Pop Up Menu Segue

Question

I am making a pop up menu in Swift on Xcode 8.2.1, and I can't figure out how to make it segue correctly (It is being created programmatically right now so that it will have a animation when you open it).

import UIKit

var clickj = false
var st = String()

class ViewController: UIViewController {

    var button = dropDownBtn()

    override func viewDidLoad() {
        super.viewDidLoad()

        if clickj == true {
            performSegue(withIdentifier: st, sender: nil)
        }

        // Do any additional setup after loading the view, typically from a nib.


        //Configure the button
        button = dropDownBtn.init(frame: CGRect(x: 0, y: 0, width: 0, height: 0))
        button.setTitle("Colors", for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false

        //Add Button to the View Controller
        self.view.addSubview(button)

        //button Constraints
        button.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
        button.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
        button.widthAnchor.constraint(equalToConstant: 100).isActive = true
        button.heightAnchor.constraint(equalToConstant: 40).isActive = true

        //Set the drop down menu's options
        button.dropView.dropDownOptions = ["Blue", "Choices"]

        }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

protocol dropDownProtocol {
    func dropDownPressed(string : String)
}

class dropDownBtn: UIButton, dropDownProtocol {

    func dropDownPressed(string: String) {
        print(string)
        st = string
        clickj = true
        self.dismissDropDown()
    }

    var dropView = dropDownView()

    var height = NSLayoutConstraint()


    override init(frame: CGRect) {
        super.init(frame: frame)

        self.backgroundColor = UIColor.darkGray

        dropView = dropDownView.init(frame: CGRect.init(x: 0, y: 0, width: 0, height: 0))
        dropView.delegate = self
        dropView.translatesAutoresizingMaskIntoConstraints = false
    }

    override func didMoveToSuperview() {
        self.superview?.addSubview(dropView)
        self.superview?.bringSubview(toFront: dropView)
        dropView.topAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
        dropView.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
        dropView.widthAnchor.constraint(equalTo: self.widthAnchor).isActive = true
        height = dropView.heightAnchor.constraint(equalToConstant: 0)
    }

    var isOpen = false
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if isOpen == false {

            isOpen = true

            NSLayoutConstraint.deactivate([self.height])

            if self.dropView.tableView.contentSize.height > 150 {
                self.height.constant = 150
            } else {
                self.height.constant = self.dropView.tableView.contentSize.height
            }


            NSLayoutConstraint.activate([self.height])

            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
                self.dropView.layoutIfNeeded()
                self.dropView.center.y += self.dropView.frame.height / 2
            }, completion: nil)

        } else {
            isOpen = false

            NSLayoutConstraint.deactivate([self.height])
            self.height.constant = 0
            NSLayoutConstraint.activate([self.height])
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
                self.dropView.center.y -= self.dropView.frame.height / 2
                self.dropView.layoutIfNeeded()
            }, completion: nil)

        }
    }

    func dismissDropDown() {
        isOpen = false
        NSLayoutConstraint.deactivate([self.height])
        self.height.constant = 0
        NSLayoutConstraint.activate([self.height])
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
            self.dropView.center.y -= self.dropView.frame.height / 2
            self.dropView.layoutIfNeeded()
        }, completion: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

class dropDownView: UIView, UITableViewDelegate, UITableViewDataSource  {

    var dropDownOptions = [String]()

    var tableView = UITableView()

    var delegate : dropDownProtocol!

    override init(frame: CGRect) {
        super.init(frame: frame)

        tableView.backgroundColor = UIColor.darkGray
        self.backgroundColor = UIColor.darkGray


        tableView.delegate = self
        tableView.dataSource = self

        tableView.translatesAutoresizingMaskIntoConstraints = false

        self.addSubview(tableView)

        tableView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dropDownOptions.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell()

        cell.textLabel?.text = dropDownOptions[indexPath.row]
        cell.backgroundColor = UIColor.darkGray
        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        self.delegate.dropDownPressed(string: dropDownOptions[indexPath.row])
        self.tableView.deselectRow(at: indexPath, animated: true)
    }

}

The problem is I have every thing set up to segue properly but I am still working on where I should place the if statement that will segue when the condition is true (mainly I am looking for some function I could place it in that would be called in the main ViewController when the button is clicked).

Answer 1

You are close... about all you need is to implement another delegate protocol.

Currently, your dropDownView is using dropDownProtocol to tell the button that a row was selected. What you also want is a protocol so the button can tell the view controller that it has dismissed itself, and to pass the selected string from the table.

