In my app, I'm trying to implement a crop feature. So now I need to convert UIImageView's visible part to UIImage.
Here's a screenshot from the UI debugger.
I've tried to achieve it with this function, but it doesn't work.
func imageFromImageView(imageView: UIImageView) -> UIImage? {
UIGraphicsBeginImageContext(imageView.frame.size)
let context = UIGraphicsGetCurrentContext()!
context.rotate(by: 2 * .pi)
imageView.layer.render(in: context)
let image = UIGraphicsGetImageFromCurrentImageContext()
return image
}
You can use bellow extension:
private var rendererKey: UInt8 = 0
extension UIView {
var renderer: UIGraphicsImageRenderer! {
get {
guard let rendererInstance = objc_getAssociatedObject(self, &rendererKey) as? UIGraphicsImageRenderer else {
self.renderer = UIGraphicsImageRenderer(bounds: bounds)
return self.renderer
}
return rendererInstance
}
set(newValue) {
objc_setAssociatedObject(self, &rendererKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
}
}
func snapImageView() -> UIImageView {
let img:UIImage = renderer.image { ctx in
DispatchQueue.main.async {
layer.render(in: ctx.cgContext)
}
}
let imageView:UIImageView = UIImageView(image: img)
imageView.frame = renderer.format.bounds
imageView.clipsToBounds = true
return imageView
}
}
// Generate image and image view of any view instance
let anImageView = yourView.snapImageView()
Related
I'm having a very strange issue with transparent PNG files, sourced from the Photos app.
The issue is that I am writing an app that allows the user to bring up an instance of UIImagePickerController, where they select an image, and that image is then added to a UIImageView via its image property.
Pretty straightforward, eh? The issue is when the image in the library is a transparent PNG.
For whatever reason, whenever I try to render the image, it always has the background white.
As far as I can tell, the image is stored in the library as a transparent PNG. When I drag it out, and examine it with an image editor, it's fine. Just what I expect.
But when I extract it programmatically, it has a white background. I can't seem to get it to be transparent.
Here's the code that I use to extract the image (It's a picker callback):
func imagePickerController(_ inPicker: UIImagePickerController, didFinishPickingMediaWithInfo inInfo: [UIImagePickerController.InfoKey: Any]) {
let info = Dictionary(uniqueKeysWithValues: inInfo.map { key, value in (key.rawValue, value) })
guard let image = (info[UIImagePickerController.InfoKey.editedImage.rawValue] as? UIImage ?? info[UIImagePickerController.InfoKey.originalImage.rawValue] as? UIImage)?.resizeThisImage(toNewWidth: Self.maximumImageWidthAndHeightInPixels) else { return }
organization?.icon = image
inPicker.dismiss(animated: true) { DispatchQueue.main.async { [weak self] in
self?.imageButton?.image = image
self?.imageButton?.alpha = 1.0
self?.imageButton?.tintColor = self?.view.tintColor
self?.updateUI()
}
}
}
It's not actually a UIButton. It's a UIImageView, with an attached tap recognizer.
The resizeThisImage() method is in an extension that I wrote for UIImage. It works fine. I've been using it forever:
func resizeThisImage(toNewWidth inNewWidth: CGFloat? = nil, toNewHeight inNewHeight: CGFloat? = nil) -> UIImage? {
guard nil == inNewWidth,
nil == inNewHeight else {
var scaleX: CGFloat = (inNewWidth ?? size.width) / size.width
var scaleY: CGFloat = (inNewHeight ?? size.height) / size.height
scaleX = nil == inNewWidth ? scaleY : scaleX
scaleY = nil == inNewHeight ? scaleX : scaleY
let destinationSize = CGSize(width: size.width * scaleX, height: size.height * scaleY)
let destinationRect = CGRect(origin: .zero, size: destinationSize)
UIGraphicsBeginImageContextWithOptions(destinationSize, false, 0)
defer { UIGraphicsEndImageContext() } // This makes sure that we get rid of the offscreen context.
draw(in: destinationRect, blendMode: .normal, alpha: 1)
return UIGraphicsGetImageFromCurrentImageContext()
}
return nil
}
In any case, it happens whether or not I use the resizeThisImage() method. That's not the issue.
