The first draft of ImageCompressionStrategy

MyApp.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		9A135C032CBE774500808EB3 /* ImageProcessor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9A135C022CBE774300808EB3 /* ImageProcessor.swift */; };
 		9AAC417C2C74668B00AC0A60 /* MyApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9AAC417B2C74668B00AC0A60 /* MyApp.swift */; };
 		9AAC417E2C74668B00AC0A60 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9AAC417D2C74668B00AC0A60 /* ContentView.swift */; };
 		9AAC41802C74668C00AC0A60 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 9AAC417F2C74668C00AC0A60 /* Assets.xcassets */; };
@@ -15,6 +16,7 @@
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
+		9A135C022CBE774300808EB3 /* ImageProcessor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ImageProcessor.swift; sourceTree = "<group>"; };
 		9AAC41782C74668B00AC0A60 /* MyApp.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = MyApp.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		9AAC417B2C74668B00AC0A60 /* MyApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MyApp.swift; sourceTree = "<group>"; };
 		9AAC417D2C74668B00AC0A60 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
@@ -57,6 +59,7 @@
 				9AAC417B2C74668B00AC0A60 /* MyApp.swift */,
 				9AAC417D2C74668B00AC0A60 /* ContentView.swift */,
 				9AAC418A2C7466F000AC0A60 /* UIKitViewControllerWrapper.swift */,
+				9A135C022CBE774300808EB3 /* ImageProcessor.swift */,
 				9AAC417F2C74668C00AC0A60 /* Assets.xcassets */,
 				9AAC41812C74668C00AC0A60 /* MyApp.entitlements */,
 				9AAC41822C74668C00AC0A60 /* Preview Content */,
@@ -100,7 +103,7 @@
 			attributes = {
 				BuildIndependentTargetsInParallel = 1;
 				LastSwiftUpdateCheck = 1540;
-				LastUpgradeCheck = 1540;
+				LastUpgradeCheck = 1600;
 				TargetAttributes = {
 					9AAC41772C74668B00AC0A60 = {
 						CreatedOnToolsVersion = 15.4;
@@ -144,6 +147,7 @@
 			files = (
 				9AAC418B2C7466F000AC0A60 /* UIKitViewControllerWrapper.swift in Sources */,
 				9AAC417E2C74668B00AC0A60 /* ContentView.swift in Sources */,
+				9A135C032CBE774500808EB3 /* ImageProcessor.swift in Sources */,
 				9AAC417C2C74668B00AC0A60 /* MyApp.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -185,6 +189,7 @@
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				COPY_PHASE_STRIP = NO;
+				DEAD_CODE_STRIPPING = YES;
 				DEBUG_INFORMATION_FORMAT = dwarf;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
@@ -246,6 +251,7 @@
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				COPY_PHASE_STRIP = NO;
+				DEAD_CODE_STRIPPING = YES;
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
@@ -273,6 +279,7 @@
 				CODE_SIGN_ENTITLEMENTS = MyApp/MyApp.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
+				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_ASSET_PATHS = "\"MyApp/Preview Content\"";
 				DEVELOPMENT_TEAM = 99WD9D6Y46;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -311,6 +318,7 @@
 				CODE_SIGN_ENTITLEMENTS = MyApp/MyApp.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
+				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_ASSET_PATHS = "\"MyApp/Preview Content\"";
 				DEVELOPMENT_TEAM = 99WD9D6Y46;
 				ENABLE_HARDENED_RUNTIME = YES;

MyApp/Assets.xcassets/Round_logo.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "filename" : "Round_logo.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

