swift-商品加入购物车动画

// MARK: - 商品图片抛入购物车的动画效果 
extension QHGoodListViewController {
    /**
    开始动画 
    - parameter rect: 商品图标对象的frame 
    - parameter iconView: 商品图标对象
    */
    
    private func startAnimation(rect: CGRect,iconView:UIImageView) {
        
        if layer == nil {
            layer = CALayer()
            layer?.contents = iconView.layer.contents
            layer?.contentsGravity = kCAGravityResizeAspectFill
            layer?.bounds = rect
            layer?.cornerRadius = CGRectGetHeight(layer!.bounds)*0.5
            layer?.masksToBounds = true
            layer?.position = CGPoint(x: iconView.center.x,y: CGRectGetMinY(rect)+96)
                UIApplication.sharedApplication().keyWindow?.layer.addSublayer(layer!)
            path = UIBezierPath()
            path!.movetoPoint(layer!.position)
            path?.addQuadCurvetoPoint(CGPoint(x: SCREEN_WIDTH - 25,y: 35),controlPoint: CGPoint(x: SCREEN_WIDTH*0.5,y: rect.origin.y - 80))
        }
        
        // 组动画
        groupAnimation()
    }
    
    // 组动画 帧动画抛入购物车 并放大、缩小图层增加点动效
    private func groupAnimation() {
        
        // 开始动画禁用tableView交互 
        tableView.userInteractionEnabled = false
        
        // 帧动画
        let animation = CAKeyframeAnimation(keyPath: "position")
        animation.path = path!.CGPath
        animation.rotationMode = kCAAnimationRotateAuto
        
        // 放大动画 
        let bigAnimation = CABasicAnimation(keyPath: "transform.scale")
        bigAnimation.duration = 0.5
        bigAnimation.fromValue = 1
        bigAnimation.tovalue = 2
        bigAnimation.timingFunction = camediatimingFunction(name: kcamediatimingFunctionEaseIn)
        
        // 缩小动画
        let smallAnimation = CABasicAnimation(keyPath: "transform.scale")
        smallAnimation.beginTime = 0.5
        smallAnimation.duration = 1.5
        smallAnimation.fromValue = 2
        smallAnimation.tovalue = 0.3
        smallAnimation.timingFunction = camediatimingFunction(name: kcamediatimingFunctionEaSEOut)
        
        // 组动画
        let groupAnimation = CAAnimationGroup()
        groupAnimation.animations = [animation,bigAnimation,smallAnimation]
        groupAnimation.duration = 2
        groupAnimation.removedOnCompletion = false
        groupAnimation.fillMode = kCAFillModeForwards
        groupAnimation.delegate = self
        layer?.addAnimation(groupAnimation,forKey: "groupAnimation")
    }
    
    // 动画结束后做一些操作 
    override func animationDidStop(anim: CAAnimation,finished flag: Bool) {
        
        // 如果动画是我们的组动画 才开始一些操作 
        if anim == layer?.animationForKey("groupAnimation") {
            
            // 开启交互 
            tableView.userInteractionEnabled = true
            
            // 隐藏图层 
            layer?.removeAllAnimations()
            layer?.removeFromSuperlayer()
            layer = nil
            
            // 如果商品数大于0 显示购物车里地商品数量 
            if self.addGoodArray.count > 0 {
                addCountLabel.hidden = false
            }
            
            // 商品数量渐出 
            let goodCountAnimation = CATransition()
            goodCountAnimation.duration = 0.25
            addCountLabel.text = "\(self.addGoodArray.count)"
            addCountLabel.layer.addAnimation(goodCountAnimation,forKey: nil)
            
            //购物车颤抖 
            let cartAnimation = CABasicAnimation(keyPath: "transform.translation.y")
            cartAnimation.duration = 0.25
            cartAnimation.fromValue = -5
            cartAnimation.tovalue = 5
            cartAnimation.autoreverses = true
            cartButton.layer.addAnimation(cartAnimation,forKey: nil)
        }
    }
    
    
}