Trio/FreeAPSWatch WatchKit Extension/Views/BolusView.swift

import SwiftUI

struct BolusView: View {
    @EnvironmentObject var state: WatchStateModel

    @State var steps = 0.0

    var numberFormatter: NumberFormatter {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.minimum = 0
        formatter.maximum = Double((state.maxBolus ?? 5) / (state.bolusIncrement ?? 0.1)) as NSNumber
        formatter.maximumFractionDigits = 2
        formatter.minimumFractionDigits = 2
        formatter.allowsFloats = true
        return formatter
    }

    var body: some View {
        VStack(spacing: 16) {
            HStack {
                Button {
                    let newValue = steps - 1
                    steps = max(newValue, 0)
                } label: { Image(systemName: "minus") }
                    .frame(width: 50)
                Spacer()
                Text(numberFormatter.string(from: (steps * Double(state.bolusIncrement ?? 0.1)) as NSNumber)! + " U")
                    .font(.headline)
                    .focusable(true)
                    .digitalCrownRotation(
                        $steps,
                        from: 0,
                        through: Double((state.maxBolus ?? 5) / (state.bolusIncrement ?? 0.1)),
                        by: 1,
                        sensitivity: .medium,
                        isContinuous: false,
                        isHapticFeedbackEnabled: true
                    )
                Spacer()
                Button {
                    let newValue = steps + 1
                    steps = min(newValue, Double((state.maxBolus ?? 5) / (state.bolusIncrement ?? 0.1)))
                } label: { Image(systemName: "plus") }
                    .frame(width: 50)
            }

            HStack {
                Button {
                    state.isBolusViewActive = false
                }
                label: {
                    Image(systemName: "xmark.circle.fill")
                        .resizable()
                        .foregroundColor(.loopRed)
                        .frame(width: 30, height: 30)
                }
                Button {
                    enactBolus()
                }
                label: {
                    Image(systemName: "checkmark.circle.fill")
                        .resizable()
                        .foregroundColor(.loopGreen)
                        .frame(width: 30, height: 30)
                }
                .disabled(steps <= 0)
            }
        }
        .navigationTitle("Enact Bolus")
        .onAppear {
            steps = Double((state.bolusRecommended ?? 0) / (state.bolusIncrement ?? 0.1))
        }
    }

    private func enactBolus() {
        let amount = steps * Double(state.bolusIncrement ?? 0.1)
        state.enactBolus(amount: amount)
    }
}

struct BolusView_Previews: PreviewProvider {
    static var previews: some View {
        BolusView().environmentObject(WatchStateModel())
    }
}