Corner radius on UIVisualEffectView

Question

Hi Im wondering if It's possible to set a corner radius on a UIVisualEffectView? Here's the code that i've tried:

@IBOutlet var blurView: UIVisualEffectView!

var blurLayer : CALayer{
    return blurView.layer
}
override func viewDidLoad() {
    super.viewDidLoad()
    setUpLayer()
    // Do any additional setup after loading the view.
}

func setUpLayer(){
    blurLayer.cornerRadius = 50
}

and

@IBOutlet var blurView: UIVisualEffectView!

override func viewDidLoad() {
    super.viewDidLoad()
    blurView.layer.cornerRadius = 50
    // Do any additional setup after loading the view.
}

Non of them works.

Answer 1

in storyboard add two parameter in user-defined runtime attributes layer.cornerRadius = 8 and layer.masksToBounds = true

or in code

@IBOutlet var blurView: UIVisualEffectView! {
    didSet {
        blurView.layer.cornerRadius = 8
        blurView.layer.masksToBounds = true
    }
}

Answer 2

All existed solutions are not perfect.

Since UIVisualEffectView implements its visual effects by compositing two subviews contents - one is a backdrop view and the other one is a filter view, when you implementing your corner radius by masking the whole UIVisualEffectView, there would be some dirty colors around corners.

To get rid of these dirty colors, you just need to mask UIVisualEffects's filter view.

private typealias ObjcRawUIVisualEffectViewSelCGRect =
    @convention(c) (UIVisualEffectView, Selector, CGRect) -> Void

private var cornerRadiusKey =
"com.WeZZard.Waxing.UIVisualEffectView-CornerRadius.cornerRadius"

private var needsUpdateMaskLayerKey =
"com.WeZZard.Waxing.UIVisualEffectView-CornerRadius.needsUpdateMaskLayer"

extension UIVisualEffectView {
    public var cornerRadius: CGFloat {
        get {
            if let storedValue = objc_getAssociatedObject(self,
                &cornerRadiusKey)
                as? CGFloat
            {
                return storedValue
            }
            return 0
        }
        set {
            if cornerRadius != newValue {
                objc_setAssociatedObject(self,
                    &cornerRadiusKey,
                    newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
                setNeedsUpdateMaskLayer()
            }
        }
    }

    private var needsUpdateMaskLayer: Bool {
        get {
            if let storedValue = objc_getAssociatedObject(self,
                &needsUpdateMaskLayerKey)
                as? Bool
            {
                return storedValue
            }
            return false
        }
        set {
            objc_setAssociatedObject(self,
                &needsUpdateMaskLayerKey,
                newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }


    public override class func initialize() {
        swizzle_setBounds()
    }

    private class func swizzle_setBounds() {
        struct Static {
            static var token: dispatch_once_t = 0
        }

        dispatch_once(&Static.token) {
            let selector: Selector = "setBounds:"

            let method = class_getInstanceMethod(self, selector)

            let imp_original = method_getImplementation(method)

            before_setBounds = unsafeBitCast(imp_original,
                ObjcRawUIVisualEffectViewSelCGRect.self)

            class_replaceMethod(self,
                selector,
                unsafeBitCast(after_setBounds, IMP.self),
                "@:{_struct=CGRect}")
        }
    }

    private func setNeedsUpdateMaskLayer() {
        needsUpdateMaskLayer = true
        NSOperationQueue.mainQueue().addOperationWithBlock { [weak self] _ in
            self?.updateMaskLayerIfNeeded()
        }
    }

    private func updateMaskLayerIfNeeded() {
        if needsUpdateMaskLayer {
            updateMaskLayer()
            needsUpdateMaskLayer = false
        }
    }

    private func updateMaskLayer(){
        var filterViewFound = false
        for each in subviews {
            if each.dynamicType.description()
                .containsString("Filter")
            {
                filterViewFound = true
                let newPath = UIBezierPath(roundedRect: each.bounds,
                    cornerRadius: self.cornerRadius)
                    .CGPath
                if let existedMask = each.layer.mask
                    as? CAShapeLayer
                {
                    existedMask.path = newPath
                } else {
                    let shapeLayer = CAShapeLayer()
                    shapeLayer.path = newPath
                    each.layer.mask = shapeLayer
                }
            } else {
                setNeedsUpdateMaskLayer()
            }
        }
        assert(filterViewFound == true, "Filter view was not found! Check your hacking!")
    }
}

private var before_setBounds: ObjcRawUIVisualEffectViewSelCGRect = { _ in
    fatalError("No implementation found")
}

private let after_setBounds: ObjcRawUIVisualEffectViewSelCGRect = {
    (aSelf, selector, bounds) -> Void in

    let oldBounds = aSelf.bounds

    before_setBounds(aSelf, selector, bounds)

    if oldBounds.size != bounds.size {
        aSelf.setNeedsUpdateMaskLayer()
    }
}

And all things done!

Answer 3

After @theMonster suggestion, I am posting what was a comment.

override func viewDidLoad() {
    super.viewDidLoad()
    blurView.layer.cornerRadius = 50
    blurView.clipsToBounds = true
}

Answer 4

Subclass UIVisualEffectView

class PSORoundedVisualEffectView : UIVisualEffectView{

    override func layoutSubviews() {
        super.layoutSubviews()
        updateMaskLayer()
    }

    func updateMaskLayer(){
        let shapeLayer = CAShapeLayer()
        shapeLayer.path = UIBezierPath(roundedRect: self.bounds, cornerRadius: 10).CGPath
        self.layer.mask = shapeLayer
    }
}

Replace the UIBezierPath with whatever shape you want.