快速范围滑块无法正常工作。找不到错误

Question

我有这个范围滑块，我从swift 3.0重写到swift 2.2 - 但出了问题 - 我似乎无法找到问题。所以现在我与你们分享:)

问题是，我只能拖动其中一个拇指，只有一次，然后一切都卡住了。

我的演示项目可以在这里找到：https://github.com/nharbo/RangeSliderSwift2.2 它只有2个类，所以如果你有时间，我会爱你看看它！

而且，这里是从类，我怀疑一个代码是一个制造麻烦：

/// Range slider track layer. Responsible for drawing the horizontal track 
public class RangeSliderTrackLayer: CALayer { 

/// owner slider 
weak var rangeSlider: NHRangeSlider? 

/// draw the track between 2 thumbs 
/// 
/// - Parameter ctx: current graphics context 
public override func drawInContext(ctx: CGContext) { 
    super.drawInContext(ctx) 
    guard let slider = rangeSlider else { 
     return 
    } 

    // Clip 
    let cornerRadius = bounds.height * slider.curvaceousness/2.0 
    let path = UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius) 

    CGContextAddPath(ctx, path.CGPath) 

    // Fill the track 
    CGContextSetFillColorWithColor(ctx, slider.trackTintColor.CGColor) 
    CGContextAddPath(ctx, path.CGPath) 
    CGContextFillPath(ctx) 

    // Fill the highlighted range 
    CGContextSetFillColorWithColor(ctx, slider.trackHighlightTintColor.CGColor) 
    let lowerValuePosition = CGFloat(slider.positionForValue(slider.lowerValue)) 
    let upperValuePosition = CGFloat(slider.positionForValue(slider.upperValue)) 
    let rect = CGRect(x: lowerValuePosition, y: 0.0, width: upperValuePosition - lowerValuePosition, height: bounds.height) 
    CGContextFillRect(ctx, rect) 
} 
} 

/// the thumb for upper , lower bounds 

public class RangeSliderThumbLayer: CALayer { 

/// owner slider 
weak var rangeSlider: NHRangeSlider? 

/// whether this thumb is currently highlighted i.e. touched by user 
public var highlighted: Bool = false { 
    didSet { 
     setNeedsDisplay() 
    } 
} 

/// stroke color 
public var strokeColor: UIColor = UIColor.grayColor() { 
    didSet { 
     setNeedsDisplay() 
    } 
} 

/// line width 
public var lineWidth: CGFloat = 0.5 { 
    didSet { 
     setNeedsDisplay() 
    } 
} 

/// draw the thumb 
/// 
/// - Parameter ctx: current graphics context 
public override func drawInContext(ctx: CGContext) { 
    super.drawInContext(ctx) 
    guard let slider = rangeSlider else { 
     return 
    } 

    let thumbFrame = bounds.insetBy(dx: 2.0, dy: 2.0) 
    let cornerRadius = thumbFrame.height * slider.curvaceousness/2.0 
    let thumbPath = UIBezierPath(roundedRect: thumbFrame, cornerRadius: cornerRadius) 

    // Fill 
    CGContextSetFillColorWithColor(ctx, slider.thumbTintColor.CGColor) 
    CGContextAddPath(ctx, thumbPath.CGPath) 
    CGContextFillPath(ctx) 

    // Outline 
    CGContextSetStrokeColorWithColor(ctx, strokeColor.CGColor) 
    CGContextSetLineWidth(ctx, lineWidth) 
    CGContextAddPath(ctx, thumbPath.CGPath) 
    CGContextStrokePath(ctx) 

    if highlighted { 
     CGContextSetFillColorWithColor(ctx, UIColor(white: 0.0, alpha: 0.1).CGColor) 
     CGContextAddPath(ctx, thumbPath.CGPath) 
     CGContextFillPath(ctx) 
    } 
} 
} 

/// Range slider view with upper, lower bounds 
@IBDesignable 
public class NHRangeSlider: UIControl { 

// MARK: properties 

/// minimum value 
@IBInspectable public var minimumValue: Double = 0.0 { 
    willSet(newValue) { 
     assert(newValue < maximumValue, "NHRangeSlider: minimumValue should be lower than maximumValue") 
    } 
    didSet { 
     updateLayerFrames() 
    } 
} 

/// max value 
@IBInspectable public var maximumValue: Double = 100.0 { 
    willSet(newValue) { 
     assert(newValue > minimumValue, "NHRangeSlider: maximumValue should be greater than minimumValue") 
    } 
    didSet { 
     updateLayerFrames() 
    } 
} 

/// value for lower thumb 
@IBInspectable public var lowerValue: Double = 0.0 { 
    didSet { 
     if lowerValue < minimumValue { 
      lowerValue = minimumValue 
     } 
     updateLayerFrames() 
    } 
} 

/// value for upper thumb 
@IBInspectable public var upperValue: Double = 100.0 { 
    didSet { 
     if upperValue > maximumValue { 
      upperValue = maximumValue 
     } 
     updateLayerFrames() 
    } 
} 

