Draw multiple circles in view | ForEach - swift

Question

What I am trying to achieve
I am learning swift. I am trying to draw a line with multiple circle on it.
Then I want to be able to modify the Color of a circle when the user tap the circle.
And eventually do a drag and drop for moving the circle. Such as a custom bezier curve.
Currently, I am stuck on drawing multiple circle on the line.
What I trying to do :
1 - I create an array containing CGPoint
public var PointArray:[CGPoint]=[]
2 - Then doing an Identifiable struct
private struct Positions: Identifiable {
var id: Int
let point: CGPoint
}
3 - With CurveCustomInit, I fill the array. I got this error
No exact matches in call to instance method 'append'
I have done a lot, but I never success at using a ForEach function in one view.
I am using struct shapes as I want to customise shapes and then reuse the component. And also add a gesture function to each circle.
There is the whole code :
Note that a GeometryReader is sending the size of the view
import SwiftUI
public var PointArray:[CGPoint]=[]
public var PointArrayInit:Bool = false
private struct Positions: Identifiable {
var id: Int
let point: CGPoint
}
struct Arc: Shape {
var startAngle: Angle
var endAngle: Angle
var clockwise: Bool
var centerCustom:CGPoint
func path(in rect: CGRect) -> Path {
let rotationAdjustment = Angle.degrees(90)
let modifiedStart = startAngle - rotationAdjustment
let modifiedEnd = endAngle - rotationAdjustment
var path = Path()
path.addArc(center: centerCustom, radius: 20, startAngle: modifiedStart, endAngle: modifiedEnd, clockwise: !clockwise)
return path
}
}
struct CurveCustomInit: Shape {
private var Divider:Int = 10
func path(in rect: CGRect) -> Path {
var path = Path()
let xStep:CGFloat = DrawingZoneWidth / CGFloat(Divider)
let yStep:CGFloat = DrawingZoneHeight / 2
var xStepLoopIncrement:CGFloat = 0
path.move(to: CGPoint(x: 0, y: yStep))
var incr = 0
for _ in 0...Divider {
let Point:CGPoint = CGPoint(x: xStepLoopIncrement, y: yStep)
let value = Positions(id:incr, point:Point )
PointArray.append(value)
path.addLine(to: Point)
xStepLoopIncrement += xStep
incr += 1
}
PointArrayInit = true
return (path)
}
}
struct TouchCurveBasic: View {
var body: some View {
if !PointArrayInit {
// initialisation
CurveCustomInit()
.stroke(Color.red, style: StrokeStyle(lineWidth: 10, lineCap: .round, lineJoin: .round))
.frame(width: 300, height: 300)
.overlay(Arc(startAngle: .degrees(0),endAngle: .degrees(360),clockwise:true).stroke(Color.blue, lineWidth: 10))
} else {
// Update point
}
}
}
struct TouchCurveBasic_Previews: PreviewProvider {
static var previews: some View {
TouchCurveBasic()
}
}
What I am trying to achieve :

Answer 1

Your array PointArray contains values of type CGFloat but you are trying to append a value of type Positions. That's why you're getting this error.