varun04

let imageDecoder = DBImageDecoder()

var imageData = Data()

func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
    imageData.append(data)
    imageDecoder.setData(imageData, allDataReceived: false)
}

func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {

varun04

let task = urlSession.dataTask(with: url) { data, _, _ in
    guard let data = data else {
        return
    }
                    
    let imageDecoder = DBImageDecoder()
    imageDecoder.setData(data, allDataReceived: true)
                    
    guard let uiImage = imageDecoder.uiImage else {
        return

varun04

//
//  DBImageDecoder.swift
//  Test
//
//  Created by Varun Tomar on 03/08/21.
//

import ImageIO
import Foundation

varun04

//
//  DBImageDecoder+UIKit.swift
//  Test
//
//  Created by Varun Tomar on 04/08/21.
//

import UIKit

extension DBImageDecoder {

varun04

 func isFrameComplete(at index: Int) -> Bool {
        assert(frameCount > index)

        if index == frameCount - 1 {
            return CGImageSourceGetStatus(imageSource) == .statusComplete
        }

        return CGImageSourceGetStatusAtIndex(imageSource, index) == .statusComplete
 }

varun04

func createFrameImage(at index: Int, downsamplingLevel: DownSamplingLevel = .default, decodingOptions: DecodingOptions = .default) -> CGImage? {

        guard index < frameCount else {
            return nil
        }

        let image: CGImage?
        let options: CFDictionary

        switch decodingOptions.mode {

varun04

struct DecodingOptions {

        enum Mode {
            case synchronous
            case asynchronous
        }

        static var `default`: DecodingOptions {
            DecodingOptions(mode: .asynchronous, sizeForDrawing: nil)
        }

varun04

enum DownSamplingLevel: Int {
        case level0 = 1
        case level1 = 2
        case level2 = 4
        case level3 = 8
        public static var `default`: DownSamplingLevel {
            .level0
        }
}

varun04

private static let imageSourceOptions: [CFString: Any] = [
        kCGImageSourceShouldCache: true
]

private static let imageSourceAsyncOptions: [CFString: Any] = [
        kCGImageSourceShouldCacheImmediately: true,
        kCGImageSourceCreateThumbnailFromImageAlways: true
]

varun04

func frameSize(at index: Int, downsamplingLevel: DownSamplingLevel = .default) -> CGSize? {
        guard let properties = CGImageSourceCopyPropertiesAtIndex(imageSource, index, imageSourceOptions(with: downsamplingLevel)) as? [CFString: Any] else {
            return nil
        }

        guard let width = properties[kCGImagePropertyPixelWidth] as? Int, let height = properties[kCGImagePropertyPixelHeight] as? Int else {
            return nil
        }

        return CGSize(width: width, height: height)