Refactors loading operations to inherit from Roxas’ RSTLoadOperation

Delta.xcodeproj/project.pbxproj

@@ -47,7 +47,6 @@
 		BF3540081C5DAFAD00C1184C /* PauseTransitionCoordinator.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF3540071C5DAFAD00C1184C /* PauseTransitionCoordinator.swift */; };
 		BF59425C1E09BB810051894B /* Action.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942581E09BB810051894B /* Action.swift */; };
 		BF5942641E09BBB10051894B /* LoadControllerSkinImageOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942611E09BBB10051894B /* LoadControllerSkinImageOperation.swift */; };
-		BF5942651E09BBB10051894B /* LoadImageOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942621E09BBB10051894B /* LoadImageOperation.swift */; };
 		BF5942661E09BBB10051894B /* LoadImageURLOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942631E09BBB10051894B /* LoadImageURLOperation.swift */; };
 		BF59426A1E09BBD00051894B /* GridCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942681E09BBD00051894B /* GridCollectionViewCell.swift */; };
 		BF59426B1E09BBD00051894B /* GridCollectionViewLayout.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF5942691E09BBD00051894B /* GridCollectionViewLayout.swift */; };
@@ -153,7 +152,6 @@
 		BF3540071C5DAFAD00C1184C /* PauseTransitionCoordinator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = PauseTransitionCoordinator.swift; path = "Pause Menu/Segues/PauseTransitionCoordinator.swift"; sourceTree = "<group>"; };
 		BF5942581E09BB810051894B /* Action.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = Action.swift; path = Components/Action.swift; sourceTree = "<group>"; };
 		BF5942611E09BBB10051894B /* LoadControllerSkinImageOperation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = LoadControllerSkinImageOperation.swift; path = Components/Loading/LoadControllerSkinImageOperation.swift; sourceTree = "<group>"; };
-		BF5942621E09BBB10051894B /* LoadImageOperation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = LoadImageOperation.swift; path = Components/Loading/LoadImageOperation.swift; sourceTree = "<group>"; };
 		BF5942631E09BBB10051894B /* LoadImageURLOperation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = LoadImageURLOperation.swift; path = Components/Loading/LoadImageURLOperation.swift; sourceTree = "<group>"; };
 		BF5942681E09BBD00051894B /* GridCollectionViewCell.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = GridCollectionViewCell.swift; path = "Components/Collection View/GridCollectionViewCell.swift"; sourceTree = "<group>"; };
 		BF5942691E09BBD00051894B /* GridCollectionViewLayout.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = GridCollectionViewLayout.swift; path = "Components/Collection View/GridCollectionViewLayout.swift"; sourceTree = "<group>"; };
@@ -306,9 +304,8 @@
 		BF5942601E09BBA80051894B /* Loading */ = {
 			isa = PBXGroup;
 			children = (
-				BF5942611E09BBB10051894B /* LoadControllerSkinImageOperation.swift */,
-				BF5942621E09BBB10051894B /* LoadImageOperation.swift */,
 				BF5942631E09BBB10051894B /* LoadImageURLOperation.swift */,
+				BF5942611E09BBB10051894B /* LoadControllerSkinImageOperation.swift */,
 			);
 			name = Loading;
 			sourceTree = "<group>";
@@ -752,7 +749,6 @@
 				BF13A7561D5D29B0000BB055 /* PreviewGameViewController.swift in Sources */,
 				BF6866171DCAC8B900BF2D06 /* ControllerSkin+Configuring.swift in Sources */,
 				BF59427D1E09BC830051894B /* ControllerSkin.swift in Sources */,
-				BF5942651E09BBB10051894B /* LoadImageOperation.swift in Sources */,
 				BFCEA67E1D56FF640061A534 /* UIViewControllerContextTransitioning+Conveniences.swift in Sources */,
 				BF1173501DA32CF600047DF8 /* ControllersSettingsViewController.swift in Sources */,
 				BFFC461E1D59823500AF2CC6 /* GamesPresentationController.swift in Sources */,

Delta/Components/Loading/LoadControllerSkinImageOperation.swift

@@ -10,6 +10,17 @@ import UIKit
 
 import DeltaCore
 
+import Roxas
+
+extension LoadControllerSkinImageOperation
+{
+    enum Error: Swift.Error
+    {
+        case doesNotExist
+        case unsupportedTraits
+    }
+}
+
 class ControllerSkinImageCacheKey: NSObject
 {
     let controllerSkin: ControllerSkin
@@ -36,7 +47,7 @@ class ControllerSkinImageCacheKey: NSObject
     }
 }
 