/// stepValue. If set, will snap to discrete step points along the slider . Default to nil 
@IBInspectable public var stepValue: Double? = nil { 
    willSet(newValue) { 
     if newValue != nil { 
      assert(newValue! > 0, "NHRangeSlider: stepValue must be positive") 
     } 
    } 
    didSet { 
     if let val = stepValue { 
      if val <= 0 { 
       stepValue = nil 
      } 
     } 

     updateLayerFrames() 
    } 
} 

/// minimum distance between the upper and lower thumbs. 
@IBInspectable public var gapBetweenThumbs: Double = 2.0 

/// tint color for track between 2 thumbs 
@IBInspectable public var trackTintColor: UIColor = UIColor(white: 0.9, alpha: 1.0) { 
    didSet { 
     trackLayer.setNeedsDisplay() 
    } 
} 

/// track highlight tint color 
@IBInspectable public var trackHighlightTintColor: UIColor = UIColor(red: 0.0, green: 0.45, blue: 0.94, alpha: 1.0) { 
    didSet { 
     trackLayer.setNeedsDisplay() 
    } 
} 

/// thumb tint color 
@IBInspectable public var thumbTintColor: UIColor = UIColor.whiteColor() { 
    didSet { 
     lowerThumbLayer.setNeedsDisplay() 
     upperThumbLayer.setNeedsDisplay() 
    } 
} 

/// thumb border color 
@IBInspectable public var thumbBorderColor: UIColor = UIColor.grayColor() { 
    didSet { 
     lowerThumbLayer.strokeColor = thumbBorderColor 
     upperThumbLayer.strokeColor = thumbBorderColor 
    } 
} 

/// thumb border width 
@IBInspectable public var thumbBorderWidth: CGFloat = 0.5 { 
    didSet { 
     lowerThumbLayer.lineWidth = thumbBorderWidth 
     upperThumbLayer.lineWidth = thumbBorderWidth 
    } 
} 

/// set 0.0 for square thumbs to 1.0 for circle thumbs 
@IBInspectable public var curvaceousness: CGFloat = 1.0 { 
    didSet { 
     if curvaceousness < 0.0 { 
      curvaceousness = 0.0 
     } 

     if curvaceousness > 1.0 { 
      curvaceousness = 1.0 
     } 

     trackLayer.setNeedsDisplay() 
     lowerThumbLayer.setNeedsDisplay() 
     upperThumbLayer.setNeedsDisplay() 
    } 
} 

/// previous touch location 
private var previouslocation = CGPoint() 

/// track layer 
private let trackLayer = RangeSliderTrackLayer() 

/// lower thumb layer 
public let lowerThumbLayer = RangeSliderThumbLayer() 

/// upper thumb layer 
public let upperThumbLayer = RangeSliderThumbLayer() 

/// thumb width 
private var thumbWidth: CGFloat { 
    return CGFloat(bounds.height) 
} 

/// frame 
override public var frame: CGRect { 
    didSet { 
     updateLayerFrames() 
    } 
} 

// MARK: init methods 
override public init(frame: CGRect) { 
    super.init(frame: frame) 
    initializeLayers() 
} 

required public init?(coder: NSCoder) { 
    super.init(coder: coder) 
    initializeLayers() 
} 

// MARK: layers 

/// layout sub layers 
/// 
/// - Parameter of: layer 
public override func layoutSublayersOfLayer(layer: CALayer) { 
    super.layoutSublayersOfLayer(layer) 
    updateLayerFrames() 
} 

/// init layers 
private func initializeLayers() { 
    layer.backgroundColor = UIColor.clearColor().CGColor 

    trackLayer.rangeSlider = self 
    trackLayer.contentsScale = UIScreen.mainScreen().scale 
    layer.addSublayer(trackLayer) 

    lowerThumbLayer.rangeSlider = self 
    lowerThumbLayer.contentsScale = UIScreen.mainScreen().scale 
    layer.addSublayer(lowerThumbLayer) 

    upperThumbLayer.rangeSlider = self 
    upperThumbLayer.contentsScale = UIScreen.mainScreen().scale 
    layer.addSublayer(upperThumbLayer) 
} 

/// update layer frames 
public func updateLayerFrames() { 
    CATransaction.begin() 
    CATransaction.setDisableActions(true) 

    trackLayer.frame = bounds.insetBy(dx: 0.0, dy: bounds.height/3) 
    trackLayer.setNeedsDisplay() 

    let lowerThumbCenter = CGFloat(positionForValue(lowerValue)) 
    lowerThumbLayer.frame = CGRect(x: lowerThumbCenter - thumbWidth/2.0, y: 0.0, width: thumbWidth, height: thumbWidth) 
    lowerThumbLayer.setNeedsDisplay() 

    let upperThumbCenter = CGFloat(positionForValue(upperValue)) 
    upperThumbLayer.frame = CGRect(x: upperThumbCenter - thumbWidth/2.0, y: 0.0, width: thumbWidth, height: thumbWidth) 
    upperThumbLayer.setNeedsDisplay() 

