WIP.

Package.swift

@@ -5,6 +5,10 @@ import PackageDescription
 
 let package = Package(
     name: "CropImage",
+    platforms: [
+        .iOS(.v14),
+        .macOS(.v13)
+    ],
     products: [
         // Products define the executables and libraries a package produces, and make them visible to other packages.
         .library(
@@ -20,9 +24,6 @@ let package = Package(
         // Targets can depend on other targets in this package, and on products in packages this package depends on.
         .target(
             name: "CropImage",
-            dependencies: []),
+            dependencies: [])
-        .testTarget(
-            name: "CropImageTests",
-            dependencies: ["CropImage"]),
     ]
 )

Sources/CropImage/CropImage.swift

@@ -1,6 +0,0 @@
-public struct CropImage {
-    public private(set) var text = "Hello, World!"
-
-    public init() {
-    }
-}

Sources/CropImage/CropImageView.swift

@@ -0,0 +1,57 @@
+//
+//  CropImageView.swift
+//
+//
+//  Created by Shibo Lyu on 2023/7/21.
+//
+
+import SwiftUI
+
+public struct CropImageView: View {
+    var image: PlatformImage
+    var targetSize: CGSize
+    var onCrop: (PlatformImage) -> Void
+
+    @State private var offset: CGSize = .zero
+    @State private var scale: CGFloat = 1
+
+    public var body: some View {
+        ZStack {
+            MoveAndScalableImageView(offset: $offset, scale: $scale, image: image)
+            RectHoleShape(size: targetSize)
+                .fill(style: FillStyle(eoFill: true))
+                .foregroundColor(.black.opacity(0.6))
+                .allowsHitTesting(false)
+        }
+    }
+}
+
+struct CropImageView_Previews: PreviewProvider {
+    struct PreviewView: View {
+        @State private var croppedImage: PlatformImage? = nil
+
+        var body: some View {
+            VStack {
+                CropImageView(
+                    image: .init(contentsOfFile: "/Users/laosb/Downloads/png.png")!,
+                    targetSize: .init(width: 100, height: 100)
+                ) { _ in
+
+                }
+                if let croppedImage {
+                    #if os(macOS)
+                    Image(nsImage: croppedImage)
+                    #elseif os(iOS)
+                    Image(uiImage: croppedImage)
+                    #endif
+                } else {
+                    Text("Press \(Image(systemName: "checkmark.circle.fill")) to crop.")
+                }
+            }
+        }
+    }
+
+    static var previews: some View {
+        PreviewView()
+    }
+}

Sources/CropImage/MoveAndScalableImageView.swift

@@ -0,0 +1,73 @@
+//
+//  MoveAndScalableImageView.swift
+//
+//
+//  Created by Shibo Lyu on 2023/7/21.
+//
+
+import SwiftUI
+
+private extension CGSize {
+    static func + (lhs: CGSize, rhs: CGSize) -> CGSize {
+        .init(width: lhs.width + rhs.width, height: lhs.height + rhs.height)
+    }
+}
+
+struct MoveAndScalableImageView: View {
+    @Binding var offset: CGSize
+    @Binding var scale: CGFloat
+    var image: PlatformImage
+
+    @State private var tempOffset: CGSize = .zero
+    @State private var tempScale: CGFloat = 1
+
+    var body: some View {
+        ZStack {
+            #if os(macOS)
+            Image(nsImage: image)
+                .scaleEffect(scale * tempScale)
+                .offset(offset + tempOffset)
+            #elseif os(iOS)
+            Image(uiImage: image)
+                .scaleEffect(scale * tempScale)
+                .offset(offset + tempOffset)
+            #endif
+            Color.white.opacity(0.0001)
+                .gesture(
+                    DragGesture()
+                        .onChanged { value in
+                            tempOffset = value.translation
+                        }
+                        .onEnded { value in
+                            offset = offset + tempOffset
+                            tempOffset = .zero
+                        }
+                )
+                .gesture(
+                    MagnificationGesture()
+                        .onChanged { value in
+                            tempScale = value.magnitude
+                        }
+                        .onEnded { value in
+                            scale = scale * tempScale
+                            tempScale = 1
+                        }
+                )
+        }
+    }
+}
+
+struct MoveAndScalableImageView_Previews: PreviewProvider {
+    struct PreviewView: View {
+        @State private var offset: CGSize = .zero
+        @State private var scale: CGFloat = 1
+
+        var body: some View {
+            MoveAndScalableImageView(offset: $offset, scale: $scale, image: .init(contentsOfFile: "/Users/laosb/Downloads/png.png")!)
+        }
+    }
+
+    static var previews: some View {
+        PreviewView()
+    }
+}

Sources/CropImage/PlatformImage.swift

@@ -0,0 +1,16 @@
+//
+//  PlatformImage.swift
+//
+//
+//  Created by Shibo Lyu on 2023/7/21.
+//
+
+import Foundation
+
+#if os(macOS)
+import AppKit
+public typealias PlatformImage = NSImage
+#elseif os(iOS)
+import UIKit
+public typealias PlatformImage = UIImage
+#endif

Sources/CropImage/RectHoleShape.swift

@@ -0,0 +1,45 @@
+//
+//  RectHoleShape.swift
+//
+//
+//  Created by Shibo Lyu on 2023/7/21.
+//
+
+import SwiftUI
+
+struct RectHoleShape: Shape {
+    let size: CGSize
+    func path(in rect: CGRect) -> Path {
+        let path = CGMutablePath()
+        path.move(to: rect.origin)
+        path.addLine(to: .init(x: rect.maxX, y: rect.minY))
+        path.addLine(to: .init(x: rect.maxX, y: rect.maxY))
+        path.addLine(to: .init(x: rect.minX, y: rect.maxY))
+        path.addLine(to: rect.origin)
+        path.closeSubpath()
+
+        let newRect = CGRect(origin: .init(
+            x: rect.midX - size.width / 2.0,
+            y: rect.midY - size.height / 2.0
+        ), size: size)
+
+        path.move(to: newRect.origin)
+        path.addLine(to: .init(x: newRect.maxX, y: newRect.minY))
+        path.addLine(to: .init(x: newRect.maxX, y: newRect.maxY))
+        path.addLine(to: .init(x: newRect.minX, y: newRect.maxY))
+        path.addLine(to: newRect.origin)
+        path.closeSubpath()
+        return Path(path)
+    }
+}
+
+struct RectHoleShape_Previews: PreviewProvider {
+    static var previews: some View {
+        VStack {
+            RectHoleShape(size: .init(width: 100, height: 100))
+                .fill(style: FillStyle(eoFill: true))
+                .foregroundColor(.black.opacity(0.6))
+        }
+    }
+}
+

Tests/CropImageTests/CropImageTests.swift

@@ -1,11 +0,0 @@
-import XCTest
-@testable import CropImage
-
-final class CropImageTests: XCTestCase {
-    func testExample() throws {
-        // This is an example of a functional test case.
-        // Use XCTAssert and related functions to verify your tests produce the correct
-        // results.
-        XCTAssertEqual(CropImage().text, "Hello, World!")
-    }
-}