Swift4 TableView Sample (備忘録)

ViewController.swift

//
//  ViewController.swift
//  Sample
//

import UIKit


// MARK: -
extension ViewController {
    
    internal struct TableDef {
        
        //~~~ 各セクション (今回は共通で使い回す) ~~~~
        //項目名: 各セクション
        static let Section1Rows = [
            "cell A",
            "cell B",
            "cell C",
            ]
        
        enum Section1RowIndex: Int, Codable {
            case
            cell_A = 0,
            cell_B = 1,
            cell_C = 2
        }
        
        
        //~~~ セクション (以下の３つの配列の順序を合わせる) ~~~
        //セクション名
        static let Section = [
            "section 0",
            "section 1",
            "section 2",
            ]
        
        enum SectionRowIndex: Int, Codable {
            case
            section0 = 0,
            section1 = 1,
            section2 = 2
        }
        
        //項目名 (各セクションをまとめる)
        static let Rows = [
            TableDef.Section1Rows,
            TableDef.Section1Rows,
            TableDef.Section1Rows,
            ]
        
        
        //項目名を返す
        static func row(_ indexPath: IndexPath) -> String? {
            guard (0 <= indexPath.section), (indexPath.section < Rows.count) else {
                return nil
            }
            
            let lists = Rows[indexPath.section]
            
            guard (0 <= indexPath.row), (indexPath.row < lists.count) else {
                return nil
            }
            
            //正常終了
            return lists[indexPath.row]
        }
    }
}


// MARK: -
class ViewController: UIViewController {
    
    @IBOutlet weak var tableView: UITableView!
    
    //TableView の開閉用
    fileprivate var openedSections = Set<Int>()
    
    //KVO
    fileprivate var keyValueObservations = [NSKeyValueObservation]()
    
    
    //破棄
    deinit {
        self.removeKVO()
    }
}


// MARK: -
extension ViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.initKVO()
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}


// MARK: - KVO (KeyValueObserver)
extension ViewController {
    
    //KVO解除
    fileprivate func removeKVO() {
        
        for keyValueObservation in self.keyValueObservations {
            keyValueObservation.invalidate()
        }
        
        self.keyValueObservations.removeAll()
    }
    
    
    //KVO登録
    fileprivate func initKVO() {
        
//        //KVO: ... https://qiita.com/BlueEventHorizon/items/bf37428b54b937728dc7
//        if let status = xxx.status {
//
//            let kvo = status.observe(\.xxx) { (status, change) in
//                //change is Always nil. (⇨ Objective-Cで表現できるプロパティではない...ということ。)
//                print(change)
//
//                //TableViewを更新
//                self.updateSection(xxx: status.xxx)
//            }
//
//            self.keyValueObservations.append(kvo)
//        }
    }
}


// MARK: -
extension ViewController: UITableViewDataSource, UITableViewDelegate {
    
    // MARK: - Table view data source
    // UITableViewController の時は override
    
    func numberOfSections(in tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return TableDef.Section.count
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        
        //開いているセクション
        if self.openedSections.contains(section) {
            
            // セクションに入るセルの数を返す
            let count = TableDef.Rows[section].count
            return count
        }
        
        return 0
    }
    
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        let text = TableDef.Section[section]
        return text
    }
    
    //セクションヘッダを表示
    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        
        //TEST: たたみたくないセクション
        if (false) {
            let list: [Int] = [
            ]
            
            if (list.contains(section)) {
                return nil
            }
        }
        
        //ジェスチャーを追加
        if (true) {
            let view = UITableViewHeaderFooterView()
            let gesture = UITapGestureRecognizer(target: self, action: #selector(self.tapSectionHeader(_:)))
            
            view.addGestureRecognizer(gesture)
            view.tag = section
            
            return view
        }
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        //セルの作成
        let cell = self.createCell(tableView, indexPath)
        
//        //通常例
//        let cell = UITableViewCell(style: .value1, reuseIdentifier: "cell")
//        //let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
//
//        //Configure the cell...
        
