Hi community,

Writing an Exercise app and I am having issues to pass a value from 2 steppers to the timer. The timeRemaining initial value has to be equal to practiceTime / numberOfExercise When the START button os pressed the timer will start.

import SwiftUI

struct CounterView: View {

    @State private var practiceTime: Double = 30
    @State private var numberOfExercise = 5
    @State private var timeRemaining = 30
    @State private var isPracticeRunning = false

    let timer = Timer.publish(every: 1, on: .main, in: .common).autoconnect()

    var body: some View {
        NavigationView {
            VStack {

                Stepper("Number of Exercises:    \(numberOfExercise)", value: $numberOfExercise, in: 1...12, step: 1)
                    .padding(.horizontal)

                Stepper("Practice Time:    \(practiceTime.formatted()) min",value: $practiceTime, in: 5...60, step: 5)
                    .padding()

                Spacer()

                Text("Time: \(timeRemaining.formatted())")
                    .font(.title)
                    .foregroundColor(.secondary)
                Spacer()
                Button(action: {isPracticeRunning.toggle()}) {
                    Text(isPracticeRunning ? "Stop" : "Start")
                        .padding(20)
                        .foregroundColor(.primary)
                        .background(
                        RoundedRectangle(cornerRadius: 10)
                            .stroke(Color.primary, lineWidth: 2))
                }

                Spacer()
            }
            .navigationTitle(Text("Exercise Timer"))
        }
        .onReceive(timer) { time in
            guard self.isPracticeRunning else { return }
            if timeRemaining > 0 {
                timeRemaining -= 1
            }
        }
    }
}

Thanks,

Put this before the onReceive handler:

.onChange(of: numberOfExercise) { _ in
    timeRemaining = Int(practiceTime) / numberOfExercise
}
.onChange(of: practiceTime) { _ in
    timeRemaining = Int(practiceTime) / numberOfExercise
}

And if "The timeRemaining initial value has to be equal to practiceTime / numberOfExercise", shouldn't the initial value of timeRemaining be 6?

Thanks @roosterboy!

It's working now and yes it was supposed to be 6. Actually 360, because I need to change to seconds. Thanks again.