How to update UIBezierpath and CAShapeLayer path with pan gesture of UIView? - swift

Question

'''
import UIKit
class CanvasView: UIView {
var circleViewTag = 1000
var coordinatePoints: [String] = ["243,103","534,86","243,286","426,286"] {
didSet {
self.updateCoordinateArray()
self.drawPoints()
}
}
fileprivate var coordArray: [CGPoint] = []
var shape = CAShapeLayer()
var path = UIBezierPath()
/*// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
// Drawing code
}*/
private func drawPoints() -> Void {
CommonMethods.printLog("\(coordinatePoints)")
self.layer.addSublayer(shape)
shape.opacity = 0.5
shape.lineWidth = 2
shape.lineJoin = CAShapeLayerLineJoin.miter
shape.strokeColor = UIColor.white.cgColor
shape.fillColor = UIColor(red: 1.0, green: 0.2, blue: 0.2, alpha: 0.2).cgColor
if let firstCoord = self.coordArray.first {
path.move(to: firstCoord)
}
for (index, cgPoint) in self.coordArray.enumerated() {
self.drawCircularPoint(points: cgPoint)
if index == 0 {
continue
}
path.addLine(to: cgPoint)
}
path.close()
shape.path = path.cgPath
//self.drawLineBetweenPoints()
}
private func drawCircularPoint(points: CGPoint) -> Void {
let circleView = UIView.init(frame: .zero)
circleViewTag = circleViewTag + 1
circleView.tag = circleViewTag
circleView.frame.size = CGSize.init(width: 30.0, height: 30.0)
circleView.layer.cornerRadius = 15.0
circleView.center = points
circleView.backgroundColor = .random()
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(self.draggedView(_:)))
panGesture.view?.tag = circleView.tag
circleView.isUserInteractionEnabled = true
circleView.addGestureRecognizer(panGesture)
self.addSubview(circleView)
}
#objc func draggedView(_ sender:UIPanGestureRecognizer){
guard let getTag = sender.view?.tag else { return }
if let viewToDrag = self.viewWithTag(getTag) as? UIView {
var currentPoint: CGPoint = .zero
if path.contains(viewToDrag.center) {
print("YES")
currentPoint = path.currentPoint
}
let translation = sender.translation(in: self)
viewToDrag.center = CGPoint(x: viewToDrag.center.x + translation.x, y: viewToDrag.center.y + translation.y)
sender.setTranslation(CGPoint.zero, in: self)
if sender.state == .began && currentPoint != .zero {
let coordinateIndex = self.coordArray.firstIndex { (cgpoint) -> Bool in
if currentPoint == cgpoint {
return true
}
return false
}
if coordinateIndex != nil {
self.coordArray[coordinateIndex!] = viewToDrag.center
self.shape.removeFromSuperlayer()
self.path.removeAllPoints()
self.setNeedsDisplay()
self.layer.addSublayer(self.shape)
self.shape.opacity = 0.5
self.shape.lineWidth = 2
self.shape.lineJoin = CAShapeLayerLineJoin.miter
self.shape.strokeColor = UIColor.white.cgColor
self.shape.fillColor = UIColor(red: 1.0, green: 0.2, blue: 0.2, alpha: 0.2).cgColor
if let firstCoord = self.coordArray.first {
path.move(to: firstCoord)
}
for (index, cgPoint) in self.coordArray.enumerated() {
//self.drawCircularPoint(points: cgPoint)
if index == 0 {
continue
}
path.addLine(to: cgPoint)
}
path.close()
shape.path = path.cgPath
}
}
}
//self.bringSubviewToFront(viewDrag)
}
private func updateCoordinateArray() -> Void {
for singleCoordinate in self.coordinatePoints {
if singleCoordinate.contains(",") == true {
let splitCoordinate = singleCoordinate.split(separator: ",")
if splitCoordinate.count == 2 {
let xPos = CGFloat(Float(splitCoordinate[0]) ?? 0.0)
let yPos = CGFloat(Float(splitCoordinate[1]) ?? 0.0)
let cgPoint = CGPoint(x: xPos, y: yPos)
self.coordArray.append(cgPoint)
}
}
}
var penultimateIndex: Int?
if let penultimateCoordinate = self.coordArray.penultimate() {
penultimateIndex = self.coordArray.firstIndex { (cgpoint) -> Bool in
if penultimateCoordinate == cgpoint {
return true
}
return false
}
}
var lastIndex: Int?
if let lastCoordinate = self.coordArray.last {
lastIndex = self.coordArray.firstIndex { (cgpoint) -> Bool in
if lastCoordinate == cgpoint {
return true
}
return false
}
}
if penultimateIndex != nil && lastIndex != nil {
self.coordArray.swapAt(penultimateIndex!, lastIndex!)
}
}
'''
I am creating a polygon using UIBezierpath and CAShapelayer. Added pan gesture on all 4 points that is UIView. When I drag the point A,B,C,D the expected behaviour is that bezierpath and CAShapelayer gets updated with the updated points. And when user drag the inner part of the shape all the path gets updated. But I am unable to update the path and shape. Can anyone help me with this?

Answer 1

yon set name for layer
var shape = CAShapeLayer()
shape.name = "name1"
and then, instead of updating, you can delete it by first searching by name, and then add