    CATransaction.commit() 
} 

/// thumb x position for new value 
public func positionForValue(value: Double) -> Double { 
    if (maximumValue == minimumValue) { 
     return 0 
    } 

    return Double(bounds.width - thumbWidth) * (value - minimumValue)/(maximumValue - minimumValue) 
     + Double(thumbWidth/2.0) 
} 

/// bound new value within lower and upper value 
/// 
/// - Parameters: 
/// - value: value to set 
/// - lowerValue: lower value 
/// - upperValue: upper value 
/// - Returns: current value 
public func boundValue(value: Double, toLowerValue lowerValue: Double, upperValue: Double) -> Double { 
    return min(max(value, lowerValue), upperValue) 
} 

// MARK: - Touches 

/// begin tracking 
public override func beginTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool { 
    super.beginTrackingWithTouch(touch, withEvent: event) 

    // set highlighted positions for lower and upper thumbs 
    if lowerThumbLayer.frame.contains(previouslocation) { 
     lowerThumbLayer.highlighted = true 
    } 

    if upperThumbLayer.frame.contains(previouslocation) { 
     upperThumbLayer.highlighted = true 
    } 

    return lowerThumbLayer.highlighted || upperThumbLayer.highlighted 
} 

/// update positions for lower and upper thumbs 
public override func continueTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool { 
    super.continueTrackingWithTouch(touch, withEvent: event) 

    let location = touch.locationInView(self) 

    // Determine by how much the user has dragged 
    let deltaLocation = Double(location.x - previouslocation.x) 
    var deltaValue: Double = 0 

    if (bounds.width != bounds.height) { 
     deltaValue = (maximumValue - minimumValue) * deltaLocation/Double(bounds.width - bounds.height) 
    } 

    previouslocation = location 

    // if both are highlighted. we need to decide which direction to drag 
    if lowerThumbLayer.highlighted && upperThumbLayer.highlighted { 

     if deltaLocation > 0 { 
      // left to right 
      upperValue = boundValue(upperValue + deltaValue, toLowerValue: lowerValue + gapBetweenThumbs, upperValue: maximumValue) 
     } 
     else { 
      // right to left 
      lowerValue = boundValue(lowerValue + deltaValue, toLowerValue: minimumValue, upperValue: upperValue - gapBetweenThumbs) 
     } 
    } 
    else { 

     // Update the values 
     if lowerThumbLayer.highlighted { 
      lowerValue = boundValue(lowerValue + deltaValue, toLowerValue: minimumValue, upperValue: upperValue - gapBetweenThumbs) 
     } else if upperThumbLayer.highlighted { 
      upperValue = boundValue(upperValue + deltaValue, toLowerValue: lowerValue + gapBetweenThumbs, upperValue: maximumValue) 
     } 
    } 

    // only send changed value if stepValue is not set. We will trigger this later in endTracking 
    if stepValue == nil { 
     sendActionsForControlEvents(.ValueChanged) 
    } 

    return true 
} 

/// end touch tracking. Unhighlight the two thumbs 
public override func endTrackingWithTouch(touch: UITouch?, withEvent event: UIEvent?) { 
    super.endTrackingWithTouch(touch, withEvent: event) 

    lowerThumbLayer.highlighted = false 
    upperThumbLayer.highlighted = false 

    // let slider snap after user stop dragging 
    if let stepValue = stepValue { 
     lowerValue = round(lowerValue/stepValue) * stepValue 
     upperValue = round(upperValue/stepValue) * stepValue 
     sendActionsForControlEvents(.ValueChanged) 
    } 
} 

} 

Answer 1

我不知道的预期功能的休息，但拇指停止后拖第一次尝试，因为您正在检查拇指位置而不是先前位置变量，而不是NHRangeSlider.swift的beginTracking方法中的当前触摸位置。如果您按照以下方式修改方法，则可以根据需要多次拖动拇指（但我不知道其余功能是如何受此影响的，因为您需要查看这会如何影响以前的位置变量） ：

open override func beginTracking(_ touch: UITouch, with event: UIEvent?) -> Bool { 
     super.beginTracking(touch, with: event) 

     print("beginTrackingWithTouch") 

     let location = touch.location(in: self) 
     // set highlighted positions for lower and upper thumbs 
     if lowerThumbLayer.frame.contains(location) { 
      print("1111") 
      lowerThumbLayer.highlighted = true 
     } 

     if upperThumbLayer.frame.contains(location) { 
      print("2222") 
      upperThumbLayer.highlighted = true 
     } 

     return lowerThumbLayer.highlighted || upperThumbLayer.highlighted 
    } 

注：的代码是雨燕3.0格式，因为我安装斯威夫特2.x的没有做。