Does anyone have any ideas what may be causing the issue?
UPDATE: I implemented #DonMag 's example, and here's what I got:
Note that the generated "A" is surrounded by white.
I should note that I'm using a classic storyboard UIKit app (no scene stuff). I don't think that should be an issue, but I'm happy to provide my little sample app. I don't think it's worth creating a GH repo for.
There doesn't seem to be anything wrong with your code, so I have to wonder if your images really, truly have transparency?
Here's a simple example to check. It looks like this when run:
The code creates Red and Blue image views, with .contentMode = .center.
Tapping the "Create" button will generate a UIImage using SF Symbol -- green with transparent background, the size of the Red image view -- and save it to Photos in PNG format with transparency.
Tapping the "Load" button will bring up the image picker. Selecting an image (such as the one just created and saved) will load the image and - using your extension - resize it to 80 x 80 and assign it to the .image property of the Blue image view.
As you can see, the image loaded from the Photo Picker still has its transparency.
Your UIImage extension for resizing
extension UIImage {
func resizeThisImage(toNewWidth inNewWidth: CGFloat? = nil, toNewHeight inNewHeight: CGFloat? = nil) -> UIImage? {
guard nil == inNewWidth,
nil == inNewHeight else {
var scaleX: CGFloat = (inNewWidth ?? size.width) / size.width
var scaleY: CGFloat = (inNewHeight ?? size.height) / size.height
scaleX = nil == inNewWidth ? scaleY : scaleX
scaleY = nil == inNewHeight ? scaleX : scaleY
let destinationSize = CGSize(width: size.width * scaleX, height: size.height * scaleY)
let destinationRect = CGRect(origin: .zero, size: destinationSize)
UIGraphicsBeginImageContextWithOptions(destinationSize, false, 0)
defer { UIGraphicsEndImageContext() } // This makes sure that we get rid of the offscreen context.
draw(in: destinationRect, blendMode: .normal, alpha: 1)
return UIGraphicsGetImageFromCurrentImageContext()
}
return nil
}
}
UIImage extension to save to Photos in PNG format with transparency
extension UIImage {
// save to Photos in PNG format with transparency
func saveToPhotos(completion: #escaping (_ success:Bool) -> ()) {
if let pngData = self.pngData() {
PHPhotoLibrary.shared().performChanges({ () -> Void in
let creationRequest = PHAssetCreationRequest.forAsset()
let options = PHAssetResourceCreationOptions()
creationRequest.addResource(with: PHAssetResourceType.photo, data: pngData, options: options)
}, completionHandler: { (success, error) -> Void in
if success == false {
if let errorString = error?.localizedDescription {
print("Photo could not be saved: \(errorString))")
}
completion(false)
} else {
print("Photo saved!")
