Fix ColorPicker's opacity for macOS 14

app/xcode/Package.swift

@@ -7,7 +7,7 @@ let package = Package(
     defaultLocalization: "en",
     platforms: [.macOS(.v13)],
     products: [
-        .library(name: "VCam", targets: ["VCamUI", "VCamMedia", "VCamBridge"]),
+        .library(name: "VCam", targets: ["VCamUI", "VCamMedia", "VCamBridge", "VCamWorkaround"]),
         .library(name: "VCamMedia", targets: ["VCamMedia"]),
         .library(name: "VCamCamera", targets: ["VCamCamera"]),
 
@@ -32,6 +32,7 @@ let package = Package(
         .target(name: "VCamLogger", dependencies: []),
         .target(name: "VCamDefaults", dependencies: []),
         .target(name: "VCamAppExtension", dependencies: []),
+        .target(name: "VCamWorkaround", dependencies: []),
 
         .testTarget(name: "VCamEntityTests", dependencies: ["VCamEntity"]),
         .testTarget(name: "VCamCameraTests", dependencies: ["VCamCamera"]),

app/xcode/Sources/VCamWorkaround/Workaround.swift

@@ -0,0 +1,19 @@
+//
+//  Workaround.swift
+//
+//
+//  Created by Tatsuya Tanaka on 2023/10/07.
+//
+
+import AppKit
+
+public enum Workaround {
+    public static func fixColorPickerOpacity_macOS14() {
+        if #available(macOS 14, *) {
+            // The root cause is unknown, but under specific conditions on macOS 14,
+            // changes to the opacity of SwiftUI's ColorPicker might not be reflected.
+            // Calling the following can avoid the issue.
+            NSColorPanel.shared.showsAlpha = true
+        }
+    }
+}