Is there a way to add paths to an already rendered path - swiftui

Question

TL;DR - I would like to add a Path or a Shape ? to an existing Shape and would like to know if I can somehow use path.addPath(...) See image for a visual of what I mean
I posted a question earlier about this but don't think I phrased it well and very possibly went about it the wrong way. All I would like to do is to add shapes to an existing shape. I see that Path has a method addPath(:) that lets us add one path to another.. and that would be perfect if I could figure out where to do it at. Here is my current attempt:
import SwiftUI
struct ContentView: View {
#State private var path = Path()
var body: some View {
VStack {
MyShape()
.stroke(lineWidth: 3)
.padding()
HStack {
AddHorizontalLineView()
AddVerticalLineView()
AddSquareView()
AddDiagonalLineView()
}
}
}
private func addBoxToPath(_ path: Path) -> Path { <-- No where to call this
var workingPath = path
workingPath.addRect(workingPath.boundingRect)
return workingPath
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct MyShape: Shape {
func path(in rect: CGRect) -> Path {
var path = Path()
path.addRect(rect)
return path
}
}
struct AddHorizontalLineView: View {
var body: some View {
Button(action: {}){
Rectangle()
.stroke()
.overlay(
HorizontalWire()
.stroke()
.padding()
)
}.frame(width: 50, height: 50)
}
}
struct AddVerticalLineView: View {
var body: some View {
Button(action: { }){
Rectangle()
.stroke()
.overlay(
VerticalWire()
.stroke()
.padding()
)
}.frame(width: 50, height: 50)
}
}
struct AddSquareView: View {
var body: some View {
Button(action: {
}){
Rectangle()
.stroke()
.overlay(
Rectangle()
.stroke()
.padding()
)
}.frame(width: 50, height: 50)
}
}
struct AddDiagonalLineView: View {
var body: some View {
Button(action: {}){
Rectangle()
.stroke()
.overlay(
DiagonalWire()
.stroke()
.foregroundColor(.red)
.padding()
)
}
.frame(width: 50, height: 50)
}
}
struct DiagonalWire: Shape {
func path(in rect: CGRect) -> Path {
var path = Path()
path.move(to: CGPoint(x: rect.minX, y: rect.minY))
path.addLine(to: CGPoint(x: rect.maxX, y: rect.maxY))
return path
}
}
struct VerticalWire: Shape {
func path(in rect: CGRect) -> Path {
var path = Path()
path.move(to: CGPoint(x: rect.midX, y: rect.minY))
path.addLine(to: CGPoint(x: rect.midX, y: rect.maxY))
return path
}
}
struct HorizontalWire: Shape {
func path(in rect: CGRect) -> Path {
var path = Path()
path.move(to: CGPoint(x: rect.minX, y: rect.midY))
path.addLine(to: CGPoint(x: rect.maxX, y: rect.midY))
return path
}
}
Can paths be added dynamically like this or the entire setup needs to be done beforehand in path(in:) method of every type that conforms to Shape
I hope my question makes more sense now..

Answer 1

You can pass the Path into MyShape (although it really has very little point then -- you could just render the Path itself).
Here's a simple example (with some of your buttons removed since it'll be a very amount of work to hook up all of the logic). I also had to add an additional rect to the Path to start with, since your addBoxToPath depends on there being something in the Path so that the boundingBox isn't just a 0x0 rect:
struct ContentView: View {
#State private var path = Path()
var body: some View {
VStack {
MyShape(path: path)
.stroke(lineWidth: 3)
.padding()
HStack {
Button(action: {
path = addBoxToPath(path)
}) {
Text("add")
}
}
}.onAppear {
path.addRect(CGRect(origin: .zero, size: CGSize(width: 200, height: 200)))
}
}
private func addBoxToPath(_ path: Path) -> Path {
var workingPath = path
workingPath.addRect(workingPath.boundingRect.insetBy(dx: -5, dy: -5))
return workingPath
}
}
struct MyShape: Shape {
var path : Path
func path(in rect: CGRect) -> Path {
return path
}
}