add a custom view for login

code/Complete/Landmarks/Landmarks/AppDelegate.swift

@@ -132,6 +132,25 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
         }
     }
 
+    public func signIn(username: String, password: String) {
+        AWSMobileClient.default().signIn(username: username, password: password) { (signInResult, error) in
+
+            if let error = error  {
+                print("\(error)")
+                // in real life, present an error message to user
+            } else if let signInResult = signInResult {
+                switch (signInResult.signInState) {
+                case .signedIn:
+                    print("User is signed in.")
+                case .smsMFA:
+                    print("SMS message sent to \(signInResult.codeDetails!.destination!)")
+                default:
+                    print("Sign In needs info which is not et supported.")
+                }
+            }
+        }
+    }
+
     public func signOut() {
         AWSMobileClient.default().signOut()
     }

code/Complete/Landmarks/Landmarks/CustomLoginView.swift

@@ -0,0 +1,56 @@
+import SwiftUI
+
+struct CustomLoginView : View {
+
+    @State private var username: String = ""
+    @State private var password: String = ""
+
+    private let app = UIApplication.shared.delegate as! AppDelegate
+
+    var body: some View { // The body of the screen view
+        VStack {
+            Image("turtlerock")
+            .resizable()
+            .aspectRatio(contentMode: ContentMode.fit)
+            .padding(Edge.Set.bottom, 20)
+
+            Text(verbatim: "Login").bold().font(.title)
+
+            Text(verbatim: "Explore Landmarks of the world")
+            .font(.subheadline)
+            .padding(EdgeInsets(top: 0, leading: 0, bottom: 70, trailing: 0))
+
+            TextField("Username", text: $username)
+            .autocapitalization(.none) //avoid autocapitalization of the first letter
+            .padding()
+            .cornerRadius(4.0)
+            .background(Color(UIColor.systemFill))
+            .padding(EdgeInsets(top: 0, leading: 0, bottom: 15, trailing: 0))
+
+            SecureField("Password", text: $password)
+            .padding()
+            .cornerRadius(4.0)
+            .background(Color(UIColor.systemFill))
+            .padding(.bottom, 10)
+
+            Button(action: { self.app.signIn(username: self.username, password: self.password) }) {
+                HStack() {
+                    Spacer()
+                    Text("Signin")
+                        .foregroundColor(Color.white)
+                        .bold()
+                    Spacer()
+                }
+
+            }.padding().background(Color.green).cornerRadius(4.0)
+        }.padding()
+    }
+}
+
+#if DEBUG
+struct ContentView_Previews : PreviewProvider {
+static var previews: some View {
+        CustomLoginView() // Renders your UI View on the XCode preview
+    }
+}
+#endif

code/Complete/Landmarks/Landmarks/LandingView.swift

@@ -11,19 +11,10 @@ struct LandingView: View {
 
     var body: some View {
 
-        let loginView = LoginViewController()
-
         return VStack {
             // .wrappedValue is used to extract the Bool from Binding<Bool> type
             if (!$user.isSignedIn.wrappedValue) {
-
-                ZStack {
-                    loginView
-                    Button(action: { loginView.authenticate() } ) {
-                        UserBadge().scaleEffect(0.5)
-                    }
-                }
-
+                CustomLoginView()
             } else {
                 LandmarkList().environmentObject(user)
             }