completion(true)
}
})
} else {
completion(false)
}
}
}
Example view controller uses (essentially) your func imagePickerController for loading a photo
class TestImageViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
var imgViewA: UIImageView = UIImageView()
var imgViewB: UIImageView = UIImageView()
override func viewDidLoad() {
super.viewDidLoad()
let vStack = UIStackView()
vStack.axis = .vertical
vStack.spacing = 20
let btnStack = UIStackView()
btnStack.axis = .horizontal
btnStack.distribution = .fillEqually
btnStack.spacing = 20
let btnCreate = UIButton()
let btnLoad = UIButton()
btnCreate.setTitle("Create", for: [])
btnLoad.setTitle("Load", for: [])
[btnCreate, btnLoad].forEach { b in
b.setTitleColor(.white, for: .normal)
b.setTitleColor(.lightGray, for: .highlighted)
b.backgroundColor = UIColor(red: 0.0, green: 0.5, blue: 0.75, alpha: 1.0)
btnStack.addArrangedSubview(b)
}
vStack.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(vStack)
[btnStack, imgViewA, imgViewB].forEach { v in
vStack.addArrangedSubview(v)
}
[imgViewA, imgViewB].forEach { v in
v.contentMode = .center
}
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
vStack.centerXAnchor.constraint(equalTo: g.centerXAnchor),
vStack.centerYAnchor.constraint(equalTo: g.centerYAnchor),
vStack.widthAnchor.constraint(equalToConstant: 200.0),
imgViewA.heightAnchor.constraint(equalTo: imgViewA.widthAnchor),
imgViewB.heightAnchor.constraint(equalTo: imgViewB.widthAnchor),
])
imgViewA.backgroundColor = .red
imgViewB.backgroundColor = .blue
btnCreate.addTarget(self, action: #selector(self.createAndSave(_:)), for: .touchUpInside)
btnLoad.addTarget(self, action: #selector(importPicture(_:)), for: .touchUpInside)
}
#objc func createAndSave(_ sender: Any) {
let w = imgViewA.frame.width
// create a Green image with transparent background
if let img = drawSystemImage("a.circle.fill", at: 80, centeredIn: CGSize(width: w, height: w)) {
imgViewA.image = img
// save it to Photos in PNG format with transparency
img.saveToPhotos { (success) in
if success {
// image saved to photos
print("saved")
}
else {
// image not saved
fatalError("save failed")
}
}
}
}
// create UIImage from SF Symbol system image
// at Point Size
// centered in CGSize
// will draw symbol in Green on transparent background
private func drawSystemImage(_ sysName: String, at pointSize: CGFloat, centeredIn size: CGSize) -> UIImage? {
let cfg = UIImage.SymbolConfiguration(pointSize: pointSize)
guard let img = UIImage(systemName: sysName, withConfiguration: cfg)?.withTintColor(.green, renderingMode: .alwaysOriginal) else { return nil }
let x = (size.width - img.size.width) * 0.5
let y = (size.height - img.size.height) * 0.5
let renderer = UIGraphicsImageRenderer(size: size)
return renderer.image { context in
img.draw(in: CGRect(origin: CGPoint(x: x, y: y), size: img.size))
}
}
#objc func importPicture(_ sender: Any) {
let picker = UIImagePickerController()
picker.allowsEditing = true
picker.delegate = self
present(picker, animated: true)
}
func imagePickerController(_ inPicker: UIImagePickerController, didFinishPickingMediaWithInfo inInfo: [UIImagePickerController.InfoKey: Any]) {
let info = Dictionary(uniqueKeysWithValues: inInfo.map { key, value in (key.rawValue, value) })
guard let image = (info[UIImagePickerController.InfoKey.editedImage.rawValue] as? UIImage ?? info[UIImagePickerController.InfoKey.originalImage.rawValue] as? UIImage)?.resizeThisImage(toNewWidth: 80) else { return }
// organization?.icon = image
inPicker.dismiss(animated: true) {
DispatchQueue.main.async { [weak self] in
self?.imgViewB.image = image
//self?.imageButton?.image = image
//self?.imageButton?.alpha = 1.0
//self?.imageButton?.tintColor = self?.view.tintColor
//self?.updateUI()
}
}
}
}
I am following a code example to make a blurred UILabel, https://stackoverflow.com/a/62224908/2226315.
My requirement is to make the label on blur after label initialization instead of calling the blur method at runtime. However, when I try to call blur after label gets initialized the value returned from UIGraphicsGetCurrentContext is nil hence having a "Fatal error: Unexpectedly found nil while unwrapping an Optional value"
UIGraphicsBeginImageContext(bounds.size)
print("DEBUG: bounds.size", bounds.size)
self.layer.render(in: UIGraphicsGetCurrentContext()!) // <- return nil
var image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
print("DEBUG: image image", image)
I tried adding the code in all the following places individually, the context can be fetched now however it does not generate the blur effect as expected.
