// 菜鸟版
func square(x: Int) -> Int { return x * x }
var squaredOfFive = square(x: 5)
square(x: squaredOfFive) // 625

// 高手版
extension Int { 
 var squared: Int { return self * self }
}
5.squared // 25
5.squared.squared // 625

// 高手版
func printElementFromArray(a: [T]) {
        for element in a { 
            print(element) 
        } 
}

protocol TextViewControllerDelegate: NSObjectProtocol{
    // 点击delegate按钮回调
    func delegateBtnWillClick(message : String)
}

/MARK: - 点击代理传值按钮
func delegateBtnClick()
{
    print("代理传值按钮被点击")
    let str = "代理传值按钮被点击,把上个界面的值传了过来"
    delegate?.delegateBtnWillClick(str)
    self.navigationController?.popViewControllerAnimated(true)
}

import UIKit
import SnapKit
let newFeatureID = "newFeatureID"
class YMNewfeatureViewController: UICollectionViewController {
    /// 布局对象
    private var layout: UICollectionViewFlowLayout = YMNewfeatureLayout()
    init() {
        super.init(collectionViewLayout: layout)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        collectionView?.registerClass(YMNewfeatureCell.self, forCellWithReuseIdentifier: newFeatureID)
    }
    
    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return kNewFeatureCount
    }
    
    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(newFeatureID, forIndexPath: indexPath) as! YMNewfeatureCell
        cell.imageIndex = indexPath.item
        return cell
    }
    // 完全显示一个cell之后调用
    override func collectionView(collectionView: UICollectionView, didEndDisplayingCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: NSIndexPath) {
        let path = collectionView.indexPathsForVisibleItems().last!
        if path.item == (kNewFeatureCount - 1) {
            let cell = collectionView.cellForItemAtIndexPath(path) as! YMNewfeatureCell
            cell.startBtnAnimation()
        }
    }
}
/// YMNewfeatureCell
private class YMNewfeatureCell: UICollectionViewCell {
    
    private var imageIndex: Int? {
        didSet {
            iconView.image = UIImage(named: "walkthrough_\(imageIndex! + 1)")
        }
    }
    
    func startBtnAnimation() {
        startButton.hidden = false
        // 执行动画
        startButton.transform = CGAffineTransformMakeScale(0.0, 0.0)
        startButton.userInteractionEnabled = false
        
        // UIViewAnimationOptions(rawValue: 0) == OC knilOptions
        UIView.animateWithDuration(2, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 5, options: UIViewAnimationOptions(rawValue: 0), animations: { () -> Void in
            // 清空形变
            self.startButton.transform = CGAffineTransformIdentity
            }, completion: { (_) -> Void in
                self.startButton.userInteractionEnabled = true
        })
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        setupUI()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func setupUI() {
        contentView.addSubview(iconView)
        contentView.addSubview(startButton)
        
        iconView.snp_makeConstraints { (make) in
            make.edges.equalTo(contentView)
        }
        
        startButton.snp_makeConstraints { (make) in
            make.bottom.equalTo(contentView.snp_bottom).offset(-50)
            make.size.equalTo(CGSizeMake(150, 40))
            make.centerX.equalTo(0)
        }
    }
    
    private lazy var iconView = UIImageView()
    private lazy var startButton: UIButton = {
        let btn = UIButton()
        btn.setBackgroundImage(UIImage(named: "btn_begin"), forState: .Normal)
        btn.addTarget(self, action: #selector(startButtonClick), forControlEvents: .TouchUpInside)
        btn.layer.masksToBounds = true
        btn.hidden = true
        return btn
    }()
    
    @objc func startButtonClick() {
        UIApplication.sharedApplication().keyWindow?.rootViewController = YMTabBarController()
    }
}
private class YMNewfeatureLayout: UICollectionViewFlowLayout {
    /// 准备布局
    private override func prepareLayout() {
        // 设置 layout 布局
        itemSize = UIScreen.mainScreen().bounds.size
        minimumLineSpacing = 0
        minimumInteritemSpacing = 0
        scrollDirection = .Horizontal
        // 设置 contentView 属性
        collectionView?.showsVerticalScrollIndicator = false
        collectionView?.bounces = false
        collectionView?.pagingEnabled = true
    }
}

import UIKit
let homeCellID = "homeCellID"
class YMTopicViewController: YMBaseViewController, UITableViewDelegate, UITableViewDataSource, YMHomeCellDelegate {
    var type = Int()
    
    var tableView = UITableView()
    /// 首页列表数据
    var items = [YMHomeItem]()
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = YMGlobalColor()
        setupTableView()
        // 获取首页数据
        weak var weakSelf = self
        YMNetworkTool.shareNetworkTool.loadHomeInfo(type) { (homeItems) in
            weakSelf!.items = homeItems
            weakSelf?.tableView.reloadData()
        }
    }
    
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return items.count
    }
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let homeCell = tableView.dequeueReusableCellWithIdentifier(homeCellID) as! YMHomeCell
        homeCell.homeItem = items[indexPath.row]
        homeCell.delegate = self
        return homeCell
    }
    
    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        let detailVC = YMDetailViewController()
        detailVC.homeItem = items[indexPath.row]
        detailVC.title = "攻略详情"
        navigationController?.pushViewController(detailVC, animated: true)
    }
    
    
    func homeCellDidClickedFavoriteButton(button: UIButton) {
        print("favorite button click")
        let loginVC = YMLoginViewController()
        loginVC.title = "登录"
        let nav = YMNavigationController(rootViewController: loginVC)
        presentViewController(nav, animated: true, completion: nil)
    }
    
    func setupTableView() {
        let tableView = UITableView()
        tableView.frame = view.bounds
        tableView.delegate = self
        tableView.dataSource = self
        tableView.rowHeight = 160
        tableView.separatorStyle = .None
        tableView.contentInset = UIEdgeInsetsMake(kTitlesViewY + kTitlesViewH, 0, tabBarController!.tabBar.height, 0)
        tableView.scrollIndicatorInsets = tableView.contentInset
        let nib = UINib(nibName: String(YMHomeCell), bundle: nil)
        tableView.registerNib(nib, forCellReuseIdentifier: homeCellID)
        view.addSubview(tableView)
        self.tableView = tableView
    }
    
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    
    /*
     // MARK: - Navigation
     
     // In a storyboard-based application, you will often want to do a little preparation before navigation
     override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
     // Get the new view controller using segue.destinationViewController.
     // Pass the selected object to the new view controller.
     }
     */
    
}