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//
// iOSDevCenters+GIF.swift
// GIF-Swift
//
// Created by iOSDevCenters on 11/12/15.
// Copyright © 2016 iOSDevCenters. All rights reserved.
//
import UIKit
import ImageIO
// FIXME: comparison operators with optionals were removed from the Swift Standard Libary.
// Consider refactoring the code to use the non-optional operators.
fileprivate func < <T : Comparable>(lhs: T?, rhs: T?) -> Bool {
switch (lhs, rhs) {
case let (l?, r?):
return l < r
case (nil, _?):
return true
default:
return false
}
}
extension UIImage {
public class func gifImageWithData(_ data: Data) -> UIImage? {
guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {
print("image doesn't exist")
return nil
}
return UIImage.animatedImageWithSource(source)
}
public class func gifImageWithURL(_ gifUrl:String) -> UIImage? {
guard let bundleURL:URL? = URL(string: gifUrl)
else {
print("image named \"\(gifUrl)\" doesn't exist")
return nil
}
guard let imageData = try? Data(contentsOf: bundleURL!) else {
print("image named \"\(gifUrl)\" into NSData")
return nil
}
return gifImageWithData(imageData)
}
public class func gifImageWithName(_ name: String) -> UIImage? {
guard let bundleURL = Bundle.main
.url(forResource: name, withExtension: "gif") else {
print("SwiftGif: This image named \"\(name)\" does not exist")
return nil
}
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")
return nil
}
return gifImageWithData(imageData)
}
class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {
var delay = 0.1
let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)
let gifProperties: CFDictionary = unsafeBitCast(
CFDictionaryGetValue(cfProperties,
Unmanaged.passUnretained(kCGImagePropertyGIFDictionary).toOpaque()),
to: CFDictionary.self)
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)
}
delay = delayObject as! Double
if delay < 0.1 {
delay = 0.1
}
return delay
}
class func gcdForPair(_ a: Int?, _ b: Int?) -> Int {
var a = a
var b = b
if b == nil || a == nil {
if b != nil {
return b!
} else if a != nil {
return a!
} else {
return 0
}
}
if a < b {
let c = a
a = b
b = c
}
var rest: Int
while true {
rest = a! % b!
if rest == 0 {
return b!
} else {
a = b
b = rest
}
}
}
class func gcdForArray(_ array: Array<Int>) -> Int {
if array.isEmpty {
return 1
}
var gcd = array[0]
for val in array {
gcd = UIImage.gcdForPair(val, gcd)
}
return gcd
}
class func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {
let count = CGImageSourceGetCount(source)
var images = [CGImage]()
var delays = [Int]()
for i in 0..<count {
if let image = CGImageSourceCreateImageAtIndex(source, i, nil) {
images.append(image)
}
let delaySeconds = UIImage.delayForImageAtIndex(Int(i),
source: source)
delays.append(Int(delaySeconds * 1000.0)) // Seconds to ms
}
let duration: Int = {
var sum = 0
for val: Int in delays {
sum += val
}
return sum
}()
let gcd = gcdForArray(delays)
var frames = [UIImage]()
var frame: UIImage
var frameCount: Int
for i in 0..<count {
frame = UIImage(cgImage: images[Int(i)])
frameCount = Int(delays[Int(i)] / gcd)
for _ in 0..<frameCount {
frames.append(frame)
}
}
let animation = UIImage.animatedImage(with: frames,
duration: Double(duration) / 1000.0)
return animation
}
}
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