-class LoadControllerSkinImageOperation: LoadImageOperation<ControllerSkinImageCacheKey>
+class LoadControllerSkinImageOperation: RSTLoadOperation<UIImage, ControllerSkinImageCacheKey>
 {
     let controllerSkin: ControllerSkin
     let traits: DeltaCore.ControllerSkin.Traits
@@ -52,9 +63,23 @@ class LoadControllerSkinImageOperation: LoadImageOperation<ControllerSkinImageCa
         super.init(cacheKey: cacheKey)
     }
     
-    override func loadImage() -> UIImage?
+    override func loadResult(completion: @escaping (UIImage?, Swift.Error?) -> Void)
     {
-        let image = self.controllerSkin.image(for: self.traits, preferredSize: self.size)
+        guard self.controllerSkin.supports(self.traits) else {
-        return image
+            completion(nil, Error.unsupportedTraits)
+            return
+        }
+        
+        guard let image = self.controllerSkin.image(for: self.traits, preferredSize: self.size) else {
+            completion(nil, Error.doesNotExist)
+            return
+        }
+        
+        // Force decompression of image
+        UIGraphicsBeginImageContextWithOptions(CGSize(width: 1, height: 1), true, 1.0)
+        image.draw(at: CGPoint.zero)
+        UIGraphicsEndImageContext()
+        
+        completion(image, nil)
     }
 }

Delta/Components/Loading/LoadImageOperation.swift

@@ -1,69 +0,0 @@
-//
-//  LoadImageOperation.swift
-//  Delta
-//
-//  Created by Riley Testut on 2/26/16.
-//  Copyright © 2016 Riley Testut. All rights reserved.
-//
-
-import Foundation
-import ImageIO
-
-import Roxas
-
-class LoadImageOperation<CacheKeyType: AnyObject>: RSTOperation
-{
-    var completionHandler: ((UIImage?) -> Void)? {
-        didSet {
-            self.completionBlock = {
-                rst_dispatch_sync_on_main_thread() {
-                    self.completionHandler?(self.image)
-                }
-            }
-        }
-    }
-    
-    var imageCache: NSCache<CacheKeyType, UIImage>? {
-        didSet {
-            // Ensures if an image is cached, it will be returned immediately, to prevent temporary flash of placeholder image
-            self.isImmediate = self.imageCache?.object(forKey: self.cacheKey) != nil
-        }
-    }
-    
-    private let cacheKey: CacheKeyType
-    private var image: UIImage?
-    
-    init(cacheKey: CacheKeyType)
-    {
-        self.cacheKey = cacheKey
-        
-        super.init()
-    }
-    
-    override func main()
-    {
-        guard !self.isCancelled else { return }
-        
-        if let cachedImage = self.imageCache?.object(forKey: self.cacheKey)
-        {
-            self.image = cachedImage
-            return
-        }
-        
-        guard let loadedImage = self.loadImage() else { return }
-        
-        // Force decompression of image
-        UIGraphicsBeginImageContextWithOptions(CGSize(width: 1, height: 1), true, 1.0)
-        loadedImage.draw(at: CGPoint.zero)
-        UIGraphicsEndImageContext()
-        
-        self.imageCache?.setObject(loadedImage, forKey: self.cacheKey)
-        
-        self.image = loadedImage
-    }
-    
-    func loadImage() -> UIImage?
-    {
-        return nil
-    }
-}

Delta/Components/Loading/LoadImageURLOperation.swift

@@ -9,25 +9,100 @@
 import UIKit
 import ImageIO
 
+import SDWebImage
+
 import Roxas
 
-class LoadImageURLOperation: LoadImageOperation<NSURL>
+extension LoadImageURLOperation
 {
-    public let url: URL
+    enum Error: Swift.Error
+    {
+        case doesNotExist
+        case invalid
+        case downloadFailed(Swift.Error)
+    }
+}
+
+class LoadImageURLOperation: RSTLoadOperation<UIImage, NSURL>
+{
+    let url: URL
+    
+    override var isAsynchronous: Bool {
+        return !self.url.isFileURL
+    }
+    
+    private var downloadOperation: SDWebImageOperation?
     
