2020/02/10

contentViuew.swift

import SwiftUI

class CalcViewModel:ObservableObject{
    @Published var display = "0"
    @Published var middleTyping = false
    
    var displayValue:Double{
        get{
            return Double(display)!
        }
        set{
            display = String(newValue)
        }
    }
}

struct ContentView: View {
    
    @EnvironmentObject var calcVM: CalcViewModel
    
    var body: some View {
        
        VStack(spacing:10){
            
                Text(calcVM.display)
                .font(.largeTitle)
                .padding(.all)

                .frame(maxWidth:280,alignment: .trailing)
                .border(Color.red)

                .padding(.leading)
                .padding(.trailing)
            

            
            HStack{
                UnarySymbols()
                Digits()
//                UnarySymbols(display:$calcVM.display)
//                Digits(display:$calcVM.display)
            }
         }
    }
}


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

digit.swift

import SwiftUI


struct UnarySymbols:View {
    @EnvironmentObject var calcVM: CalcViewModel
    let symbols = ["π","√","±","="]

    
    var body:some View{

        VStack(spacing:10){
            ForEach(symbols,id:\.self){mathSymbol in
                       Button(mathSymbol,action:{
                        self.performOperation(mathSymbol)
                       })
                       .frame(width:60,height: 60)
                       .border(Color.red)
                       .font(.largeTitle)
                   }
        }
    }
    
    func performOperation(_ symbol:String){
        switch symbol {
        case "π":
            calcVM.displayValue = Double.pi
            self.calcVM.middleTyping = false
        case "√":
            calcVM.displayValue = sqrt(calcVM.displayValue)
            self.calcVM.middleTyping = false
        default:
            break
        }
    }
}



struct Digits: View {
    
    @EnvironmentObject var calcVM: CalcViewModel
    
    let digits = [[7,8,9],
                  [4,5,6],
                  [3,2,1],
                  [0]]
     
    @State var middleTyping = false
    
    var body: some View {
        VStack(spacing:10){
            ForEach(digits,id:\.self){rowDigits in
            HStack(spacing:12){
                ForEach(rowDigits,id:\.self){digit in
                    
                    Button("\(digit)", action:{
                        if self.calcVM.middleTyping{
                            self.calcVM.display = self.calcVM.display + "\(digit)"
                        }else{
                            self.calcVM.display = "\(digit)"
                            self.calcVM.middleTyping = true
                        }
                    })
                        .frame(width:60,height: 60)
                        .border(Color.red)
                        .font(.largeTitle)
                }
            }
        }
        
        }
    }
}