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iosswiftcgaffinetransform

CGAffineTransform over other view


There are nine subviews in my view. (topLeft, top, topRight, left, center, right, bottomLeft, bottom, bottomRight). When I do the animation with CGAffineTransform in the center subview.

This is a tricky question. Subviews top to the center will be covered; the others will not be covered. Why?

How can I do to cover all subviews in my animation?

origin problem expected

    override func viewDidLoad() {
        super.viewDidLoad()

        let top = UIView()
        top.backgroundColor = .red
        top.frame = CGRect(x: self.view.frame.width/2, y: self.view.frame.height/2, width: 20, height: 20)
        top.layer.masksToBounds = true
        view.addSubview(top)

        let topLeft = UIView()
        topLeft.backgroundColor = .orange
        topLeft.frame = CGRect(x: self.view.frame.width/2 - 20, y: self.view.frame.height/2, width: 20, height: 20)
        topLeft.layer.masksToBounds = true
        view.addSubview(topLeft)

        let topRight = UIView()
        topRight.backgroundColor = .gray
        topRight.frame = CGRect(x: self.view.frame.width/2 + 20, y: self.view.frame.height/2, width: 20, height: 20)
        topRight.layer.masksToBounds = true
        view.addSubview(topRight)

        let center = UIView()
        center.backgroundColor = .black
        center.frame = CGRect(x: self.view.frame.width/2, y: self.view.frame.height/2 + 20, width: 20, height: 20)
        view.addSubview(center)

        let left = UIView()
        left.backgroundColor = .cyan
        left.frame = CGRect(x: self.view.frame.width/2 - 20, y: self.view.frame.height/2 + 20, width: 20, height: 20)
        view.addSubview(left)

        let right = UIView()
        right.backgroundColor = .brown
        right.frame = CGRect(x: self.view.frame.width/2 + 20, y: self.view.frame.height/2 + 20 , width: 20, height: 20)
        view.addSubview(right)

        let bottom = UIView()
        bottom.backgroundColor = .yellow
        bottom.frame = CGRect(x: self.view.frame.width/2 , y: self.view.frame.height/2 + 20 + 20, width: 20, height: 20)
        view.addSubview(bottom)

        let bottomLeft = UIView()
        bottomLeft.backgroundColor = .magenta
        bottomLeft.frame = CGRect(x: self.view.frame.width/2 - 20, y: self.view.frame.height/2 + 20 + 20, width: 20, height: 20)
        view.addSubview(bottomLeft)


        let bottomRight = UIView()
        bottomRight.backgroundColor = .green
        bottomRight.frame = CGRect(x: self.view.frame.width/2 + 20, y: self.view.frame.height/2 + 20 + 20, width: 20, height: 20)
        view.addSubview(bottomRight)

        view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTap)))

    }

    func handleTap(gesture: UITapGestureRecognizer) {
        let location = gesture.location(in: view)
        for subview in view.subviews {
            if subview.frame.contains(location) {
                let scaleUp = CGAffineTransform(scaleX: 3, y: 3)

                UIView.animate(withDuration: 0.5, animations: {
                    subview.transform = scaleUp
                }) { (success: Bool) in
                //subview.transform = .identity
                }
            }
        }
    }

Solution

  • bringSubviewToFront before applying the transform. It will be above all other subviews and will cover them.