override func layoutSubviews() {
super.layoutSubviews()
self.blur()
}
// OR
override func draw(_ rect: CGRect) {
super.draw(rect)
self.blur()
}
Full code snippet,
class BlurredLabel: UILabel {
func blur(_ blurRadius: Double = 2.5) {
let blurredImage = getBlurryImage(blurRadius)
let blurredImageView = UIImageView(image: blurredImage)
blurredImageView.translatesAutoresizingMaskIntoConstraints = false
blurredImageView.tag = 100
blurredImageView.contentMode = .center
blurredImageView.backgroundColor = .white
addSubview(blurredImageView)
NSLayoutConstraint.activate([
blurredImageView.centerXAnchor.constraint(equalTo: centerXAnchor),
blurredImageView.centerYAnchor.constraint(equalTo: centerYAnchor)
])
}
func unblur() {
subviews.forEach { subview in
if subview.tag == 100 {
subview.removeFromSuperview()
}
}
}
private func getBlurryImage(_ blurRadius: Double = 2.5) -> UIImage? {
UIGraphicsBeginImageContext(bounds.size)
layer.render(in: UIGraphicsGetCurrentContext()!)
guard let image = UIGraphicsGetImageFromCurrentImageContext(),
let blurFilter = CIFilter(name: "CIGaussianBlur") else {
UIGraphicsEndImageContext()
return nil
}
UIGraphicsEndImageContext()
blurFilter.setDefaults()
blurFilter.setValue(CIImage(image: image), forKey: kCIInputImageKey)
blurFilter.setValue(blurRadius, forKey: kCIInputRadiusKey)
var convertedImage: UIImage?
let context = CIContext(options: nil)
if let blurOutputImage = blurFilter.outputImage,
let cgImage = context.createCGImage(blurOutputImage, from: blurOutputImage.extent) {
convertedImage = UIImage(cgImage: cgImage)
}
return convertedImage
}
}
REFERENCE
Add blur view to label?
How to blur UILabel text
UPDATE
Usage based on "Eugene Dudnyk" answer
definitionLabel = BlurredLabel()
definitionLabel.numberOfLines = 0
definitionLabel.lineBreakMode = .byWordWrapping
definitionLabel.textColor = UIColor(named: "text")
definitionLabel.text = "Lorem Ipsum is simply dummy text"
definitionLabel.clipsToBounds = false
definitionLabel.isBluring = true
Here is a better solution - instead of retrieving the blurred image, just let the label blur itself.
When you need it to be blurred, set label.isBlurring = true.
Also, this solution is better for performance, because it reuses the same context and does not need the image view.
class BlurredLabel: UILabel {
var isBlurring = false {
didSet {
setNeedsDisplay()
}
}
var blurRadius: Double = 2.5 {
didSet {
blurFilter?.setValue(blurRadius, forKey: kCIInputRadiusKey)
}
}
lazy var blurFilter: CIFilter? = {
let blurFilter = CIFilter(name: "CIGaussianBlur")
blurFilter?.setDefaults()
blurFilter?.setValue(blurRadius, forKey: kCIInputRadiusKey)
return blurFilter
}()
override init(frame: CGRect) {
super.init(frame: frame)
layer.isOpaque = false
layer.needsDisplayOnBoundsChange = true
layer.contentsScale = UIScreen.main.scale
layer.contentsGravity = .center
isOpaque = false
isUserInteractionEnabled = false
contentMode = .redraw
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func display(_ layer: CALayer) {
let bounds = layer.bounds
guard !bounds.isEmpty && bounds.size.width < CGFloat(UINT16_MAX) else {
layer.contents = nil
return
}
UIGraphicsBeginImageContextWithOptions(layer.bounds.size, layer.isOpaque, layer.contentsScale)
if let ctx = UIGraphicsGetCurrentContext() {
self.layer.draw(in: ctx)
var image = UIGraphicsGetImageFromCurrentImageContext()?.cgImage
if isBlurring, let cgImage = image {
blurFilter?.setValue(CIImage(cgImage: cgImage), forKey: kCIInputImageKey)
let ciContext = CIContext(cgContext: ctx, options: nil)
if let blurOutputImage = blurFilter?.outputImage,
let cgImage = ciContext.createCGImage(blurOutputImage, from: blurOutputImage.extent) {
image = cgImage
}
}
layer.contents = image
}
UIGraphicsEndImageContext()
}
}
Transformed #EugeneDudnyk answer to UIView extension so it can be used also with TextView.
