相信大家都有用过了，业余时间模仿了一下

• 浮窗的移动、隐藏

  
  
  显示、移动、移除部分

进入页面，显示，隐藏浮窗

正文

思想：把整个功能拆分为三个部分：

• 1、浮窗按钮： UIButton
  这个按钮为浮窗功能的核心，主要包括: 通过touch系列事件处理移动浮窗、进入二级页面、隐藏浮窗
• 2、取消浮窗： UIView
  这个View就是用来显示交互的，构成为一个Button和CAShapeLayer
• 3、一个Controller 用于显示内容
  这个就是内容的显示，其中包括了：自定义转场动画、浮窗的显示/隐藏逻辑。

一、 Button 的实现

主要就是监听三个方法：touchBegan,touchesMoved,touchesEnded

• touchesMoved
  ①：中核心操作就是把当前的点转化为在父视图中的点

        guard let touch = touches.first, let superView = self.superview else { return }
        let point = touch.location(in: superView)
 
        self.frame.origin.x = point.x - frame.width * 0.5
        self.frame.origin.y = point.y - frame.height * 0.5

②：隐藏浮窗View的显示

// show hide floating window view
        UIView.animate(withDuration: 0.2) {
            hideWindowView.frame.origin = CGPoint(x: UIScreen.main.bounds.width - hideWindowView.frame.width, y: UIScreen.main.bounds.height - hideWindowView.frame.height)
            hideWindowView.moreRedBackground(isHiddenBtn)
        }

• touchesEnded 中核心操作
  ①：修改按钮的x坐标

        let currentPointX = frame.origin.x + frame.width * 0.5
        let screenW = UIScreen.main.bounds.width
        
        let pointX = (currentPointX > screenW * 0.5) ? (screenW - frame.width) - margin : margin

②：判断是否移动了，如果没移动就触发进入浮窗方法

        guard let touch = touches.first, let superView = superview else { return }
        
        if lastPoint == touch.location(in: superView) { //push
            let controller = UIApplication.shared.keyWindow?.rootViewController
            var nav = controller?.navigationController
            if nav == nil {
                nav = controller?.childViewControllers.first?.navigationController
            }
            
            nav?.pushViewController(fwController, animated: true)
            return
        }

③：隐藏浮窗和浮窗按钮的显示与隐藏

// show hide floating window view
        UIView.animate(withDuration: 0.2) {
            hideWindowView.frame.origin = CGPoint(x: UIScreen.main.bounds.width, y: UIScreen.main.bounds.height)
            self.isHidden = isHiddenBtn
        }

二、隐藏浮窗View的实现

①：Button 通过titleEdgeInsets和imageEdgeInsets来自定义布局

//自定义按钮
class PQButton: UIButton {
    
    convenience init(_ textLayout: EIQMenuTextLayout){
        self.init(frame: .zero)
        self.textLayout = textLayout
    }
    
    enum EIQMenuTextLayout: Int {
        case top,left,bottom,right
    }
    public var spacing: CGFloat = 20
    public var textLayout: EIQMenuTextLayout = .right
    override func layoutSubviews() {
        super.layoutSubviews()
        
        
        guard let title = self.titleLabel?.text as NSString?, let titleFont = self.titleLabel?.font else { return }
        
        let imageSize = self.imageRect(forContentRect: self.frame)
        
        let titleSize = title.size(withAttributes: [NSAttributedStringKey.font : titleFont])
        
        var titleInsets: UIEdgeInsets = self.titleEdgeInsets
        var imageInsets: UIEdgeInsets = self.imageEdgeInsets
        switch textLayout {
        case .left:
            titleInsets = UIEdgeInsets(top: 0, left: -(imageSize.width * 2), bottom: 0, right: 0)
            imageInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0,
                                       right: -(titleSize.width * 2 + spacing))
        case .top:
            titleInsets = UIEdgeInsets(top: -(imageSize.height + titleSize.height + spacing),
                                       left: -(imageSize.width), bottom: 0, right: 0)
            imageInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: -titleSize.width)
        case .bottom:
            titleInsets = UIEdgeInsets(top: (imageSize.height + titleSize.height + spacing),
                                       left: -(imageSize.width), bottom: 0, right: 0)
            imageInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: -titleSize.width)
        default:
            break
        }
        
        self.titleEdgeInsets = titleInsets
        self.imageEdgeInsets = imageInsets
    }
}

②：通过view.layer.mask 去实现

创建CAShapeLayer

private lazy var maskLayer: CAShapeLayer = {
        let layer = CAShapeLayer()
        layer.frame = self.bounds
        self.layer.mask = layer
        return layer
    }()

设置path

public func moreRedBackground(_ more: Bool){
        var radius = frame.width
        if more {
            radius += 5
        }
        let path = UIBezierPath(arcCenter: CGPoint(x: frame.width + 10, y: frame.height + 10), radius: radius, startAngle: 0, endAngle: CGFloat(Double.pi * 2), clockwise: false)
        maskLayer.path = path.cgPath
    }

三、Controller的实现

只是实现Controller就没什么好说的，这里主要说的是转场动画部分

• 第一步：实现代理

navigationController?.delegate = self

• 第二步：实现代理协议方法
  这个代理方法中如果返回了 nil ，即表示使用系统自带的pop、push效果

func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        
        if operation == .push {
            return TransitionAnimator(isPush: true, animation: .overlay)
        }
        
        if operation == .pop && !fwBtnIsHidden {
            return TransitionAnimator(isPush: false, animation: .overlay)
        }
        
        return nil
    }

ps：如果想实现交互式处理需要实现另外一个方法, 在该方法中返回处理对象

@available(iOS 7.0, *)
    optional public func navigationController(_ navigationController: UINavigationController, interactionControllerFor animationController: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning?

UIViewControllerAnimatedTransitioning协议介绍：

    返回动画时长
    public func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval

   动画具体处理  containerView为内容视图，所有显示的内容均要添加进去方可显示
    public func animateTransition(using transitionContext: UIViewControllerContextTransitioning)

更多详细,请看Demo