MyApp/ImageProcessor.swift

@@ -0,0 +1,136 @@
+//
+//  ImageProcessor.swift
+//  MyApp
+//
+//  Created by Cong Le on 10/15/24.
+//
+
+import UIKit
+
+/**
+ Defines the interface for image compression strategies.  This protocol ensures that all concrete strategies adhere to a consistent method signature.
+ */
+protocol ImageCompressionStrategy {
+    /// Compresses the given image and returns the compressed data or an error.
+    /// - Parameter image: The `UIImage` to compress.
+    /// - Returns: A `Result<Data, Error>` containing the compressed image data on success, or an `Error` on failure.
+    func compress(image: UIImage) -> Result<Data, Error>
+}
+
+/**
+ Implements JPEG compression strategy. Conforms to the `ImageCompressionStrategy` protocol.
+ */
+class JPEGCompression: ImageCompressionStrategy {
+
+    /// Compresses the input image using JPEG compression with a quality of 0.8.
+    /// - Parameter image: The `UIImage` to be compressed.
+    /// - Returns: A `Result<Data, Error>` containing the compressed JPEG data or an error if compression fails.
+    func compress(image: UIImage) -> Result<Data, Error> {
+        guard let data = image.jpegData(compressionQuality: 0.8) else {
+            return .failure(NSError(domain: "JPEGCompression", code: 0, userInfo: [NSLocalizedDescriptionKey: "JPEG compression failed"]))
+        }
+        return .success(data)
+    }
+}
+
+/**
+ Implements PNG compression strategy. Conforms to the `ImageCompressionStrategy` protocol.
+ */
+class PNGCompression: ImageCompressionStrategy {
+
+    /// Compresses the input image using PNG compression.
+    /// - Parameter image: The `UIImage` to be compressed.
+    /// - Returns: A `Result<Data, Error>` containing the compressed PNG data or an error if compression fails.
+    func compress(image: UIImage) -> Result<Data, Error> {
+        guard let data = image.pngData() else {
+            return .failure(NSError(domain: "PNGCompression", code: 0, userInfo: [NSLocalizedDescriptionKey: "PNG compression failed"]))
+        }
+        return .success(data)
+    }
+}
+
+
+
+// MARK: - Context Class
+/**
+ The context class that uses a concrete strategy to compress images.  Manages the currently selected compression strategy.
+ */
+class ImageProcessor {
+    /// The currently selected image compression strategy.
+    var compressionStrategy: ImageCompressionStrategy
+
+    /**
+     Initializes the `ImageProcessor` with a specific compression strategy.
+     - Parameter compressionStrategy: The initial `ImageCompressionStrategy` to use.
+     */
+    init(compressionStrategy: ImageCompressionStrategy) {
+        self.compressionStrategy = compressionStrategy
+    }
+
+    /**
+     Processes the given image using the currently assigned compression strategy.
+     - Parameter image: The `UIImage` to process.
+     - Returns: A `Result<Data, Error>` containing the compressed image data or an error if processing fails.
+     */
+    func processImage(image: UIImage) -> Result<Data, Error> {
+        return compressionStrategy.compress(image: image)
+    }
+
+    /**
+     Sets a new compression strategy for the image processor.
+     - Parameter strategy: The new `ImageCompressionStrategy` to use.
+     */
+    func setCompressionStrategy(strategy: ImageCompressionStrategy) {
+        self.compressionStrategy = strategy
+    }
+}
+
+/**
+ Represents the available image compression types. Used for selecting the appropriate strategy.
+ Conforms to `CaseIterable` and `RawRepresentable` for easy iteration and string conversion.
+ */
+enum CompressionType: CaseIterable, RawRepresentable {
+    case jpeg, png
+
+    typealias RawValue = String
+
+    /// The string representation of the compression type.
+    var rawValue: String {
+        switch self {
+        case .jpeg: return "jpeg"
+        case .png: return "png"
+        }
+    }
+
+    /**
+     Initializes a `CompressionType` from a raw string value.
+     - Parameter rawValue: The string representation of the compression type.
+     */
+    init?(rawValue: String) {
+        switch rawValue {
+        case "jpeg": self = .jpeg
+        case "png": self = .png
+        default: return nil
+        }
+    }
+}
+
+// MARK: - Strategy Factory (Advanced Usage)
+/**
+ A factory struct responsible for creating concrete `ImageCompressionStrategy` instances based on a given `CompressionType`.
+*/
+struct CompressionStrategyFactory {
+
+    /**
+     Creates and returns an `ImageCompressionStrategy` based on the specified compression type.
+     - Parameter type: The `CompressionType` indicating the desired strategy.
+     - Returns: An optional `ImageCompressionStrategy` instance. Returns `nil` if the compression type is not supported.
+     */
+    static func createStrategy(for type: CompressionType) -> ImageCompressionStrategy? {
+        switch type {
+        case .jpeg: return JPEGCompression()
+        case .png: return PNGCompression()
+        }
+    }
+}
+

MyApp/UIKitViewControllerWrapper.swift

@@ -25,9 +25,59 @@ struct UIKitViewControllerWrapper: UIViewControllerRepresentable {
 
 // Example UIKit view controller
 class MyUIKitViewController: UIViewController {
+
+
     override func viewDidLoad() {
         super.viewDidLoad()
         view.backgroundColor = .systemBlue
-        // Additional setup
+
+        // Simulate dynamic selection by iterating through all compression types
+        for compressionType in CompressionType.allCases {
+            performImageCompression(using: compressionType)
+        }
+    }
+
+    // Function to simulate usage of Image Compression Strategy
+    func performImageCompression(using compressionType: CompressionType) {
+        // Using the factory to create the selected compression strategy:
+        guard let strategy = CompressionStrategyFactory.createStrategy(for: compressionType) else {
+            print("Unsupported compression type selected.")
+            return
+        }
+        let imageProcessor = ImageProcessor(compressionStrategy: strategy)
+
+        // Replace "Round_logo" with the actual image name in your asset catalog
+        // or use another method to load the UIImage
+        guard let image = UIImage(named: "Round_logo") else {
+            print("Failed to load the image.")
+            return
+        }
+
+        // Retrieve original image data based on the selected compression type
+        let originalImageData: Data?
+        switch compressionType {
+        case .jpeg:
+            // Assuming the original image is best represented as JPEG for comparison
+            originalImageData = image.jpegData(compressionQuality: 1.0)
+        case .png:
+            // Assuming the original image is best represented as PNG for comparison
+            originalImageData = image.pngData()
+        }
+
+        if let originalData = originalImageData {
+            print("Compression Type: \(compressionType.rawValue.uppercased())")
+            print("Original image data size: \(originalData.count) bytes")
+        } else {
+            print("Failed to retrieve original image data.")
+        }
+
+        // Perform compression using the selected strategy
+        let result = imageProcessor.processImage(image: image)
+        switch result {
+        case .success(let compressedData):
+            print("Compressed image data size: \(compressedData.count) bytes\n")
+        case .failure(let error):
+            print("Image compression failed: \(error.localizedDescription)\n")
+        }
     }
 }