feat: change titlebar text color based on background color

Author: humblehacker

MacHelix/MacHelixApp.swift

@@ -32,7 +32,7 @@ struct HelixApp: App {
                 .toolbar { ToolbarItem { Spacer() } } // empty toolbar forces title to left
                 .introspect(.window, on: .macOS(.v14)) { window in
                     window.titlebarAppearsTransparent = true
-                    NSApp.appearance = NSAppearance(named: .darkAqua)
+                    NSApp.appearance = NSAppearance(named: viewStore.isDarkMode ? .darkAqua : .aqua)
                 }
         }
         .windowStyle(.automatic)

Modules/Common/Color.swift

@@ -11,7 +11,9 @@ public struct Color: Equatable, Sendable {
     public let red: Int
     public let green: Int
     public let blue: Int
+}
 
+extension Color {
     public init(hexColorString: String) {
         // Ensure the string has the expected length
         guard hexColorString.count == 7 else { fatalError("malformed hex color string: \(hexColorString)") }
@@ -32,3 +34,23 @@ public struct Color: Equatable, Sendable {
 }
 
 
+// origin: https://chat.openai.com/share/23d90922-b701-4c91-b40c-08e58974ce11
+extension Color {
+    public func isDark() -> Bool {
+        let red = Double(red)/256
+        let green = Double(green)/256
+        let blue = Double(blue)/256
+
+        // Convert sRGB values to linear values
+        let linearRed = (red <= 0.04045) ? red / 12.92 : pow((red + 0.055) / 1.055, 2.4)
+        let linearGreen = (green <= 0.04045) ? green / 12.92 : pow((green + 0.055) / 1.055, 2.4)
+        let linearBlue = (blue <= 0.04045) ? blue / 12.92 : pow((blue + 0.055) / 1.055, 2.4)
+
+        // Calculate relative luminance
+        let luminance = 0.2126 * linearRed + 0.7152 * linearGreen + 0.0722 * linearBlue
+
+        // Use a threshold to determine if the color is dark
+        return luminance < 0.5
+    }
+}
+

Modules/Feature/AppFeature/AppFeature.swift

@@ -1,7 +1,8 @@
 import ComposableArchitecture
+import Common
 import Foundation
-import TerminalFeature
 import HelixFeature
+import TerminalFeature
 
 public enum Position {
     case left
@@ -18,6 +19,8 @@ public struct AppFeature: Reducer {
         public var mouseReportingEnabled: Bool = true
         public var currentDocumentURL: URL?
         public var helixState: HelixFeature.State
+        public var isDarkMode: Bool = true
+
         public init(helixState: HelixFeature.State = HelixFeature.State()) {
             self.helixState = helixState
         }
@@ -44,6 +47,10 @@ public struct AppFeature: Reducer {
                 state.currentDocumentURL = url
                 return .none
 
+            case .helix(.themeChanged(bgColor: let bgColor)):
+                state.isDarkMode = bgColor.isDark()
+                return .none
+
             case .helix(_):
                 return .none
 

Modules/Feature/AppFeature/HelixView.swift

@@ -42,6 +42,6 @@ public struct HelixView: View {
 
 extension Common.Color {
     func toSwiftUI() -> SwiftUI.Color {
-        SwiftUI.Color(red: Double(red)/256, green: Double(green)/256, blue: Double(blue)/256)
+        Color(red: Double(red)/256, green: Double(green)/256, blue: Double(blue)/256)
     }
 }

Modules/Feature/HelixFeature/HelixFeature.swift

@@ -114,8 +114,8 @@ public struct HelixFeature: Reducer, Sendable {
         let rest = parts
             .dropFirst()
             .joined()
-            .trimmingCharacters(in: .whitespacesAndNewlines)
             .components(separatedBy: ",")
+            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
 
         return (command, rest)
     }