I’d like to create an animated GIF in SwiftUI.
I tried:
Image(“myGif”)ImageNone of the above worked, has anyone figured this out?
You can do it by creating UIViewRepresentable from UIView.
UIViewRepresentable create View for you, which you can use it in SwiftUI class.
Step1: Create UIView class for Gifview
class GIFPlayerView: UIView {
private let imageView = UIImageView()
convenience init(gifName: String) {
self.init()
let gif = UIImage.gif(asset: gifName)
imageView.image = gif
imageView.contentMode = .scaleAspectFit
self.addSubview(imageView)
}
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
imageView.frame = bounds
}
}
Step2: Create UIViewRepresentable class for GifView
struct GIFView: UIViewRepresentable {
var gifName: String
func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<GIFView>) {
}
func makeUIView(context: Context) -> UIView {
return GIFPlayerView(gifName: gifName)
}
}
Step3: Use that UIViewRepresentable view.
var body: some View {
VStack {
GIFView(gifName: "your gif name")
}
}
Note: Extension for Gif to Image. Refer: https://stackoverflow.com/a/45554784
extension UIImageView {
public func loadGif(name: String) {
DispatchQueue.global().async {
let image = UIImage.gif(name: name)
DispatchQueue.main.async {
self.image = image
}
}
}
@available(iOS 9.0, *)
public func loadGif(asset: String) {
DispatchQueue.global().async {
let image = UIImage.gif(asset: asset)
DispatchQueue.main.async {
self.image = image
}
}
}
}
extension UIImage {
public class func gif(data: Data) -> UIImage? {
// Create source from data
guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {
print("SwiftGif: Source for the image does not exist")
return nil
}
return UIImage.animatedImageWithSource(source)
}
public class func gif(url: String) -> UIImage? {
// Validate URL
guard let bundleURL = URL(string: url) else {
print("SwiftGif: This image named \"\(url)\" does not exist")
return nil
}
// Validate data
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(url)\" into NSData")
return nil
}
return gif(data: imageData)
}
public class func gif(name: String) -> UIImage? {
// Check for existance of gif
guard let bundleURL = Bundle.main
.url(forResource: name, withExtension: "gif") else {
print("SwiftGif: This image named \"\(name)\" does not exist")
return nil
}
// Validate data
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")
return nil
}
return gif(data: imageData)
}
@available(iOS 9.0, *)
public class func gif(asset: String) -> UIImage? {
// Create source from assets catalog
guard let dataAsset = NSDataAsset(name: asset) else {
print("SwiftGif: Cannot turn image named \"\(asset)\" into NSDataAsset")
return nil
}
return gif(data: dataAsset.data)
}
internal class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {
var delay = 0.1
// Get dictionaries
let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)
let gifPropertiesPointer = UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 0)
defer {
gifPropertiesPointer.deallocate()
}
let unsafePointer = Unmanaged.passUnretained(kCGImagePropertyGIFDictionary).toOpaque()
if CFDictionaryGetValueIfPresent(cfProperties, unsafePointer, gifPropertiesPointer) == false {
return delay
}
let gifProperties: CFDictionary = unsafeBitCast(gifPropertiesPointer.pointee, to: CFDictionary.self)
// Get delay time
var delayObject: AnyObject = unsafeBitCast(
CFDictionaryGetValue(gifProperties,
Unmanaged.passUnretained(kCGImagePropertyGIFUnclampedDelayTime).toOpaque()),
to: AnyObject.self)
if delayObject.doubleValue == 0 {
delayObject = unsafeBitCast(CFDictionaryGetValue(gifProperties,
Unmanaged.passUnretained(kCGImagePropertyGIFDelayTime).toOpaque()), to: AnyObject.self)
}
if let delayObject = delayObject as? Double, delayObject > 0 {
delay = delayObject
} else {
delay = 0.1 // Make sure they're not too fast
}
return delay
}
internal class func gcdForPair(_ lhs: Int?, _ rhs: Int?) -> Int {
var lhs = lhs
var rhs = rhs
// Check if one of them is nil
if rhs == nil || lhs == nil {
if rhs != nil {
return rhs!
} else if lhs != nil {
return lhs!
} else {
return 0
}
}
// Swap for modulo
if lhs! < rhs! {
let ctp = lhs
lhs = rhs
rhs = ctp
}
// Get greatest common divisor
var rest: Int
while true {
rest = lhs! % rhs!
if rest == 0 {
return rhs! // Found it
} else {
lhs = rhs
rhs = rest
}
}
}
internal class func gcdForArray(_ array: [Int]) -> Int {
if array.isEmpty {
return 1
}
var gcd = array[0]
for val in array {
gcd = UIImage.gcdForPair(val, gcd)
}
return gcd
}
internal class func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {
let count = CGImageSourceGetCount(source)
var images = [CGImage]()
var delays = [Int]()
// Fill arrays
for index in 0..<count {
// Add image
if let image = CGImageSourceCreateImageAtIndex(source, index, nil) {
images.append(image)
}
// At it's delay in cs
let delaySeconds = UIImage.delayForImageAtIndex(Int(index),
source: source)
delays.append(Int(delaySeconds * 1000.0)) // Seconds to ms
}
// Calculate full duration
let duration: Int = {
var sum = 0
for val: Int in delays {
sum += val
}
return sum
}()
// Get frames
let gcd = gcdForArray(delays)
var frames = [UIImage]()
var frame: UIImage
var frameCount: Int
for index in 0..<count {
frame = UIImage(cgImage: images[Int(index)])
frameCount = Int(delays[Int(index)] / gcd)
for _ in 0..<frameCount {
frames.append(frame)
}
}
// Heyhey
let animation = UIImage.animatedImage(with: frames,
duration: Double(duration) / 1000.0)
return animation
}
}
