swift - 使用 CAShapeLayer swift 创建带有阴影的自定义折线图
问题描述
我对Minh Nguyen的折线图进行了一定程度的修改，以显示两条线，一条用于收缩压，另一条用于舒张压。
第一张图片显示了图表的外观，第二张图片是我已经实现的。
struct PointEntry {
let systolic: Int
let diastolic: Int
let label: String
}
extension PointEntry: Comparable {
static func <(lhs: PointEntry, rhs: PointEntry) -> Bool {
return lhs.systolic < rhs.systolic || lhs.systolic < rhs.systolic
}
static func ==(lhs: PointEntry, rhs: PointEntry) -> Bool {
return lhs.systolic == rhs.systolic && lhs.diastolic == rhs.diastolic
}
}
class LineChart: UIView {
/// gap between each point
let lineGap: CGFloat = 30.0
/// preseved space at top of the chart
let topSpace: CGFloat = 20.0
/// preserved space at bottom of the chart to show labels along the Y axis
let bottomSpace: CGFloat = 40.0
/// The top most horizontal line in the chart will be 10% higher than the highest value in the chart
let topHorizontalLine: CGFloat = 110.0 / 100.0
/// Dot inner Radius
var innerRadius: CGFloat = 8
/// Dot outer Radius
var outerRadius: CGFloat = 12
var dataEntries: [PointEntry]? {
didSet {
self.setNeedsLayout()
}
}
/// Contains the main line which represents the data
private let dataLayer: CALayer = CALayer()
/// Contains dataLayer and gradientLayer
private let mainLayer: CALayer = CALayer()
/// Contains mainLayer and label for each data entry
private let scrollView: UIScrollView = {
let view = UIScrollView()
view.showsVerticalScrollIndicator = false
view.showsHorizontalScrollIndicator = false
return view
}()
/// Contains horizontal lines
private let gridLayer: CALayer = CALayer()
/// An array of CGPoint on dataLayer coordinate system that the main line will go through. These points will be calculated from dataEntries array
private var systolicDataPoint: [CGPoint]?
private var daistolicDataPoint: [CGPoint]?
override init(frame: CGRect) {
super.init(frame: frame)
setupView()
}
convenience init() {
self.init(frame: CGRect.zero)
setupView()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setupView()
}
private func setupView() {
mainLayer.addSublayer(dataLayer)
mainLayer.addSublayer(gridLayer)
scrollView.layer.addSublayer(mainLayer)
self.addSubview(scrollView)
}
override func layoutSubviews() {
scrollView.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: self.frame.size.height)
if let dataEntries = dataEntries {
scrollView.contentSize = CGSize(width: CGFloat(dataEntries.count) * lineGap + 30, height: self.frame.size.height)
mainLayer.frame = CGRect(x: 0, y: 0, width: CGFloat(dataEntries.count) * lineGap + 30, height: self.frame.size.height)
dataLayer.frame = CGRect(x: 0, y: topSpace, width: mainLayer.frame.width, height: mainLayer.frame.height - topSpace - bottomSpace)
systolicGradientLayer.frame = dataLayer.frame
diastolicGradientLayer.frame = dataLayer.frame
systolicDataPoint = convertDataEntriesToPoints(entries: dataEntries, isSystolic: true)
daistolicDataPoint = convertDataEntriesToPoints(entries: dataEntries, isSystolic: false)
gridLayer.frame = CGRect(x: 0, y: topSpace, width: CGFloat(dataEntries.count) * lineGap + 30, height: mainLayer.frame.height - topSpace - bottomSpace)
clean()
drawHorizontalLines()
drawVerticleLine()
drawChart(for: systolicDataPoint, color: .blue)
drawChart(for: daistolicDataPoint, color: .green)
drawLables()
}
}
/// Convert an array of PointEntry to an array of CGPoint on dataLayer coordinate system
/// - Parameter entries: Arrays of PointEntry
private func convertDataEntriesToPoints(entries: [PointEntry], isSystolic: Bool) -> [CGPoint] {
var result: [CGPoint] = []
// let gridValues: [CGFloat] = [0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1.0, 1.05]
for (index, value) in entries.enumerated() {
let difference: CGFloat = 0.125 / 30
let userValue: CGFloat = isSystolic ? CGFloat(value.systolic) : CGFloat(value.diastolic)
