标题控件

//
//  PageTitleView.swift
//  标题头滑动
//
//  Created by Zhangguodong on 17/3/27.
//  Copyright © 2017年 ZGD. All rights reserved.
//

import UIKit
protocol PageTitleViewDelegate {
    func pageTitleView(pageTitleView:PageTitleView,selectedIndex index: Int) -> Void
}

// MARK:- 定义常量
private let kScrollLineH : CGFloat = 2
private let kNormalColor : (R:CGFloat, G:CGFloat, B:CGFloat) = (85, 85, 85)
private let kSelectColor : (R:CGFloat, G:CGFloat, B:CGFloat) = (255, 128, 0)

class PageTitleView: UIView {
    fileprivate var titles:[String]?
    init(frame: CGRect,titles:[String]) {
        super.init(frame: frame)
        backgroundColor = UIColor.orange
        self.titles = titles
        addChildView()
        
    }
    var delegate: PageTitleViewDelegate?
    
    fileprivate lazy var lables : [UILabel] = [UILabel]()
    var index: NSInteger = 0
    fileprivate  lazy var scrollView: UIScrollView = {
        let scrollView = UIScrollView(frame: self.bounds)
        scrollView.backgroundColor = UIColor.white
        scrollView.showsVerticalScrollIndicator = false
        return scrollView
    }()
    lazy var indicateLabel: UILabel = {
        let indicateLabel = UILabel()
        indicateLabel.backgroundColor = UIColor.randomColor()
        return indicateLabel
    }()
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

extension PageTitleView {
    func addChildView() -> Void {
        addSubview(scrollView)
        addLables()
    }
    //MARK: 添加label和指示控件
    func addLables() -> Void {
        let labelW = scrollView.frame.size.width / 4.0
        let labelH = scrollView.frame.size.height - kScrollLineH
        for (index,name) in (titles?.enumerated())! {
            let label = UILabel(frame: CGRect(x: labelW * CGFloat(index), y: 0, width: labelW, height: labelH))
            label.text = name
            label.tag = index
            label.isUserInteractionEnabled = true
            label.textAlignment = .center
            label.backgroundColor = UIColor.white
            label.textColor = UIColor(r: kNormalColor.R, g: kNormalColor.G, b: kNormalColor.B)
            if index == 0 {
                label.textColor = UIColor(r: kSelectColor.R, g: kSelectColor.G, b: kSelectColor.B)
            }
            let tapGesture = UITapGestureRecognizer(target: self, action: #selector(tapAction(tap:)))
            label.addGestureRecognizer(tapGesture)
            self.lables.append(label)
            scrollView.addSubview(label)
        }
        indicateLabel.frame = CGRect(x: 0, y: scrollView.frame.size.height - kScrollLineH, width: labelW, height: kScrollLineH)
        scrollView.addSubview(indicateLabel)
    }
    func tapAction(tap: UITapGestureRecognizer) -> Void {
        let currentlabel = tap.view as! UILabel
        let currentIndex = currentlabel.tag
        if currentIndex == index {
           return
        }else {
            delegate?.pageTitleView(pageTitleView: self, selectedIndex: currentIndex)
            currentlabel.textColor = UIColor(r: kSelectColor.R, g: kSelectColor.G, b: kSelectColor.B)
            let lastLabel = self.lables[index]
            lastLabel.textColor = UIColor(r: kNormalColor.R, g: kNormalColor.G, b: kNormalColor.B)
            UIView.animate(withDuration: 0.5, animations: {
                self.indicateLabel.frame.origin.x = self.frame.size.width / 4.0 * CGFloat(currentIndex)
            })
        }
        index = currentIndex
    }
    
