/*

    Copyright (C) 2017 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A table view controller that allows you to update the name of an 

               existing group.

*/

import UIKit

import Contacts

class UpdateGroupViewController: UITableViewController {

    // MARK: - Properties

    /// Name of the group to be updated.

    var name: String?

    /// Textfield used to enter a group name.

    @IBOutlet weak fileprivate var textField: UITextField!

    // MARK: - View Life Cycle

    override func viewDidLoad() {

        super.viewDidLoad()

        // Show the name of the group.

        if let displayedName = name {

            textField.text = displayedName

        }

    }

    // MARK: - UITextFieldDelegate

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

        // Hide the keyboard.

        textField.resignFirstResponder()

        // Show the Save button if the user has entered a name.

        navigationItem.rightBarButtonItem!.isEnabled = !(textField.text!.isEmpty)

        return true

    }

    // MARK: - UITableViewDelegate

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

        if indexPath.section == 0 && indexPath.row == 0 {

            textField.becomeFirstResponder()

        }

    }

    // MARK: - Navigation

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        // Send back the entered/updated name for the group.

        if navigationItem.rightBarButtonItem == sender as? UIBarButtonItem {

            name = textField.text

        }

    }

    // MARK: - Memory Management

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}