var height = (userValue - 30.0) * difference
height = (1.0 - height) * gridLayer.frame.size.height
let point = CGPoint(x: CGFloat(index)*lineGap + 40, y: height)
result.append(point)
}
return result
}
/// Draw a zigzag line connecting all points in dataPoints
private func drawChart(for points: [CGPoint]?, color: UIColor) {
if let dataPoints = points, dataPoints.count > 0 {
guard let path = createPath(for: points) else { return }
let lineLayer = CAShapeLayer()
lineLayer.path = path.cgPath
lineLayer.strokeColor = color.cgColor
lineLayer.fillColor = UIColor.clear.cgColor
dataLayer.addSublayer(lineLayer)
}
}
/// Create a zigzag bezier path that connects all points in dataPoints
private func createPath(for points: [CGPoint]?) -> UIBezierPath? {
guard let dataPoints = points, dataPoints.count > 0 else {
return nil
}
let path = UIBezierPath()
path.move(to: dataPoints[0])
for i in 1..<dataPoints.count {
path.addLine(to: dataPoints[i])
}
return path
}
/// Create titles at the bottom for all entries showed in the chart
private func drawLables() {
if let dataEntries = dataEntries,
dataEntries.count > 0 {
for i in 0..<dataEntries.count {
let textLayer = CATextLayer()
textLayer.frame = CGRect(x: lineGap*CGFloat(i) - lineGap/2 + 40, y: mainLayer.frame.size.height - bottomSpace/2 - 8, width: lineGap, height: 16)
textLayer.foregroundColor = UIColor.black.cgColor
textLayer.backgroundColor = UIColor.clear.cgColor
textLayer.alignmentMode = CATextLayerAlignmentMode.center
textLayer.contentsScale = UIScreen.main.scale
textLayer.font = CTFontCreateWithName(UIFont.systemFont(ofSize: 0).fontName as CFString, 0, nil)
textLayer.fontSize = 11
textLayer.string = dataEntries[i].label
mainLayer.addSublayer(textLayer)
}
}
}
/// Create horizontal lines (grid lines) and show the value of each line
private func drawHorizontalLines() {
let gridValues: [CGFloat] = [1.05, 1.0, 0.875, 0.75, 0.625, 0.5, 0.375, 0.25, 0.125]
let gridText = ["", "30", "60", "90", "120", "150", "180", "210", "240"]
for (index, value) in gridValues.enumerated() {
let height = value * gridLayer.frame.size.height
let path = UIBezierPath()
if value == gridValues.first! {
path.move(to: CGPoint(x: 30, y: height))
} else {
path.move(to: CGPoint(x: 28, y: height))
}
path.addLine(to: CGPoint(x: gridLayer.frame.size.width, y: height))
let lineLayer = CAShapeLayer()
lineLayer.path = path.cgPath
lineLayer.fillColor = UIColor.clear.cgColor
lineLayer.strokeColor = UIColor.black.cgColor
if value != gridValues.first! {
lineLayer.lineDashPattern = [4, 4]
}
lineLayer.lineWidth = 0.5
gridLayer.addSublayer(lineLayer)
let textLayer = CATextLayer()
textLayer.frame = CGRect(x: 4, y: height-8, width: 50, height: 16)
textLayer.foregroundColor = UIColor.black.cgColor
textLayer.backgroundColor = UIColor.clear.cgColor
textLayer.contentsScale = UIScreen.main.scale
textLayer.font = CTFontCreateWithName(UIFont.systemFont(ofSize: 0).fontName as CFString, 0, nil)
textLayer.fontSize = 12
textLayer.string = gridText[index]
gridLayer.addSublayer(textLayer)
}
}
private func drawVerticleLine() {
let height = gridLayer.frame.size.height * 1.05
let path = UIBezierPath()
path.move(to: CGPoint(x: 30, y: 0))
path.addLine(to: CGPoint(x: 30, y: height))
let lineLayer = CAShapeLayer()
lineLayer.path = path.cgPath
lineLayer.fillColor = UIColor.clear.cgColor
lineLayer.strokeColor = UIColor.black.cgColor
lineLayer.lineWidth = 0.5
gridLayer.addSublayer(lineLayer)
}
private func clean() {
mainLayer.sublayers?.forEach({
if $0 is CATextLayer {
$0.removeFromSuperlayer()
}
})
dataLayer.sublayers?.forEach({$0.removeFromSuperlayer()})
gridLayer.sublayers?.forEach({$0.removeFromSuperlayer()})
}
}
如何向第一张图片中显示的线条添加阴影并将简单的线条绘制动画添加到图表？
解决方案
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