extension UIView {
struct BlurableKey {
static var blurable = "blurable"
}
func blur(radius: CGFloat) {
guard superview != nil else { return }
UIGraphicsBeginImageContextWithOptions(CGSize(width: frame.width, height: frame.height), false, 1)
layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
guard
let blur = CIFilter(name: "CIGaussianBlur"),
let image = image
else {
return
}
blur.setValue(CIImage(image: image), forKey: kCIInputImageKey)
blur.setValue(radius, forKey: kCIInputRadiusKey)
let ciContext = CIContext(options: nil)
let boundingRect = CGRect(
x:0,
y: 0,
width: frame.width,
height: frame.height
)
guard
let result = blur.value(forKey: kCIOutputImageKey) as? CIImage,
let cgImage = ciContext.createCGImage(result, from: boundingRect)
else {
return
}
let blurOverlay = UIImageView()
blurOverlay.frame = boundingRect
blurOverlay.image = UIImage(cgImage: cgImage)
blurOverlay.contentMode = .left
addSubview(blurOverlay)
objc_setAssociatedObject(
self,
&BlurableKey.blurable,
blurOverlay,
objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN
)
}
func unBlur() {
guard
let blurOverlay = objc_getAssociatedObject(self, &BlurableKey.blurable) as? UIImageView
else {
return
}
blurOverlay.removeFromSuperview()
objc_setAssociatedObject(
self,
&BlurableKey.blurable,
nil,
objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN
)
}
var isBlurred: Bool {
return objc_getAssociatedObject(self, &BlurableKey.blurable) is UIImageView
}
}
I refered to this question, and did add extension to UIView:
extension UIView {
// Using a function since `var image` might conflict with an existing variable
// (like on `UIImageView`)
func asImage() -> UIImage {
if #available(iOS 10.0, *) {
let renderer = UIGraphicsImageRenderer(bounds: bounds)
return renderer.image { rendererContext in
layer.render(in: rendererContext.cgContext)
}
} else {
UIGraphicsBeginImageContext(self.frame.size)
self.layer.render(in:UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return UIImage(cgImage: image!.cgImage!)
}
}
}
Then i create very simple test view:
private class FakeTestView: BaseView {
override func prepare() {
backgroundColor = .blue
setup()
}
private func setup(){
let lbl = LabelSL.regular()
lbl.text = "LabelSL.regular()"
addSubview(lbl)
lbl.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
lbl.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
}
}
That view showing correctly when treated as UIView.
Finally, i tried:
let newSlideFrame = CGRect(x: CGFloat(i) * event.expectedWidth(),
y: 0,
width: event.expectedWidth(),
height: frame.size.height)
let imgView = UIImageView()
imgView.contentMode = .scaleAspectFit
imgView.frame = newSlideFrame
imgView.image = FakeTestView().asImage()
scroll.addSubview(imgView)
But there is nothing showing. Code from above work when i try to add UIView, or UIImageView with sample images.
I want to take a snapshot from view including the status bar.
the code below works in the simulator but doesn't on a physical device.
extension UIScreen {
class func screenshot() -> UIImage {
let view = main.snapshotView(afterScreenUpdates: false)
UIGraphicsBeginImageContext(view.bounds.size)
view.drawHierarchy(in: view, afterScreenUpdates: true)
let screenshot = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return screenshot!
}
}
to fix your problem you can use this function:
func takeScreenshot() -> UIImage? {
var screenshotImage :UIImage?
let layer = UIApplication.shared.keyWindow!.layer
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);
guard let context = UIGraphicsGetCurrentContext() else {return nil}
layer.render(in:context)
screenshotImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return screenshotImage
}
I just tested this and it works on a physical device.