        return cell
    }
    
    
    //セルをタップ
    func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
        
        if (self.isTouchCellIndexPath(indexPath)) {
            return indexPath
        }
        
        return nil
    }
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        //print(indexPath)
        
        //セルから指を離したときにコマンドを実行
        self.onClickCell(indexPath)
    }
}


// MARK: - TableView (Private Method)
extension ViewController {
    
    //セクションヘッダをタップしたとき(for ジェスチャー)
    @objc fileprivate func tapSectionHeader(_ sender: UIGestureRecognizer) {
        if let section = sender.view?.tag {
            
            //MEMO .fade がアコーディオンみたいで一番いいけど、たまに崩れる...
            var animation = UITableViewRowAnimation.automatic
            
            if self.openedSections.contains(section) {
                self.openedSections.remove(section)
                animation = .left
            } else {
                self.openedSections.insert(section)
                animation = .right
            }
            
            //セクションを更新 (アニメーションあり)
            self.tableView.reloadSections(IndexSet(integer: section), with: animation)
        }
    }
    
    //セルをタップ
    @objc fileprivate func tapCell(_ sendor: UILongPressGestureRecognizer) {
        
        switch sendor.state {
        case .began, .ended:
            
            //print(sendor.view)
            if let cell = sendor.view as? UITableViewCell {
                if let indexPath = self.tableView.indexPath(for: cell) {
                    
                    if (sendor.state == .began) {
                        self.tableView.selectRow(at: indexPath, animated: true, scrollPosition: .none)
                    } else {
                        self.tableView.deselectRow(at: indexPath, animated: true)
                        
                        self.tableView(self.tableView, didSelectRowAt: indexPath)
                    }
                }
            }
            break
            
        default:
            break
        }
    }
    
    
    //セルの作成
    internal func createCell(_ tableView: UITableView, _ indexPath: IndexPath) -> UITableViewCell {
        
        //セルの作成
        let cell = UITableViewCell(style: .value1, reuseIdentifier: "cell")
        
        if (true) {
            //デバッグ用
            cell.textLabel?.text        = TableDef.row(indexPath)
            cell.detailTextLabel?.text  = self.getString(indexPath)
            //cell.accessoryType = UITableViewCellAccessoryType.disclosureIndicator
        }
        
        //選択状態 (セルによっては有効にしたい)
        cell.selectionStyle = self.isTouchCellIndexPath(indexPath) ? (.default) : (.none)
        
        //指を離したときに .selectionStyle を元に戻したい
        if (cell.selectionStyle == .default) {
            
            // https://qiita.com/taketomato/items/e0e45f0d768109abef2f
            let gesture = UILongPressGestureRecognizer(target: self, action: #selector(tapCell(_:)))
            gesture.minimumPressDuration = 0
            cell.addGestureRecognizer(gesture)
        }
        
        return cell
    }
    
    
    //セルの更新
    internal func updateCell(_ indexPath: IndexPath, _ text: String) {
        
        //self.tableView.reloadRows(at: [indexPath], with: .automatic)
        if let cell = self.tableView.cellForRow(at: indexPath) /* as? UITableViewCell */ {
            cell.detailTextLabel?.text = text
        }
    }
}


// MARK: - セルのタップ (セルをボタンのように扱う)
extension ViewController {
    
    //タップ可能なセル番号かどうか？
    fileprivate func isTouchCellIndexPath(_ indexPath: IndexPath) -> Bool {
        
        //タップしたい項目 だけを登録
        let list: [Int : [Int]] = [
            TableDef.SectionRowIndex.section0.rawValue :
                [
                    TableDef.Section1RowIndex.cell_A.rawValue,
                    TableDef.Section1RowIndex.cell_B.rawValue,
                    TableDef.Section1RowIndex.cell_C.rawValue,
            ],
            
