AZAlert.swift

//
//  AZAlert.swift
//  HelloAlertSwiftUI
//
//  Created by Mohammad Azam on 7/29/20.
//  Copyright © 2020 Mohammad Azam. All rights reserved.
//

import SwiftUI

struct AZAlert: View {
    
    let screenSize = UIScreen.main.bounds
    var title: String = ""
    @Binding var isShown: Bool
    @Binding var text: String
    var onDone: (String) -> Void = { _ in }
    var onCancel: () -> Void = { }
    
    
    var body: some View {
    
        VStack(spacing: 20) {
            Text(title)
                .font(.headline)
            Text("Message")
            TextField("", text: $text)
                .textFieldStyle(RoundedBorderTextFieldStyle())
            HStack(spacing: 20) {
                Button("Done") {
                    self.isShown = false
                    self.onDone(self.text)
                }
                Button("Cancel") {
                    self.isShown = false
                    self.onCancel()
                }
            }
        }
        .padding()
        .frame(width: screenSize.width * 0.7, height: screenSize.height * 0.3)
        .background(Color(#colorLiteral(red: 0.9268686175, green: 0.9416290522, blue: 0.9456014037, alpha: 1)))
        .clipShape(RoundedRectangle(cornerRadius: 20.0, style: .continuous))
        .offset(y: isShown ? 0 : screenSize.height)
        .animation(.spring())
        .shadow(color: Color(#colorLiteral(red: 0.8596749902, green: 0.854565084, blue: 0.8636032343, alpha: 1)), radius: 6, x: -9, y: -9)

    }
}

struct AZAlert_Previews: PreviewProvider {
    static var previews: some View {
        AZAlert(title: "Add Item", isShown: .constant(true), text: .constant(""))
    }
}

ContentView.swift

//
//  ContentView.swift
//  HelloAlertSwiftUI
//
//  Created by Mohammad Azam on 7/29/20.
//  Copyright © 2020 Mohammad Azam. All rights reserved.
//

import SwiftUI

struct ContentView: View {
    
    @State private var isPresented: Bool = false
    @State private var text: String = ""
    @State private var items = (1...5).map { "\($0)" }
    
    var body: some View {
        
        NavigationView {
           
            ZStack(alignment: .center) {
                VStack {
                    List(self.items, id: \.self) { index in
                        Text("\(index)")
                    }
                    Button("Show Alert") {
                        self.text = ""
                        self.isPresented = true
                    }
                    
                    Text(text)
                }
                AZAlert(title: "Add Item", isShown: $isPresented, text: $text, onDone: { text in
                    self.items.append(text)
                    })
                
            }
            
            .navigationBarTitle("Add Item")
            .navigationBarItems(trailing: Button("Add Item") {
                self.isPresented = true
            })
         
        }
    }
}

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