Enable StrictConcurrency

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.7
+// swift-tools-version: 5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -9,7 +9,7 @@ let package = Package(
         .library(name: "ZPLBuilder", targets: ["ZPLBuilder"]),
     ],
     targets: [
-        .target(name: "ZPLBuilder"),
+        .target(name: "ZPLBuilder", swiftSettings: [.enableExperimentalFeature("StrictConcurrency")]),
         .testTarget(name: "ZPLBuilderTests", dependencies: ["ZPLBuilder"]),
     ]
 )

Sources/ZPLBuilder/Commands/GraphicField.swift

@@ -27,7 +27,7 @@ public struct GraphicField: ZPLCommandConvertible {
         self.encoder = encoder
     }
 
-    public init(imageReader: ZPLImageReader, encoder: ZPLImageEncoder = .default) {
+    public init(imageReader: ZPLImageReader, encoder: ZPLImageEncoder = .init()) {
         self.encoder = encoder
         self.image = imageReader
     }
@@ -37,7 +37,7 @@ public struct GraphicField: ZPLCommandConvertible {
 import AppKit
 
 extension GraphicField {
-    public init(image: NSImage, size: CGSize? = nil, encoder: ZPLImageEncoder = .default) {
+    public init(image: NSImage, size: CGSize? = nil, encoder: ZPLImageEncoder = .init()) {
         if let cgImage = image.cgImage(forProposedRect: nil, context: nil, hints: nil),
            let image = ZPLCGImageReader(cgImage: cgImage, targetSize: size)
         {
@@ -51,7 +51,7 @@ extension GraphicField {
 import UIKit
 
 extension GraphicField {
-    public init(image: UIImage, size: CGSize? = nil, encoder: ZPLImageEncoder = .default) {
+    public init(image: UIImage, size: CGSize? = nil, encoder: ZPLImageEncoder = .init()) {
         if let cgImage = image.cgImage,
            let image = ZPLCGImageReader(cgImage: cgImage, targetSize: size)
         {

Sources/ZPLBuilder/Utils/ZPLGeometryUtils.swift

@@ -48,3 +48,18 @@ private func makeRect(aspectRatio: CGSize, boundingRect: CGRect) -> CGRect {
 
     return .init(origin: origin, size: size)
 }
+
+import UIKit
+
+class A: UIViewController {
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        let image = UIImage()
+        let encoder = ZPLImageEncoder(isCompressed: true)
+
+        _ = ZPL {
+            GraphicField(image: image, encoder: encoder)
+        }
+    }
+}

Sources/ZPLBuilder/Utils/ZPLImageEncoder/ZPLImage.swift

@@ -1,13 +1,13 @@
 //
-//  File.swift
-//  
+//  ZPLImage.swift
+//
 //
 //  Created by chen on 2024/5/4.
 //
 
 import Foundation
 
-public struct ZPLImage {
+public struct ZPLImage: Sendable {
     public var bytesPerRow: Int
     public var totalBytes: Int
     public var data: String

Sources/ZPLBuilder/Utils/ZPLImageEncoder/ZPLImageEncoder.swift

@@ -7,18 +7,26 @@
 
 import Foundation
 
-public class ZPLImageEncoder {
-    /// The default encoder of ``GraphicField``.
-    public static let `default` = ZPLImageEncoder()
-
+/// Encodes images into ZPL format.
+/// Supports both compressed and uncompressed encoding modes.
+public final class ZPLImageEncoder: Sendable {
     private static let componentValueSize = 8
 
-    public var isCompressed: Bool = false
-    public var whiteThreshold = 383
+    /// If true, uses compression for encoding; if false, generates uncompressed data.
+    public let isCompressed: Bool
 
-    public init() {
-
+    /// Threshold for determining black/white pixels.
+    public let whiteThreshold: Int
+
+    /// Initializes the encoder.
+    /// - Parameters:
+    ///   - isCompressed: Use compression mode. Default: false.
+    ///   - whiteThreshold: Black/white threshold. Default: 383 (50% gray).
+    public init(isCompressed: Bool = false, whiteThreshold: Int = 383) {
+        self.isCompressed = isCompressed
+        self.whiteThreshold = whiteThreshold
     }
+
 
     public func encode(imageReader: ZPLImageReader) -> ZPLImage? {
         guard let data = isCompressed ? makeCompressedData(imageReader: imageReader) : makeData(imageReader: imageReader),