}
//MARK: 暴露的方法
extension PageTitleView {
    func setTitleWithProgress(progress:CGFloat,sourceIndex:Int,targetIndex:Int) -> Void {
        //1.取出sourceLabel/targetLabel
        let sourceLabel = lables[sourceIndex]
        let targetLabel = lables[targetIndex]
        // 2.处理滑块的逻辑
        let moveTotalX = targetLabel.frame.origin.x - sourceLabel.frame.origin.x
        let moveX = moveTotalX * progress
        indicateLabel.frame.origin.x = moveX + sourceLabel.frame.origin.x
        //3.颜色渐变
        let colorDelta = (kSelectColor.R - kNormalColor.R,kSelectColor.G - kNormalColor.G,kSelectColor.B - kNormalColor.B)
        sourceLabel.textColor = UIColor(r: kSelectColor.R - colorDelta.0 * progress, g: kSelectColor.G - colorDelta.1 * progress, b: kSelectColor.B - colorDelta.2 * progress)
        targetLabel.textColor = UIColor(r: kNormalColor.0 + colorDelta.0 * progress, g: kNormalColor.1 + colorDelta.1 * progress, b: kNormalColor.2 + colorDelta.2 * progress)
        //4.更新下标
        index = targetIndex
    }
}

内容控件

//
//  PageContentView.swift
//  标题头滑动
//
//  Created by Zhangguodong on 17/3/27.
//  Copyright © 2017年 ZGD. All rights reserved.
//

import UIKit
protocol PageContentViewDelegate {
    func pageContentView(pageContentView:PageContentView,progress:CGFloat,sourceIndex:Int,targetIndex:Int) -> Void
}
class PageContentView: UIView {
    var childVCs:[UIViewController]?
    var delegate: PageContentViewDelegate?
    //点击的时候禁止走代理方法(scrollViewDidScroll)
    var forbidDelegate = false
    init(frame: CGRect,childVCs:[UIViewController]) {
        super.init(frame: frame)
        backgroundColor = UIColor.randomColor()
        self.childVCs = childVCs
        addSubview(collectionview)
    }
    fileprivate var startOffsetX : CGFloat = 0
    lazy var collectionview: UICollectionView = {
        let layout = FlowLayout()
        let collectionview = UICollectionView(frame: self.bounds, collectionViewLayout: layout)
        collectionview.dataSource = self
        collectionview.delegate = self
        collectionview.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell")
        return collectionview
    }()
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}
extension PageContentView:UICollectionViewDelegate,UICollectionViewDataSource {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return (self.childVCs?.count)!
    }
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
        let vc = self.childVCs?[indexPath.item]
        cell.contentView.addSubview((vc?.view)!)
        return cell
    }
}
//MARK: 判断左右
extension PageContentView {
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        forbidDelegate = false
        startOffsetX = scrollView.contentOffset.x
    }
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        if forbidDelegate  {
            return
        }
    let currentOffsetX = scrollView.contentOffset.x
    
        var progress: CGFloat    = 0
        var sourceIndex:Int      = 0
        var targetIndex:Int      = 0
        let scrollViewW =  CGFloat(frame.size.width)
        
        if startOffsetX > currentOffsetX { //右 小
            // 1.计算progress
            progress = 1 - (currentOffsetX / scrollViewW - floor(currentOffsetX / scrollViewW))
            // 2.计算targetIndex
            targetIndex = Int(currentOffsetX / scrollViewW)
            
            // 3.计算sourceIndex
            sourceIndex = targetIndex + 1
            if sourceIndex >= (childVCs?.count)! {
                sourceIndex = (childVCs?.count)! - 1
            }
        }else {//左大
            // 1.计算progress
            progress = currentOffsetX / scrollViewW - floor(currentOffsetX / scrollViewW)
            
            // 2.计算sourceIndex
            sourceIndex = Int(currentOffsetX / scrollViewW)
            
            // 3.计算targetIndex
            targetIndex = sourceIndex + 1
            if targetIndex >= (childVCs?.count)! {
                targetIndex = (childVCs?.count)! - 1
            }
            
            // 4.如果完全划过去
            if currentOffsetX - startOffsetX == scrollViewW {
                progress = 1
                targetIndex = sourceIndex
            }

        }
        delegate?.pageContentView(pageContentView: self, progress: progress, sourceIndex: sourceIndex, targetIndex: targetIndex)
//        print(" progress = \(progress) 开始 \(sourceIndex) 目标\(targetIndex)")
    }
}
//MARK: 对外暴露的方法
extension PageContentView {
    func setCurrentIndex(currentIndex:NSInteger) -> Void {
        let indetPath = IndexPath(item: currentIndex, section: 0)
        forbidDelegate = true
        collectionview.selectItem(at: indetPath, animated: false, scrollPosition: .centeredHorizontally)
    }
}