Currency Field SwiftUI

CurrencyField.swift

//
//  ContentView.swift
//  CurrencyField
//
//  Created by Yaser Almasri on 24/09/22.
//

import SwiftUI

struct ContentView: View {
    @State private var amount: String = "12345"
    
    var amountString: String {
        if self.amount.isEmpty {
            return currencyFormatter.string(from: NSNumber(value: Double(0)))!
        }
        let double = Double(self.amount)! / Double(100)
        return currencyFormatter.string(from: NSNumber(value: double))!
    }
    
    var body: some View {
        NavigationView {
            VStack {
                Text(self.amountString)
            }
        }
        .overlay(alignment: .bottom, content: {
            RoundedRectangle(cornerRadius: 10)
                .fill(Color.black)
                .frame(height: 250)
                .overlay {
                    VStack {
                        HStack {
                            DigitBtn(text: 1, numberString: self.$amount)
                            DigitBtn(text: 2, numberString: self.$amount)
                            DigitBtn(text: 3, numberString: self.$amount)
                        }
                        HStack {
                            DigitBtn(text: 4, numberString: self.$amount)
                            DigitBtn(text: 5, numberString: self.$amount)
                            DigitBtn(text: 6, numberString: self.$amount)
                        }
                        HStack {
                            DigitBtn(text: 7, numberString: self.$amount)
                            DigitBtn(text: 8, numberString: self.$amount)
                            DigitBtn(text: 9, numberString: self.$amount)
                        }
                        HStack {
                            DigitBtn(text: 0, numberString: self.$amount)
                            Button {
                                self.amount = String(self.amount.dropLast())
                            } label: {
                                Circle()
                                    .fill(Color.gray)
                                    .overlay {
                                        HStack {
                                            Image(systemName: "chevron.left")
                                                .foregroundColor(.white)
                                        }
                                    }
                            }

                        }
                    }
                }
        })
    }
}

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

struct DigitBtn: View {
    
    var text: Int
    @Binding var numberString: String
    
    var body: some View {
        Button {
            self.numberString = self.numberString.appending("\(text)")
        } label: {
            Rectangle()
                .fill(Color.gray)
                .overlay {
                    HStack {
                        Text("\(text)")
                            .foregroundColor(.white)
                    }
                }
        }
    }
}

let currencyFormatter: NumberFormatter = {
    let formatter = NumberFormatter()
    formatter.locale = Locale.current
    formatter.numberStyle = .currency
    formatter.maximumFractionDigits = 2
    return formatter
}()