: value)
-            graphPoints[activatedPointIndex].x = newPosition.x
-            graphPoints[activatedPointIndex].y = newPosition.y
-
-            index += 1
+            if let newPosition = graphViewDrawingDelegate?.calculatePosition(atIndex: activatedPointIndex, value: value){
+                graphPoints[activatedPointIndex].x = newPosition.x
+                graphPoints[activatedPointIndex].y = newPosition.y
+
+                index += 1
+            }
         }
     }
 
@@ -200,10 +205,11 @@ open class Plot {
         // For any visible points, kickoff the animation to their new position after the axis' min/max has changed.
         var dataIndex = 0
         for pointIndex in pointsToAnimate {
-            let newPosition = graphViewDrawingDelegate.calculatePosition(atIndex: pointIndex, value: data[dataIndex])
-            let point = graphPoints[pointIndex]
-            animate(point: point, to: newPosition, withDelay: Double(dataIndex) * delay)
-            dataIndex += 1
+            if let newPosition = graphViewDrawingDelegate?.calculatePosition(atIndex: pointIndex, value: data[dataIndex]){
+                let point = graphPoints[pointIndex]
+                animate(point: point, to: newPosition, withDelay: Double(dataIndex) * delay)
+                dataIndex += 1
+            }
         }
     }
 

Classes/Plots/ValuePlot.swift

@@ -0,0 +1,31 @@
+//
+//  ValuePlot.swift
+//  ScrollableGraphView
+//
+//  Created by RiuHDuo on 2017/12/8.
+//  Copyright © 2017年 SGV. All rights reserved.
+//
+
+import UIKit
+
+open class ValuePlot: Plot {
+    private var dataPointLayer: ValueDrawingLayer?
+
+    open var font = UIFont.systemFont(ofSize: 10)
+    open var color = UIColor.black
+
+    public init(identifier: String) {
+        super.init()
+        self.identifier = identifier
+    }
+
+    override func layers(forViewport viewport: CGRect) -> [ScrollableGraphViewDrawingLayer?] {
+        createLayers(viewport: viewport)
+        return [dataPointLayer]
+    }
+
+    private func createLayers(viewport: CGRect) {
+        dataPointLayer = ValueDrawingLayer(frame: viewport, font: font, color: color)
+        dataPointLayer?.owner = self
+    }
+}

Classes/ScrollableGraphView.swift

@@ -659,6 +659,7 @@ import UIKit
 
         for i in activeInterval.startIndex ..< activeInterval.endIndex {
             let dataForIndexI = dataSource?.value(forPlot: plot, atIndex: i) ?? 0
+            plot.data[i] = dataForIndexI
             dataForInterval.append(dataForIndexI)
         }