     init(url: URL)
     {
         self.url = url
+        
         super.init(cacheKey: url as NSURL)
     }
     
-    override func loadImage() -> UIImage?
+    override func cancel()
+    {
+        super.cancel()
+        
+        self.downloadOperation?.cancel()
+    }
+    
+    override func loadResult(completion: @escaping (UIImage?, Swift.Error?) -> Void)
+    {
+        let callback = { (image: UIImage?, error: Error?) in
+            
+            if let image = image, !self.isCancelled
+            {
+                // Force decompression of image
+                UIGraphicsBeginImageContextWithOptions(CGSize(width: 1, height: 1), true, 1.0)
+                image.draw(at: CGPoint.zero)
+                UIGraphicsEndImageContext()
+            }
+            
+            completion(image, error)
+        }
+        
+        if self.url.isFileURL
+        {
+            self.loadLocalImage(completion: callback)
+        }
+        else
+        {
+            self.loadRemoteImage(completion: callback)
+        }
+    }
+    
+    private func loadLocalImage(completion: @escaping (UIImage?, Error?) -> Void)
     {
         let options: NSDictionary = [kCGImageSourceShouldCache as NSString: true]
         
-        guard let imageSource = CGImageSourceCreateWithURL(self.url as CFURL, options), let quartzImage = CGImageSourceCreateImageAtIndex(imageSource, 0, options) else { return nil }
+        guard let imageSource = CGImageSourceCreateWithURL(self.url as CFURL, options) else {
+            completion(nil, .doesNotExist)
+            return
+        }
+        
+        guard let quartzImage = CGImageSourceCreateImageAtIndex(imageSource, 0, options) else {
+            completion(nil, .invalid)
+            return
+        }
         
         let image = UIImage(cgImage: quartzImage)
-        return image
+        completion(image, nil)
+    }
+    
+    private func loadRemoteImage(completion: @escaping (UIImage?, Error?) -> Void)
+    {
+        let manager = SDWebImageManager.shared()
+        
+        self.downloadOperation = manager?.downloadImage(with: self.url, options: [.retryFailed, .continueInBackground], progress: nil, completed: { (image, error, cacheType, finished, imageURL) in
+            if let error = error
+            {
+                completion(nil, .downloadFailed(error))
+            }
+            else
+            {
+                completion(image, nil)
+            }
+        })
     }
 }

Delta/Pause Menu/Save States/SaveStatesViewController.swift

@@ -236,8 +236,8 @@ private extension SaveStatesViewController
         if !ignoreOperations
         {
             let imageOperation = LoadImageURLOperation(url: saveState.imageFileURL)
-            imageOperation.imageCache = self.imageCache
+            imageOperation.resultsCache = self.imageCache
-            imageOperation.completionHandler = { image in
+            imageOperation.resultHandler = { (image, error) in
                 
                 if let image = image
                 {

Delta/Settings/Controller Skins/ControllerSkinsViewController.swift

@@ -95,8 +95,8 @@ private extension ControllerSkinsViewController
         let size = UIScreen.main.defaultControllerSkinSize
         
         let imageOperation = LoadControllerSkinImageOperation(controllerSkin: controllerSkin, traits: self.traits, size: size)
-        imageOperation.imageCache = self.imageCache
+        imageOperation.resultsCache = self.imageCache
-        imageOperation.completionHandler = { image in
+        imageOperation.resultHandler = { (image, error) in
             
             guard let image = image else { return }
             
@@ -159,7 +159,7 @@ extension ControllerSkinsViewController: UITableViewDataSourcePrefetching
             let size = UIScreen.main.defaultControllerSkinSize
             
             let imageOperation = LoadControllerSkinImageOperation(controllerSkin: controllerSkin, traits: self.traits, size: size)
-            imageOperation.imageCache = self.imageCache
+            imageOperation.resultsCache = self.imageCache
             
             self.imageOperationQueue.addOperation(imageOperation, forKey: indexPath as NSCopying)
         }

External/Roxas

@@ -1 +1 @@
-Subproject commit ecb29e0050fe9335845698c896c4cd8ce60df0da
+Subproject commit 0057bde6337f90b5747eec1baf94a1360e78c23e