Create a extension like:
extension UIApplication {
func getViewScreenShot(vc: UIViewController) -> UIImage? {
let scale = UIScreen.main.scale
let bounds = vc.view.bounds
UIGraphicsBeginImageContextWithOptions(bounds.size, false, scale)
if UIGraphicsGetCurrentContext() != nil {
vc.view.drawHierarchy(in: bounds, afterScreenUpdates: true)
let screenshot = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return screenshot!
}
return nil
}
}
And call it like:
weak var weakSelf = self
let screenShotImage: UIImage = UIApplication.shared.getViewScreenShot(vc: weakSelf!)
How can I add a blur view to a label? The label is in front of a UIImage and I wanted the background of the label to be blurred, so that the user can read the text better. I get the Blur effect inside the bounds of the label, but the text itself disappears (maybe also gets blurred, idk why). I also tried to add a label programmatically, but I didn't get it working. I'm thankful for any kind of help!
let blur = UIBlurEffect(style: .Light)
let blurView = UIVisualEffectView(effect: blur)
blurView.frame = findATeamLabel.bounds
findATeamLabel.addSubview(blurView)
You can make your own BlurredLabel which can blur/unblur its text. Through a CoreImage blur filter you take the text of the label, blur it in an image, and display that image on top of the label.
class BlurredLabel: UILabel {
func blur(_ blurRadius: Double = 2.5) {
let blurredImage = getBlurryImage(blurRadius)
let blurredImageView = UIImageView(image: blurredImage)
blurredImageView.translatesAutoresizingMaskIntoConstraints = false
blurredImageView.tag = 100
blurredImageView.contentMode = .center
blurredImageView.backgroundColor = .white
addSubview(blurredImageView)
NSLayoutConstraint.activate([
blurredImageView.centerXAnchor.constraint(equalTo: centerXAnchor),
blurredImageView.centerYAnchor.constraint(equalTo: centerYAnchor)
])
}
func unblur() {
subviews.forEach { subview in
if subview.tag == 100 {
subview.removeFromSuperview()
}
}
}
private func getBlurryImage(_ blurRadius: Double = 2.5) -> UIImage? {
UIGraphicsBeginImageContext(bounds.size)
layer.render(in: UIGraphicsGetCurrentContext()!)
guard let image = UIGraphicsGetImageFromCurrentImageContext(),
let blurFilter = CIFilter(name: "CIGaussianBlur") else {
UIGraphicsEndImageContext()
return nil
}
UIGraphicsEndImageContext()
blurFilter.setDefaults()
blurFilter.setValue(CIImage(image: image), forKey: kCIInputImageKey)
blurFilter.setValue(blurRadius, forKey: kCIInputRadiusKey)
var convertedImage: UIImage?
let context = CIContext(options: nil)
if let blurOutputImage = blurFilter.outputImage,
let cgImage = context.createCGImage(blurOutputImage, from: blurOutputImage.extent) {
convertedImage = UIImage(cgImage: cgImage)
}
return convertedImage
}
}
PS: Please make sure to improve this component as of your requirements (for example avoid blurring if already blurred or you could remove the current blurred and apply the blurred again if text has changed).
PSPS: Take into consideration also that applying blur to something makes its content bleeds out, so either set clipsToBounds = false to the BlurredLabel or find out other way to accomplish your visual effect in order to avoid the blurred image looks like is not in same position as the label unblurred text that was previously.
To use it you can simply create a BlurredLabel:
let blurredLabel = BlurredLabel()
blurredLabel.text = "56.00 €"
And on some button tap maybe you could achieve blurring as of blurredLabel.blur() and unblurring as of blurredLabel.unblur().