            TableDef.SectionRowIndex.section2.rawValue :
                [
                    TableDef.Section1RowIndex.cell_B.rawValue,
            ],
            ]
        
        return list[indexPath.section]?.contains(indexPath.row) ?? false
    }
    
    
    //セルをタップ
    fileprivate func onClickCell(_ indexPath: IndexPath) {
        
        //TODO: タップした時のコマンドを記述
        
        switch indexPath.section {
        case TableDef.SectionRowIndex.section0.rawValue:
            self.testCommand(section0: indexPath.row)
            break
            
        case TableDef.SectionRowIndex.section1.rawValue:
            self.testCommand(section1: indexPath.row)
            break
            
        case TableDef.SectionRowIndex.section2.rawValue:
            self.testCommand(section2: indexPath.row)
            break
            
        default:
            break
        }
    }
    
    
    //テスト
    fileprivate func testCommand(section0 row: Int) {
        let data = TableDef.SectionRowIndex.section0.rawValue
        
        self.testCommand(section: data, row: row)
    }
    fileprivate func testCommand(section1 row: Int) {
        let data = TableDef.SectionRowIndex.section1.rawValue
        
        self.testCommand(section: data, row: row)
    }
    fileprivate func testCommand(section2 row: Int) {
        let data = TableDef.SectionRowIndex.section2.rawValue
        
        self.testCommand(section: data, row: row)
    }
    
    //テスト (今回は共通)
    fileprivate func testCommand(section: Int, row: Int) {
        
        switch row {
        case TableDef.Section1RowIndex.cell_A.rawValue:
            print("tap A ... ", "section:", section, ", row:", row)
            break
            
        case TableDef.Section1RowIndex.cell_B.rawValue:
            print("tap B ... ", "section:", section, ", row:", row)
            break
            
        case TableDef.Section1RowIndex.cell_C.rawValue:
            print("tap C ... ", "section:", section, ", row:", row)
            break
            
        default:
            break
        }
        
    }
}



// MARK: - TableView (Private Method ... Update Section)
extension ViewController {
    
    //各セクションの文言を更新 (今回は共通メソッド ... 実際はセクションごとで用意)
    fileprivate func updateSection(dummyData: Int) {
        
        //TODO: セクションの指定 (今回は引数を仮で使用)
        //let section = TableDef.SectionRowIndex.section0.rawValue
        let section = dummyData
        
        //TODO: 更新する行を指定
        let rows: [TableDef.Section1RowIndex] = [
            .cell_A,
            .cell_B,
            .cell_C,
        ]
        
        for row in rows {
            
            //TODO: セルのデータ設定
            let text = self.getString(data: dummyData, row: row.rawValue)
            let indexPath = IndexPath(row: row.rawValue, section: section)
            
            self.updateCell(indexPath, text)
        }
    }
}


// MARK: - TableView で表示する文言 (KVO などのデータを String　にしたり...)
extension ViewController {
    
    fileprivate func getString(_ indexPath: IndexPath) -> String {
        
        var result: String = "---"
        
        //TODO: 各セクションごとでセルに表示する文言を調整するメソッドを用意 (今回は共通)
        switch indexPath.section {
            
        case TableDef.SectionRowIndex.section0.rawValue,
             TableDef.SectionRowIndex.section1.rawValue,
             TableDef.SectionRowIndex.section2.rawValue:
            
            result = self.getString(data:indexPath.section, row:indexPath.row)
            break;
            
        default:
            break;
        }
        
        
        return result
    }
    
    //セクションごとで セルに表示する文言を調整する (今回は共通)
    //引数は各セクションごとのデータになるようにしてます
    fileprivate func getString(data: Int, row: Int) -> String {
        
        var result: String = "(nil)"
        
        switch row {
            
        case TableDef.Section1RowIndex.cell_A.rawValue:
            result = String(format:"section:%d - Cell A", data)
            break
            
        case TableDef.Section1RowIndex.cell_B.rawValue:
            result = String(format:"section:%d - Cell B", data)
            break
            
        case TableDef.Section1RowIndex.cell_C.rawValue:
            result = String(format:"section:%d - Cell C", data)
            break
            
        default:
            break
        }
        
        return result
    }
}