ios - Focus on the next TextField/SecureField in SwiftUI

Question

I've built a login screen in SwiftUI. I want to focus on the password SecureField when the user is finished entering their email. How can I do this?

struct LoginView: View {
    @State var username: String = ""
    @State var password: String = ""

    var body: some View {
        ScrollView {
            VStack {
                TextField("Email", text: $username)
                    .padding()
                    .frame(width: 300)
                    .background(Color(UIColor.systemGray5))
                    .cornerRadius(5.0)
                    .padding(.bottom, 20)
                    .keyboardType(.emailAddress)

                SecureField("Password", text: $password)
                    .padding()
                    .frame(width: 300)
                    .background(Color(UIColor.systemGray5))
                    .cornerRadius(5.0)
                    .padding(.bottom, 20)

                Button(action: {

                }, label: {
                    Text("Login")
                        .padding()
                        .frame(width: 300)
                        .background((username.isEmpty || password.isEmpty) ? Color.gray : Color(UIColor.cricHQOrangeColor()))
                        .foregroundColor(.white)
                        .cornerRadius(5.0)
                        .padding(.bottom, 20)
                }).disabled(username.isEmpty || password.isEmpty)

Answer 1

When using UIKit, one would accomplish this by setting up the responder chain. This isn't available in SwiftUI, so until there is a more sophisticated focus and responder system, you can make use of the onEditingChanged changed of TextField

You will then need to manage the state of each field based on stored State variables. It may end up being more work than you want to do.

Fortunately, you can fall back to UIKit in SwiftUI by using UIViewRepresentable.

Here is some code that manages the focus of text fields using the UIKit responder system:

import SwiftUI

struct KeyboardTypeView: View {
    @State var firstName = ""
    @State var lastName = ""
    @State var focused: [Bool] = [true, false]

    var body: some View {
        Form {
            Section(header: Text("Your Info")) {
                TextFieldTyped(keyboardType: .default, returnVal: .next, tag: 0, text: self.$firstName, isfocusAble: self.$focused)
                TextFieldTyped(keyboardType: .default, returnVal: .done, tag: 1, text: self.$lastName, isfocusAble: self.$focused)
                Text("Full Name :" + self.firstName + " " + self.lastName)
            }
        }
}
}



struct TextFieldTyped: UIViewRepresentable {
    let keyboardType: UIKeyboardType
    let returnVal: UIReturnKeyType
    let tag: Int
    @Binding var text: String
    @Binding var isfocusAble: [Bool]

    func makeUIView(context: Context) -> UITextField {
        let textField = UITextField(frame: .zero)
        textField.keyboardType = self.keyboardType
        textField.returnKeyType = self.returnVal
        textField.tag = self.tag
        textField.delegate = context.coordinator
        textField.autocorrectionType = .no

        return textField
    }

    func updateUIView(_ uiView: UITextField, context: Context) {
        if isfocusAble[tag] {
            uiView.becomeFirstResponder()
        } else {
            uiView.resignFirstResponder()
        }
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, UITextFieldDelegate {
        var parent: TextFieldTyped

        init(_ textField: TextFieldTyped) {
            self.parent = textField
        }

        func updatefocus(textfield: UITextField) {
            textfield.becomeFirstResponder()
        }

func textFieldShouldReturn(_ textField: UITextField) -> Bool {

            if parent.tag == 0 {
                parent.isfocusAble = [false, true]
                parent.text = textField.text ?? ""
            } else if parent.tag == 1 {
                parent.isfocusAble = [false, false]
                parent.text = textField.text ?? ""
         }
        return true
        }

    }
}

You can refer to this question to get more information about this particular approach.

Hope this helps!