This is the output achieved with blur() through a blurRadius of 2.5:
To read more about Gaussian Blur, there is a good article on Wikipedia: https://en.wikipedia.org/wiki/Gaussian_blur
You could try sending it to the back of the view hierarchy for the label. Try
findATeamLabel.sendSubviewToBack(blurView)
Swift 5 - Blur as UIView extension
extension UIView {
struct BlurableKey {
static var blurable = "blurable"
}
func blur(radius: CGFloat) {
guard superview != nil else { return }
UIGraphicsBeginImageContextWithOptions(CGSize(width: frame.width, height: frame.height), false, 1)
layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
guard
let blur = CIFilter(name: "CIGaussianBlur"),
let image = image
else {
return
}
blur.setValue(CIImage(image: image), forKey: kCIInputImageKey)
blur.setValue(radius, forKey: kCIInputRadiusKey)
let ciContext = CIContext(options: nil)
let boundingRect = CGRect(
x:0,
y: 0,
width: frame.width,
height: frame.height
)
guard
let result = blur.value(forKey: kCIOutputImageKey) as? CIImage,
let cgImage = ciContext.createCGImage(result, from: boundingRect)
else {
return
}
let blurOverlay = UIImageView()
blurOverlay.frame = boundingRect
blurOverlay.image = UIImage(cgImage: cgImage)
blurOverlay.contentMode = .left
addSubview(blurOverlay)
objc_setAssociatedObject(
self,
&BlurableKey.blurable,
blurOverlay,
objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN
)
}
func unBlur() {
guard
let blurOverlay = objc_getAssociatedObject(self, &BlurableKey.blurable) as? UIImageView
else {
return
}
blurOverlay.removeFromSuperview()
objc_setAssociatedObject(
self,
&BlurableKey.blurable,
nil,
objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN
)
}
var isBlurred: Bool {
return objc_getAssociatedObject(self, &BlurableKey.blurable) is UIImageView
}
}
I got it working by adding just a View behind the label (the label is NOT inside that view, just in front of it). Then I added the blur effect to the view... I still think there should be an easier way.
None of the answers worked for me, the accepted answer dont work with background of different color of white, or label color different of black based on the comments it goes to another question yet the answer made the blur move to the right a lot. So after some reading adjusting the CGRect on the result image.
class BlurredLabel: UILabel {
var isBlurring = false {
didSet {
setNeedsDisplay()
}
}
var blurRadius: Double = 8 {
didSet {
blurFilter?.setValue(blurRadius, forKey: kCIInputRadiusKey)
}
}
lazy var blurFilter: CIFilter? = {
let blurFilter = CIFilter(name: "CIGaussianBlur")
blurFilter?.setDefaults()
blurFilter?.setValue(blurRadius, forKey: kCIInputRadiusKey)
return blurFilter
}()
override init(frame: CGRect) {
super.init(frame: frame)
layer.isOpaque = false
layer.needsDisplayOnBoundsChange = true
layer.contentsScale = UIScreen.main.scale
layer.contentsGravity = .center
isOpaque = false
isUserInteractionEnabled = false
contentMode = .redraw
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
override func display(_ layer: CALayer) {
let bounds = layer.bounds
guard !bounds.isEmpty && bounds.size.width < CGFloat(UINT16_MAX) else {
layer.contents = nil
return
}
UIGraphicsBeginImageContextWithOptions(layer.bounds.size, layer.isOpaque, layer.contentsScale)
if let ctx = UIGraphicsGetCurrentContext() {
self.layer.draw(in: ctx)
var image = UIGraphicsGetImageFromCurrentImageContext()?.cgImage
if isBlurring {
blurFilter?.setValue(CIImage(cgImage: image!), forKey: kCIInputImageKey)
let ciContext = CIContext(cgContext: ctx, options: nil)
if let blurOutputImage = blurFilter?.outputImage {
let boundingRect = CGRect(
x:0,
y: blurOutputImage.extent.minY,
width: blurOutputImage.extent.width,
height: blurOutputImage.extent.height
)
image = ciContext.createCGImage(blurOutputImage, from: boundingRect)
}
}
layer.contents = image
}
UIGraphicsEndImageContext()
}
}