UISearchBarにリストをくっつけてみた...なんか標準機能だけで出来そうな気もするけど

ListSearchBar.swift

import UIKit

class ListSearchBar: UISearchBar, UISearchBarDelegate, UITableViewDataSource, UITableViewDelegate {
    
    var myDelegate: UISearchBarDelegate? = nil
    lazy var tableView: UITableView = self.setupTableView()
    
    private var items = [String]()
    private var isShowList = false
    private var listHeight: CGFloat = 0.0
    
    // delegate設定を奪う
    // ほんちゃんは自分でつかいたいんで
    override var delegate: UISearchBarDelegate? {
        set {
            myDelegate = newValue
        }
        get {
            return myDelegate
        }
    }
    
    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup();
    }
    
    override func didMoveToSuperview() {
        if let s = self.superview {
            s.addSubview(self.tableView)
        } else {
            self.tableView.removeFromSuperview()
        }
    }
    
    deinit {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }
    
    func setup() {
        NSNotificationCenter.defaultCenter().addObserver(
            self,
            selector: "receiveKeyboardWillShowNotification:",
            name: UIKeyboardWillShowNotification,
            object: nil
        )
        NSNotificationCenter.defaultCenter().addObserver(
            self,
            selector: "receiveKeyboardWillHideNotification:",
            name: UIKeyboardWillHideNotification,
            object: nil
        )
        
        super.delegate = self
        
        self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
        self.tableView.dataSource = self
        self.tableView.delegate = self
    }
    
    func setupTableView() -> UITableView {
        let tableView = UITableView(
            frame: CGRect(
                x:self.frame.origin.x,
                y:self.frame.origin.y + self.frame.size.height,
                width:self.frame.size.width,
                height:0),
            style: UITableViewStyle.Plain
        )
        return tableView
    }
    
    func setList(items: [String]) {
        self.items.removeAll(keepCapacity: false)
        for s in items {
            self.items.append(s)
        }
    }
    
    func showList() {
        if self.isShowList || self.listHeight <= 0 {
            return
        }
        self.superview?.bringSubviewToFront(self.tableView)
        self.isShowList = true
        self.tableView.reloadData()
        self.tableView.frame = CGRect(
            x: self.frame.origin.x,
            y: self.frame.origin.y + self.frame.size.height,
            width: self.frame.size.width,
            height: self.listHeight
        )
        self.tableView.scrollRectToVisible(CGRect.zeroRect, animated: false)
    }
    
    func hideList() {
        if !self.isShowList {
            return
        }
        self.isShowList = false
        self.tableView.frame = CGRect(
            x: self.frame.origin.x,
            y: self.frame.origin.y + self.frame.size.height,
            width: self.frame.size.width,
            height: 0
        )
    }
    
    // MARK: UITableViewDataSource
    
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.items.count
    }
    
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
        cell.textLabel?.text = self.items[indexPath.row]
        return cell
    }
    
    // MARK: UITableViewDelegate
    func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        return 44
    }
    
    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        self.text = self.items[indexPath.row]
        self.hideList()
    }
    
    // MARK: NSNotification
    func receiveKeyboardWillShowNotification(notification: NSNotification) {
        if self.isFirstResponder() {
            var h = notification.userInfo![UIKeyboardFrameEndUserInfoKey]!.CGRectValue().size.height
            self.listHeight = (self.superview?.frame.size.height ?? 0) - h
            showList()
        }
    }
    
    func receiveKeyboardWillHideNotification(notification: NSNotification) {
        hideList()
    }
    
    // MARK: UISearchBarDelegate
    func searchBarShouldBeginEditing(searchBar: UISearchBar) -> Bool {
        return self.myDelegate?.searchBarShouldBeginEditing?(searchBar) ?? true
    }
    func searchBarTextDidBeginEditing(searchBar: UISearchBar) {
        showList()
        self.myDelegate?.searchBarTextDidBeginEditing?(searchBar)
    }
    func searchBarShouldEndEditing(searchBar: UISearchBar) -> Bool {
        return self.myDelegate?.searchBarShouldEndEditing?(searchBar) ?? true
    }
    func searchBarTextDidEndEditing(searchBar: UISearchBar) {
        self.myDelegate?.searchBarTextDidBeginEditing?(searchBar)
    }
    func searchBar(searchBar: UISearchBar, textDidChange searchText: String) {
        if !self.isShowList {
            showList()
        }
        self.myDelegate?.searchBar?(searchBar, textDidChange: searchText)
    }
    func searchBar(searchBar: UISearchBar, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
        return self.myDelegate?.searchBar?(searchBar, shouldChangeTextInRange: range, replacementText: text) ?? true
    }
    func searchBarSearchButtonClicked(searchBar: UISearchBar) {
        hideList()
        self.myDelegate?.searchBarSearchButtonClicked?(searchBar)
    }
    func searchBarBookmarkButtonClicked(searchBar: UISearchBar) {
        self.myDelegate?.searchBarBookmarkButtonClicked?(searchBar)
    }
    func searchBarCancelButtonClicked(searchBar: UISearchBar) {
        self.myDelegate?.searchBarCancelButtonClicked?(searchBar)
    }
    func searchBarResultsListButtonClicked(searchBar: UISearchBar) {
        self.myDelegate?.searchBarResultsListButtonClicked?(searchBar)
    }
    func searchBar(searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
        self.myDelegate?.searchBar?(searchBar, selectedScopeButtonIndexDidChange: selectedScope)
    }
}