Stop Watch

StopWatchManager.swift

import SwiftUI

class StopWatchManeger:ObservableObject{
    @Published var secondsElapsed = 0.0
    var timer = Timer()
    
    func start(){
        timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true){ timer in
            self.secondsElapsed += 0.1
        }
    }
}

timerContent.swift

import SwiftUI

struct ContentView: View {
    
    @ObservedObject var stopWatchManeger = StopWatchManeger()
    
    var body: some View {
        VStack {
            Text(String(format:"%.1f",stopWatchManeger.secondsElapsed))
                .font(.custom("Futura", size: 50))
                .padding(.top,200)
                .padding(.bottom,100)
                .padding(.trailing,100)
                .padding(.leading,100)
            
            Button(action: {self.stopWatchManeger.start()}){
                ExtractedView(label: "Start", buttonColor: .yellow, textColor: .black)
            }
            Spacer()
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

struct ExtractedView: View {
    var label:String
    var buttonColor:Color
    var textColor:Color
    
    var body: some View {
        Text(label)
            .foregroundColor(textColor)
            .padding(.vertical,20)
            .padding(.horizontal,90)
            .background(buttonColor)
            .cornerRadius(10)
    }
}