Here is the code you presented, with very few changes. See the comments in the code. With your start, things should be pretty clear - feel free to ask for clarification if needed:

import UIKit

class ViewController: UIViewController,  dropDownCallBackProtocol {

    var button = dropDownBtn()

    override func viewDidLoad() {
        super.viewDidLoad()

        //Configure the button
        button = dropDownBtn.init(frame: CGRect(x: 0, y: 0, width: 0, height: 0))
        button.setTitle("Colors", for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false

        //Add Button to the View Controller
        self.view.addSubview(button)

        //button Constraints
        button.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
        button.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
        button.widthAnchor.constraint(equalToConstant: 100).isActive = true
        button.heightAnchor.constraint(equalToConstant: 40).isActive = true

        //Set the drop down menu's options
        button.dropView.dropDownOptions = ["Blue", "Choices"]

        // set the button's "vcCallBackDelegate"
        button.vcCallBackDelegate = self

    }

    func dropDownCompleted(string: String) {
        print("Inside View Controller:", string)
        // this will be called when the un-show-drop-down animation is finished
        // so you can perform your segue here
        // performSegue(withIdentifier: string, sender: nil)
    }

}

// protocol for the button to "call back" to the view controller (its parent)
protocol dropDownCallBackProtocol {
    func dropDownCompleted(string : String)
}

// protocol for the table to "call back" to the button (its parent)
protocol dropDownProtocol {
    func dropDownPressed(string : String)
}

class dropDownBtn: UIButton, dropDownProtocol {

    var vcCallBackDelegate: dropDownCallBackProtocol?

    func dropDownPressed(string: String) {
        print("Inside button class:", string)
        self.dismissDropDown(string)
    }

    var dropView = dropDownView()

    var height = NSLayoutConstraint()

    override init(frame: CGRect) {
        super.init(frame: frame)

        self.backgroundColor = UIColor.darkGray

        dropView = dropDownView.init(frame: CGRect.init(x: 0, y: 0, width: 0, height: 0))
        dropView.delegate = self
        dropView.translatesAutoresizingMaskIntoConstraints = false
    }

    override func didMoveToSuperview() {
        self.superview?.addSubview(dropView)
        self.superview?.bringSubview(toFront: dropView)
        dropView.topAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
        dropView.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
        dropView.widthAnchor.constraint(equalTo: self.widthAnchor).isActive = true
        height = dropView.heightAnchor.constraint(equalToConstant: 0)
    }

    var isOpen = false
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if isOpen == false {
            isOpen = true
            NSLayoutConstraint.deactivate([self.height])
            if self.dropView.tableView.contentSize.height > 150 {
                self.height.constant = 150
            } else {
                self.height.constant = self.dropView.tableView.contentSize.height
            }
            NSLayoutConstraint.activate([self.height])
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
                self.dropView.layoutIfNeeded()
                self.dropView.center.y += self.dropView.frame.height / 2
            }, completion: nil)
        } else {
            isOpen = false

            NSLayoutConstraint.deactivate([self.height])
            self.height.constant = 0
            NSLayoutConstraint.activate([self.height])
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
                self.dropView.center.y -= self.dropView.frame.height / 2
                self.dropView.layoutIfNeeded()
            }, completion: nil)

        }
    }

    func dismissDropDown(_ selectedString: String) {
        isOpen = false
        NSLayoutConstraint.deactivate([self.height])
        self.height.constant = 0
        NSLayoutConstraint.activate([self.height])
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseInOut, animations: {
            self.dropView.center.y -= self.dropView.frame.height / 2
            self.dropView.layoutIfNeeded()
        }, completion: {
            b in
            // tell the delegate the animation is complete, and pass the selected string
            self.vcCallBackDelegate?.dropDownCompleted(string: selectedString)
        })
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

class dropDownView: UIView, UITableViewDelegate, UITableViewDataSource  {

    var dropDownOptions = [String]()

    var tableView = UITableView()

    var delegate : dropDownProtocol!

    override init(frame: CGRect) {
        super.init(frame: frame)

        tableView.backgroundColor = UIColor.darkGray
        self.backgroundColor = UIColor.darkGray


        tableView.delegate = self
        tableView.dataSource = self

        tableView.translatesAutoresizingMaskIntoConstraints = false

        self.addSubview(tableView)

        tableView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dropDownOptions.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell()

        cell.textLabel?.text = dropDownOptions[indexPath.row]
        cell.backgroundColor = UIColor.darkGray
        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        self.delegate.dropDownPressed(string: dropDownOptions[indexPath.row])
        self.tableView.deselectRow(at: indexPath, animated: true)
    }

}